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linux_dsm_epyc7002/arch/powerpc/kvm/book3s_hv_rmhandlers.S

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KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*
* Derived from book3s_rmhandlers.S and other files, which are:
*
* Copyright SUSE Linux Products GmbH 2009
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#include <asm/ppc_asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately This makes arch/powerpc/kvm/book3s_rmhandlers.S and arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as separate compilation units rather than having them #included in arch/powerpc/kernel/exceptions-64s.S. We no longer have any conditional branches between the exception prologs in exceptions-64s.S and the KVM handlers, so there is no need to keep their contents close together in the vmlinux image. In their current location, they are using up part of the limited space between the first-level interrupt handlers and the firmware NMI data area at offset 0x7000, and with some kernel configurations this area will overflow (e.g. allyesconfig), leading to an "attempt to .org backwards" error when compiling exceptions-64s.S. Moving them out requires that we add some #includes that the book3s_{,hv_}rmhandlers.S code was previously getting implicitly via exceptions-64s.S. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:41:11 +07:00
#include <asm/mmu.h>
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
#include <asm/page.h>
KVM: PPC: Assemble book3s{,_hv}_rmhandlers.S separately This makes arch/powerpc/kvm/book3s_rmhandlers.S and arch/powerpc/kvm/book3s_hv_rmhandlers.S be assembled as separate compilation units rather than having them #included in arch/powerpc/kernel/exceptions-64s.S. We no longer have any conditional branches between the exception prologs in exceptions-64s.S and the KVM handlers, so there is no need to keep their contents close together in the vmlinux image. In their current location, they are using up part of the limited space between the first-level interrupt handlers and the firmware NMI data area at offset 0x7000, and with some kernel configurations this area will overflow (e.g. allyesconfig), leading to an "attempt to .org backwards" error when compiling exceptions-64s.S. Moving them out requires that we add some #includes that the book3s_{,hv_}rmhandlers.S code was previously getting implicitly via exceptions-64s.S. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:41:11 +07:00
#include <asm/ptrace.h>
#include <asm/hvcall.h>
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
#include <asm/asm-offsets.h>
#include <asm/exception-64s.h>
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
#include <asm/kvm_book3s_asm.h>
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/*****************************************************************************
* *
* Real Mode handlers that need to be in the linear mapping *
* *
****************************************************************************/
.globl kvmppc_skip_interrupt
kvmppc_skip_interrupt:
mfspr r13,SPRN_SRR0
addi r13,r13,4
mtspr SPRN_SRR0,r13
GET_SCRATCH0(r13)
rfid
b .
.globl kvmppc_skip_Hinterrupt
kvmppc_skip_Hinterrupt:
mfspr r13,SPRN_HSRR0
addi r13,r13,4
mtspr SPRN_HSRR0,r13
GET_SCRATCH0(r13)
hrfid
b .
/*
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
* Call kvmppc_hv_entry in real mode.
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
* Must be called with interrupts hard-disabled.
*
* Input Registers:
*
* LR = return address to continue at after eventually re-enabling MMU
*/
_GLOBAL(kvmppc_hv_entry_trampoline)
mfmsr r10
LOAD_REG_ADDR(r5, kvmppc_hv_entry)
li r0,MSR_RI
andc r0,r10,r0
li r6,MSR_IR | MSR_DR
andc r6,r10,r6
mtmsrd r0,1 /* clear RI in MSR */
mtsrr0 r5
mtsrr1 r6
RFI
#define ULONG_SIZE 8
#define VCPU_GPR(n) (VCPU_GPRS + (n * ULONG_SIZE))
/******************************************************************************
* *
* Entry code *
* *
*****************************************************************************/
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
#define XICS_XIRR 4
#define XICS_QIRR 0xc
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
#define XICS_IPI 2 /* interrupt source # for IPIs */
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
/*
* We come in here when wakened from nap mode on a secondary hw thread.
* Relocation is off and most register values are lost.
* r13 points to the PACA.
*/
.globl kvm_start_guest
kvm_start_guest:
ld r1,PACAEMERGSP(r13)
subi r1,r1,STACK_FRAME_OVERHEAD
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
ld r2,PACATOC(r13)
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
li r0,KVM_HWTHREAD_IN_KVM
stb r0,HSTATE_HWTHREAD_STATE(r13)
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
/* NV GPR values from power7_idle() will no longer be valid */
li r0,1
stb r0,PACA_NAPSTATELOST(r13)
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
/* get vcpu pointer, NULL if we have no vcpu to run */
ld r4,HSTATE_KVM_VCPU(r13)
cmpdi cr1,r4,0
/* Check the wake reason in SRR1 to see why we got here */
mfspr r3,SPRN_SRR1
rlwinm r3,r3,44-31,0x7 /* extract wake reason field */
cmpwi r3,4 /* was it an external interrupt? */
bne 27f
/*
* External interrupt - for now assume it is an IPI, since we
* should never get any other interrupts sent to offline threads.
* Only do this for secondary threads.
*/
beq cr1,25f
lwz r3,VCPU_PTID(r4)
cmpwi r3,0
beq 27f
25: ld r5,HSTATE_XICS_PHYS(r13)
li r0,0xff
li r6,XICS_QIRR
li r7,XICS_XIRR
lwzcix r8,r5,r7 /* get and ack the interrupt */
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
sync
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
clrldi. r9,r8,40 /* get interrupt source ID. */
beq 27f /* none there? */
cmpwi r9,XICS_IPI
bne 26f
stbcix r0,r5,r6 /* clear IPI */
26: stwcix r8,r5,r7 /* EOI the interrupt */
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
27: /* XXX should handle hypervisor maintenance interrupts etc. here */
/* if we have no vcpu to run, go back to sleep */
beq cr1,kvm_no_guest
/* were we napping due to cede? */
lbz r0,HSTATE_NAPPING(r13)
cmpwi r0,0
bne kvm_end_cede
powerpc: Provide a way for KVM to indicate that NV GPR values are lost This fixes a problem where a CPU thread coming out of nap mode can think it has valid values in the nonvolatile GPRs (r14 - r31) as saved away in power7_idle, but in fact the values have been trashed because the thread was used for KVM in the mean time. The result is that the thread crashes because code that called power7_idle (e.g., pnv_smp_cpu_kill_self()) goes to use values in registers that have been trashed. The bit field in SRR1 that tells whether state was lost only reflects the most recent nap, which may not have been the nap instruction in power7_idle. So we need an extra PACA field to indicate that state has been lost even if SRR1 indicates that the most recent nap didn't lose state. We clear this field when saving the state in power7_idle, we set it to a non-zero value when we use the thread for KVM, and we test it in power7_wakeup_noloss. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-12-06 02:47:26 +07:00
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
.global kvmppc_hv_entry
kvmppc_hv_entry:
/* Required state:
*
* R4 = vcpu pointer
* MSR = ~IR|DR
* R13 = PACA
* R1 = host R1
* all other volatile GPRS = free
*/
mflr r0
std r0, HSTATE_VMHANDLER(r13)
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
/* Set partition DABR */
/* Do this before re-enabling PMU to avoid P7 DABR corruption bug */
li r5,3
ld r6,VCPU_DABR(r4)
mtspr SPRN_DABRX,r5
mtspr SPRN_DABR,r6
BEGIN_FTR_SECTION
isync
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Load guest PMU registers */
/* R4 is live here (vcpu pointer) */
li r3, 1
sldi r3, r3, 31 /* MMCR0_FC (freeze counters) bit */
mtspr SPRN_MMCR0, r3 /* freeze all counters, disable ints */
isync
lwz r3, VCPU_PMC(r4) /* always load up guest PMU registers */
lwz r5, VCPU_PMC + 4(r4) /* to prevent information leak */
lwz r6, VCPU_PMC + 8(r4)
lwz r7, VCPU_PMC + 12(r4)
lwz r8, VCPU_PMC + 16(r4)
lwz r9, VCPU_PMC + 20(r4)
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
lwz r10, VCPU_PMC + 24(r4)
lwz r11, VCPU_PMC + 28(r4)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mtspr SPRN_PMC1, r3
mtspr SPRN_PMC2, r5
mtspr SPRN_PMC3, r6
mtspr SPRN_PMC4, r7
mtspr SPRN_PMC5, r8
mtspr SPRN_PMC6, r9
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
mtspr SPRN_PMC7, r10
mtspr SPRN_PMC8, r11
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
ld r3, VCPU_MMCR(r4)
ld r5, VCPU_MMCR + 8(r4)
ld r6, VCPU_MMCR + 16(r4)
mtspr SPRN_MMCR1, r5
mtspr SPRN_MMCRA, r6
mtspr SPRN_MMCR0, r3
isync
/* Load up FP, VMX and VSX registers */
bl kvmppc_load_fp
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
ld r14, VCPU_GPR(r14)(r4)
ld r15, VCPU_GPR(r15)(r4)
ld r16, VCPU_GPR(r16)(r4)
ld r17, VCPU_GPR(r17)(r4)
ld r18, VCPU_GPR(r18)(r4)
ld r19, VCPU_GPR(r19)(r4)
ld r20, VCPU_GPR(r20)(r4)
ld r21, VCPU_GPR(r21)(r4)
ld r22, VCPU_GPR(r22)(r4)
ld r23, VCPU_GPR(r23)(r4)
ld r24, VCPU_GPR(r24)(r4)
ld r25, VCPU_GPR(r25)(r4)
ld r26, VCPU_GPR(r26)(r4)
ld r27, VCPU_GPR(r27)(r4)
ld r28, VCPU_GPR(r28)(r4)
ld r29, VCPU_GPR(r29)(r4)
ld r30, VCPU_GPR(r30)(r4)
ld r31, VCPU_GPR(r31)(r4)
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Switch DSCR to guest value */
ld r5, VCPU_DSCR(r4)
mtspr SPRN_DSCR, r5
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/*
* Set the decrementer to the guest decrementer.
*/
ld r8,VCPU_DEC_EXPIRES(r4)
mftb r7
subf r3,r7,r8
mtspr SPRN_DEC,r3
stw r3,VCPU_DEC(r4)
ld r5, VCPU_SPRG0(r4)
ld r6, VCPU_SPRG1(r4)
ld r7, VCPU_SPRG2(r4)
ld r8, VCPU_SPRG3(r4)
mtspr SPRN_SPRG0, r5
mtspr SPRN_SPRG1, r6
mtspr SPRN_SPRG2, r7
mtspr SPRN_SPRG3, r8
/* Save R1 in the PACA */
std r1, HSTATE_HOST_R1(r13)
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
/* Increment yield count if they have a VPA */
ld r3, VCPU_VPA(r4)
cmpdi r3, 0
beq 25f
lwz r5, LPPACA_YIELDCOUNT(r3)
addi r5, r5, 1
stw r5, LPPACA_YIELDCOUNT(r3)
25:
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Load up DAR and DSISR */
ld r5, VCPU_DAR(r4)
lwz r6, VCPU_DSISR(r4)
mtspr SPRN_DAR, r5
mtspr SPRN_DSISR, r6
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Restore AMR and UAMOR, set AMOR to all 1s */
ld r5,VCPU_AMR(r4)
ld r6,VCPU_UAMOR(r4)
li r7,-1
mtspr SPRN_AMR,r5
mtspr SPRN_UAMOR,r6
mtspr SPRN_AMOR,r7
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Clear out SLB */
li r6,0
slbmte r6,r6
slbia
ptesync
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
b 30f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
/*
* POWER7 host -> guest partition switch code.
* We don't have to lock against concurrent tlbies,
* but we do have to coordinate across hardware threads.
*/
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
/* Increment entry count iff exit count is zero. */
ld r5,HSTATE_KVM_VCORE(r13)
addi r9,r5,VCORE_ENTRY_EXIT
21: lwarx r3,0,r9
cmpwi r3,0x100 /* any threads starting to exit? */
bge secondary_too_late /* if so we're too late to the party */
addi r3,r3,1
stwcx. r3,0,r9
bne 21b
/* Primary thread switches to guest partition. */
KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests This adds infrastructure which will be needed to allow book3s_hv KVM to run on older POWER processors, including PPC970, which don't support the Virtual Real Mode Area (VRMA) facility, but only the Real Mode Offset (RMO) facility. These processors require a physically contiguous, aligned area of memory for each guest. When the guest does an access in real mode (MMU off), the address is compared against a limit value, and if it is lower, the address is ORed with an offset value (from the Real Mode Offset Register (RMOR)) and the result becomes the real address for the access. The size of the RMA has to be one of a set of supported values, which usually includes 64MB, 128MB, 256MB and some larger powers of 2. Since we are unlikely to be able to allocate 64MB or more of physically contiguous memory after the kernel has been running for a while, we allocate a pool of RMAs at boot time using the bootmem allocator. The size and number of the RMAs can be set using the kvm_rma_size=xx and kvm_rma_count=xx kernel command line options. KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability of the pool of preallocated RMAs. The capability value is 1 if the processor can use an RMA but doesn't require one (because it supports the VRMA facility), or 2 if the processor requires an RMA for each guest. This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the pool and returns a file descriptor which can be used to map the RMA. It also returns the size of the RMA in the argument structure. Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION ioctl calls from userspace. To cope with this, we now preallocate the kvm->arch.ram_pginfo array when the VM is created with a size sufficient for up to 64GB of guest memory. Subsequently we will get rid of this array and use memory associated with each memslot instead. This moves most of the code that translates the user addresses into host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level to kvmppc_core_prepare_memory_region. Also, instead of having to look up the VMA for each page in order to check the page size, we now check that the pages we get are compound pages of 16MB. However, if we are adding memory that is mapped to an RMA, we don't bother with calling get_user_pages_fast and instead just offset from the base pfn for the RMA. Typically the RMA gets added after vcpus are created, which makes it inconvenient to have the LPCR (logical partition control register) value in the vcpu->arch struct, since the LPCR controls whether the processor uses RMA or VRMA for the guest. This moves the LPCR value into the kvm->arch struct and arranges for the MER (mediated external request) bit, which is the only bit that varies between vcpus, to be set in assembly code when going into the guest if there is a pending external interrupt request. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:25:44 +07:00
ld r9,VCPU_KVM(r4) /* pointer to struct kvm */
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
lwz r6,VCPU_PTID(r4)
cmpwi r6,0
bne 20f
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
ld r6,KVM_SDR1(r9)
lwz r7,KVM_LPID(r9)
li r0,LPID_RSVD /* switch to reserved LPID */
mtspr SPRN_LPID,r0
ptesync
mtspr SPRN_SDR1,r6 /* switch to partition page table */
mtspr SPRN_LPID,r7
isync
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
li r0,1
stb r0,VCORE_IN_GUEST(r5) /* signal secondaries to continue */
b 10f
/* Secondary threads wait for primary to have done partition switch */
20: lbz r0,VCORE_IN_GUEST(r5)
cmpwi r0,0
beq 20b
KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests This adds infrastructure which will be needed to allow book3s_hv KVM to run on older POWER processors, including PPC970, which don't support the Virtual Real Mode Area (VRMA) facility, but only the Real Mode Offset (RMO) facility. These processors require a physically contiguous, aligned area of memory for each guest. When the guest does an access in real mode (MMU off), the address is compared against a limit value, and if it is lower, the address is ORed with an offset value (from the Real Mode Offset Register (RMOR)) and the result becomes the real address for the access. The size of the RMA has to be one of a set of supported values, which usually includes 64MB, 128MB, 256MB and some larger powers of 2. Since we are unlikely to be able to allocate 64MB or more of physically contiguous memory after the kernel has been running for a while, we allocate a pool of RMAs at boot time using the bootmem allocator. The size and number of the RMAs can be set using the kvm_rma_size=xx and kvm_rma_count=xx kernel command line options. KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability of the pool of preallocated RMAs. The capability value is 1 if the processor can use an RMA but doesn't require one (because it supports the VRMA facility), or 2 if the processor requires an RMA for each guest. This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the pool and returns a file descriptor which can be used to map the RMA. It also returns the size of the RMA in the argument structure. Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION ioctl calls from userspace. To cope with this, we now preallocate the kvm->arch.ram_pginfo array when the VM is created with a size sufficient for up to 64GB of guest memory. Subsequently we will get rid of this array and use memory associated with each memslot instead. This moves most of the code that translates the user addresses into host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level to kvmppc_core_prepare_memory_region. Also, instead of having to look up the VMA for each page in order to check the page size, we now check that the pages we get are compound pages of 16MB. However, if we are adding memory that is mapped to an RMA, we don't bother with calling get_user_pages_fast and instead just offset from the base pfn for the RMA. Typically the RMA gets added after vcpus are created, which makes it inconvenient to have the LPCR (logical partition control register) value in the vcpu->arch struct, since the LPCR controls whether the processor uses RMA or VRMA for the guest. This moves the LPCR value into the kvm->arch struct and arranges for the MER (mediated external request) bit, which is the only bit that varies between vcpus, to be set in assembly code when going into the guest if there is a pending external interrupt request. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:25:44 +07:00
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
/* Set LPCR and RMOR. */
KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests This adds infrastructure which will be needed to allow book3s_hv KVM to run on older POWER processors, including PPC970, which don't support the Virtual Real Mode Area (VRMA) facility, but only the Real Mode Offset (RMO) facility. These processors require a physically contiguous, aligned area of memory for each guest. When the guest does an access in real mode (MMU off), the address is compared against a limit value, and if it is lower, the address is ORed with an offset value (from the Real Mode Offset Register (RMOR)) and the result becomes the real address for the access. The size of the RMA has to be one of a set of supported values, which usually includes 64MB, 128MB, 256MB and some larger powers of 2. Since we are unlikely to be able to allocate 64MB or more of physically contiguous memory after the kernel has been running for a while, we allocate a pool of RMAs at boot time using the bootmem allocator. The size and number of the RMAs can be set using the kvm_rma_size=xx and kvm_rma_count=xx kernel command line options. KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability of the pool of preallocated RMAs. The capability value is 1 if the processor can use an RMA but doesn't require one (because it supports the VRMA facility), or 2 if the processor requires an RMA for each guest. This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the pool and returns a file descriptor which can be used to map the RMA. It also returns the size of the RMA in the argument structure. Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION ioctl calls from userspace. To cope with this, we now preallocate the kvm->arch.ram_pginfo array when the VM is created with a size sufficient for up to 64GB of guest memory. Subsequently we will get rid of this array and use memory associated with each memslot instead. This moves most of the code that translates the user addresses into host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level to kvmppc_core_prepare_memory_region. Also, instead of having to look up the VMA for each page in order to check the page size, we now check that the pages we get are compound pages of 16MB. However, if we are adding memory that is mapped to an RMA, we don't bother with calling get_user_pages_fast and instead just offset from the base pfn for the RMA. Typically the RMA gets added after vcpus are created, which makes it inconvenient to have the LPCR (logical partition control register) value in the vcpu->arch struct, since the LPCR controls whether the processor uses RMA or VRMA for the guest. This moves the LPCR value into the kvm->arch struct and arranges for the MER (mediated external request) bit, which is the only bit that varies between vcpus, to be set in assembly code when going into the guest if there is a pending external interrupt request. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:25:44 +07:00
10: ld r8,KVM_LPCR(r9)
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
mtspr SPRN_LPCR,r8
KVM: PPC: Allocate RMAs (Real Mode Areas) at boot for use by guests This adds infrastructure which will be needed to allow book3s_hv KVM to run on older POWER processors, including PPC970, which don't support the Virtual Real Mode Area (VRMA) facility, but only the Real Mode Offset (RMO) facility. These processors require a physically contiguous, aligned area of memory for each guest. When the guest does an access in real mode (MMU off), the address is compared against a limit value, and if it is lower, the address is ORed with an offset value (from the Real Mode Offset Register (RMOR)) and the result becomes the real address for the access. The size of the RMA has to be one of a set of supported values, which usually includes 64MB, 128MB, 256MB and some larger powers of 2. Since we are unlikely to be able to allocate 64MB or more of physically contiguous memory after the kernel has been running for a while, we allocate a pool of RMAs at boot time using the bootmem allocator. The size and number of the RMAs can be set using the kvm_rma_size=xx and kvm_rma_count=xx kernel command line options. KVM exports a new capability, KVM_CAP_PPC_RMA, to signal the availability of the pool of preallocated RMAs. The capability value is 1 if the processor can use an RMA but doesn't require one (because it supports the VRMA facility), or 2 if the processor requires an RMA for each guest. This adds a new ioctl, KVM_ALLOCATE_RMA, which allocates an RMA from the pool and returns a file descriptor which can be used to map the RMA. It also returns the size of the RMA in the argument structure. Having an RMA means we will get multiple KMV_SET_USER_MEMORY_REGION ioctl calls from userspace. To cope with this, we now preallocate the kvm->arch.ram_pginfo array when the VM is created with a size sufficient for up to 64GB of guest memory. Subsequently we will get rid of this array and use memory associated with each memslot instead. This moves most of the code that translates the user addresses into host pfns (page frame numbers) out of kvmppc_prepare_vrma up one level to kvmppc_core_prepare_memory_region. Also, instead of having to look up the VMA for each page in order to check the page size, we now check that the pages we get are compound pages of 16MB. However, if we are adding memory that is mapped to an RMA, we don't bother with calling get_user_pages_fast and instead just offset from the base pfn for the RMA. Typically the RMA gets added after vcpus are created, which makes it inconvenient to have the LPCR (logical partition control register) value in the vcpu->arch struct, since the LPCR controls whether the processor uses RMA or VRMA for the guest. This moves the LPCR value into the kvm->arch struct and arranges for the MER (mediated external request) bit, which is the only bit that varies between vcpus, to be set in assembly code when going into the guest if there is a pending external interrupt request. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:25:44 +07:00
ld r8,KVM_RMOR(r9)
mtspr SPRN_RMOR,r8
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
isync
/* Check if HDEC expires soon */
mfspr r3,SPRN_HDEC
cmpwi r3,10
li r12,BOOK3S_INTERRUPT_HV_DECREMENTER
mr r9,r4
blt hdec_soon
/*
* Invalidate the TLB if we could possibly have stale TLB
* entries for this partition on this core due to the use
* of tlbiel.
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
* XXX maybe only need this on primary thread?
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
*/
ld r9,VCPU_KVM(r4) /* pointer to struct kvm */
lwz r5,VCPU_VCPUID(r4)
lhz r6,PACAPACAINDEX(r13)
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
rldimi r6,r5,0,62 /* XXX map as if threads 1:1 p:v */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
lhz r8,VCPU_LAST_CPU(r4)
sldi r7,r6,1 /* see if this is the same vcpu */
add r7,r7,r9 /* as last ran on this pcpu */
lhz r0,KVM_LAST_VCPU(r7)
cmpw r6,r8 /* on the same cpu core as last time? */
bne 3f
cmpw r0,r5 /* same vcpu as this core last ran? */
beq 1f
3: sth r6,VCPU_LAST_CPU(r4) /* if not, invalidate partition TLB */
sth r5,KVM_LAST_VCPU(r7)
li r6,128
mtctr r6
li r7,0x800 /* IS field = 0b10 */
ptesync
2: tlbiel r7
addi r7,r7,0x1000
bdnz 2b
ptesync
1:
/* Save purr/spurr */
mfspr r5,SPRN_PURR
mfspr r6,SPRN_SPURR
std r5,HSTATE_PURR(r13)
std r6,HSTATE_SPURR(r13)
ld r7,VCPU_PURR(r4)
ld r8,VCPU_SPURR(r4)
mtspr SPRN_PURR,r7
mtspr SPRN_SPURR,r8
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
b 31f
/*
* PPC970 host -> guest partition switch code.
* We have to lock against concurrent tlbies,
* using native_tlbie_lock to lock against host tlbies
* and kvm->arch.tlbie_lock to lock against guest tlbies.
* We also have to invalidate the TLB since its
* entries aren't tagged with the LPID.
*/
30: ld r9,VCPU_KVM(r4) /* pointer to struct kvm */
/* first take native_tlbie_lock */
.section ".toc","aw"
toc_tlbie_lock:
.tc native_tlbie_lock[TC],native_tlbie_lock
.previous
ld r3,toc_tlbie_lock@toc(2)
lwz r8,PACA_LOCK_TOKEN(r13)
24: lwarx r0,0,r3
cmpwi r0,0
bne 24b
stwcx. r8,0,r3
bne 24b
isync
ld r7,KVM_LPCR(r9) /* use kvm->arch.lpcr to store HID4 */
li r0,0x18f
rotldi r0,r0,HID4_LPID5_SH /* all lpid bits in HID4 = 1 */
or r0,r7,r0
ptesync
sync
mtspr SPRN_HID4,r0 /* switch to reserved LPID */
isync
li r0,0
stw r0,0(r3) /* drop native_tlbie_lock */
/* invalidate the whole TLB */
li r0,256
mtctr r0
li r6,0
25: tlbiel r6
addi r6,r6,0x1000
bdnz 25b
ptesync
/* Take the guest's tlbie_lock */
addi r3,r9,KVM_TLBIE_LOCK
24: lwarx r0,0,r3
cmpwi r0,0
bne 24b
stwcx. r8,0,r3
bne 24b
isync
ld r6,KVM_SDR1(r9)
mtspr SPRN_SDR1,r6 /* switch to partition page table */
/* Set up HID4 with the guest's LPID etc. */
sync
mtspr SPRN_HID4,r7
isync
/* drop the guest's tlbie_lock */
li r0,0
stw r0,0(r3)
/* Check if HDEC expires soon */
mfspr r3,SPRN_HDEC
cmpwi r3,10
li r12,BOOK3S_INTERRUPT_HV_DECREMENTER
mr r9,r4
blt hdec_soon
/* Enable HDEC interrupts */
mfspr r0,SPRN_HID0
li r3,1
rldimi r0,r3, HID0_HDICE_SH, 64-HID0_HDICE_SH-1
sync
mtspr SPRN_HID0,r0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Load up guest SLB entries */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
31: lwz r5,VCPU_SLB_MAX(r4)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
cmpwi r5,0
beq 9f
mtctr r5
addi r6,r4,VCPU_SLB
1: ld r8,VCPU_SLB_E(r6)
ld r9,VCPU_SLB_V(r6)
slbmte r9,r8
addi r6,r6,VCPU_SLB_SIZE
bdnz 1b
9:
/* Restore state of CTRL run bit; assume 1 on entry */
lwz r5,VCPU_CTRL(r4)
andi. r5,r5,1
bne 4f
mfspr r6,SPRN_CTRLF
clrrdi r6,r6,1
mtspr SPRN_CTRLT,r6
4:
ld r6, VCPU_CTR(r4)
lwz r7, VCPU_XER(r4)
mtctr r6
mtxer r7
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
kvmppc_cede_reentry: /* r4 = vcpu, r13 = paca */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
ld r6, VCPU_SRR0(r4)
ld r7, VCPU_SRR1(r4)
ld r10, VCPU_PC(r4)
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
ld r11, VCPU_MSR(r4) /* r11 = vcpu->arch.msr & ~MSR_HV */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
rldicl r11, r11, 63 - MSR_HV_LG, 1
rotldi r11, r11, 1 + MSR_HV_LG
ori r11, r11, MSR_ME
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
/* Check if we can deliver an external or decrementer interrupt now */
ld r0,VCPU_PENDING_EXC(r4)
li r8,(1 << BOOK3S_IRQPRIO_EXTERNAL)
oris r8,r8,(1 << BOOK3S_IRQPRIO_EXTERNAL_LEVEL)@h
and r0,r0,r8
cmpdi cr1,r0,0
andi. r0,r11,MSR_EE
beq cr1,11f
BEGIN_FTR_SECTION
mfspr r8,SPRN_LPCR
ori r8,r8,LPCR_MER
mtspr SPRN_LPCR,r8
isync
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
beq 5f
li r0,BOOK3S_INTERRUPT_EXTERNAL
12: mr r6,r10
mr r10,r0
mr r7,r11
li r11,(MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
rotldi r11,r11,63
b 5f
11: beq 5f
mfspr r0,SPRN_DEC
cmpwi r0,0
li r0,BOOK3S_INTERRUPT_DECREMENTER
blt 12b
/* Move SRR0 and SRR1 into the respective regs */
5: mtspr SPRN_SRR0, r6
mtspr SPRN_SRR1, r7
li r0,0
stb r0,VCPU_CEDED(r4) /* cancel cede */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
fast_guest_return:
mtspr SPRN_HSRR0,r10
mtspr SPRN_HSRR1,r11
/* Activate guest mode, so faults get handled by KVM */
li r9, KVM_GUEST_MODE_GUEST
stb r9, HSTATE_IN_GUEST(r13)
/* Enter guest */
ld r5, VCPU_LR(r4)
lwz r6, VCPU_CR(r4)
mtlr r5
mtcr r6
ld r0, VCPU_GPR(r0)(r4)
ld r1, VCPU_GPR(r1)(r4)
ld r2, VCPU_GPR(r2)(r4)
ld r3, VCPU_GPR(r3)(r4)
ld r5, VCPU_GPR(r5)(r4)
ld r6, VCPU_GPR(r6)(r4)
ld r7, VCPU_GPR(r7)(r4)
ld r8, VCPU_GPR(r8)(r4)
ld r9, VCPU_GPR(r9)(r4)
ld r10, VCPU_GPR(r10)(r4)
ld r11, VCPU_GPR(r11)(r4)
ld r12, VCPU_GPR(r12)(r4)
ld r13, VCPU_GPR(r13)(r4)
ld r4, VCPU_GPR(r4)(r4)
hrfid
b .
/******************************************************************************
* *
* Exit code *
* *
*****************************************************************************/
/*
* We come here from the first-level interrupt handlers.
*/
.globl kvmppc_interrupt
kvmppc_interrupt:
/*
* Register contents:
* R12 = interrupt vector
* R13 = PACA
* guest CR, R12 saved in shadow VCPU SCRATCH1/0
* guest R13 saved in SPRN_SCRATCH0
*/
/* abuse host_r2 as third scratch area; we get r2 from PACATOC(r13) */
std r9, HSTATE_HOST_R2(r13)
ld r9, HSTATE_KVM_VCPU(r13)
/* Save registers */
std r0, VCPU_GPR(r0)(r9)
std r1, VCPU_GPR(r1)(r9)
std r2, VCPU_GPR(r2)(r9)
std r3, VCPU_GPR(r3)(r9)
std r4, VCPU_GPR(r4)(r9)
std r5, VCPU_GPR(r5)(r9)
std r6, VCPU_GPR(r6)(r9)
std r7, VCPU_GPR(r7)(r9)
std r8, VCPU_GPR(r8)(r9)
ld r0, HSTATE_HOST_R2(r13)
std r0, VCPU_GPR(r9)(r9)
std r10, VCPU_GPR(r10)(r9)
std r11, VCPU_GPR(r11)(r9)
ld r3, HSTATE_SCRATCH0(r13)
lwz r4, HSTATE_SCRATCH1(r13)
std r3, VCPU_GPR(r12)(r9)
stw r4, VCPU_CR(r9)
/* Restore R1/R2 so we can handle faults */
ld r1, HSTATE_HOST_R1(r13)
ld r2, PACATOC(r13)
mfspr r10, SPRN_SRR0
mfspr r11, SPRN_SRR1
std r10, VCPU_SRR0(r9)
std r11, VCPU_SRR1(r9)
andi. r0, r12, 2 /* need to read HSRR0/1? */
beq 1f
mfspr r10, SPRN_HSRR0
mfspr r11, SPRN_HSRR1
clrrdi r12, r12, 2
1: std r10, VCPU_PC(r9)
std r11, VCPU_MSR(r9)
GET_SCRATCH0(r3)
mflr r4
std r3, VCPU_GPR(r13)(r9)
std r4, VCPU_LR(r9)
/* Unset guest mode */
li r0, KVM_GUEST_MODE_NONE
stb r0, HSTATE_IN_GUEST(r13)
stw r12,VCPU_TRAP(r9)
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
/* Save HEIR (HV emulation assist reg) in last_inst
if this is an HEI (HV emulation interrupt, e40) */
li r3,KVM_INST_FETCH_FAILED
BEGIN_FTR_SECTION
cmpwi r12,BOOK3S_INTERRUPT_H_EMUL_ASSIST
bne 11f
mfspr r3,SPRN_HEIR
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
11: stw r3,VCPU_LAST_INST(r9)
/* these are volatile across C function calls */
mfctr r3
mfxer r4
std r3, VCPU_CTR(r9)
stw r4, VCPU_XER(r9)
BEGIN_FTR_SECTION
/* If this is a page table miss then see if it's theirs or ours */
cmpwi r12, BOOK3S_INTERRUPT_H_DATA_STORAGE
beq kvmppc_hdsi
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:38:05 +07:00
cmpwi r12, BOOK3S_INTERRUPT_H_INST_STORAGE
beq kvmppc_hisi
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* See if this is a leftover HDEC interrupt */
cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER
bne 2f
mfspr r3,SPRN_HDEC
cmpwi r3,0
bge ignore_hdec
2:
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
/* See if this is an hcall we can handle in real mode */
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
cmpwi r12,BOOK3S_INTERRUPT_SYSCALL
beq hcall_try_real_mode
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Check for mediated interrupts (could be done earlier really ...) */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
cmpwi r12,BOOK3S_INTERRUPT_EXTERNAL
bne+ 1f
andi. r0,r11,MSR_EE
beq 1f
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
mfspr r5,SPRN_LPCR
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
andi. r0,r5,LPCR_MER
bne bounce_ext_interrupt
1:
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
nohpte_cont:
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
hcall_real_cont: /* r9 = vcpu, r12 = trap, r13 = paca */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Save DEC */
mfspr r5,SPRN_DEC
mftb r6
extsw r5,r5
add r5,r5,r6
std r5,VCPU_DEC_EXPIRES(r9)
/* Save more register state */
mfdar r6
mfdsisr r7
std r6, VCPU_DAR(r9)
stw r7, VCPU_DSISR(r9)
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
/* don't overwrite fault_dar/fault_dsisr if HDSI */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
cmpwi r12,BOOK3S_INTERRUPT_H_DATA_STORAGE
beq 6f
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
std r6, VCPU_FAULT_DAR(r9)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
stw r7, VCPU_FAULT_DSISR(r9)
/* Save guest CTRL register, set runlatch to 1 */
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
6: mfspr r6,SPRN_CTRLF
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
stw r6,VCPU_CTRL(r9)
andi. r0,r6,1
bne 4f
ori r6,r6,1
mtspr SPRN_CTRLT,r6
4:
/* Read the guest SLB and save it away */
lwz r0,VCPU_SLB_NR(r9) /* number of entries in SLB */
mtctr r0
li r6,0
addi r7,r9,VCPU_SLB
li r5,0
1: slbmfee r8,r6
andis. r0,r8,SLB_ESID_V@h
beq 2f
add r8,r8,r6 /* put index in */
slbmfev r3,r6
std r8,VCPU_SLB_E(r7)
std r3,VCPU_SLB_V(r7)
addi r7,r7,VCPU_SLB_SIZE
addi r5,r5,1
2: addi r6,r6,1
bdnz 1b
stw r5,VCPU_SLB_MAX(r9)
/*
* Save the guest PURR/SPURR
*/
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mfspr r5,SPRN_PURR
mfspr r6,SPRN_SPURR
ld r7,VCPU_PURR(r9)
ld r8,VCPU_SPURR(r9)
std r5,VCPU_PURR(r9)
std r6,VCPU_SPURR(r9)
subf r5,r7,r5
subf r6,r8,r6
/*
* Restore host PURR/SPURR and add guest times
* so that the time in the guest gets accounted.
*/
ld r3,HSTATE_PURR(r13)
ld r4,HSTATE_SPURR(r13)
add r3,r3,r5
add r4,r4,r6
mtspr SPRN_PURR,r3
mtspr SPRN_SPURR,r4
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Clear out SLB */
li r5,0
slbmte r5,r5
slbia
ptesync
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
hdec_soon: /* r9 = vcpu, r12 = trap, r13 = paca */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
b 32f
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
/*
* POWER7 guest -> host partition switch code.
* We don't have to lock against tlbies but we do
* have to coordinate the hardware threads.
*/
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
/* Increment the threads-exiting-guest count in the 0xff00
bits of vcore->entry_exit_count */
lwsync
ld r5,HSTATE_KVM_VCORE(r13)
addi r6,r5,VCORE_ENTRY_EXIT
41: lwarx r3,0,r6
addi r0,r3,0x100
stwcx. r0,0,r6
bne 41b
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
lwsync
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
/*
* At this point we have an interrupt that we have to pass
* up to the kernel or qemu; we can't handle it in real mode.
* Thus we have to do a partition switch, so we have to
* collect the other threads, if we are the first thread
* to take an interrupt. To do this, we set the HDEC to 0,
* which causes an HDEC interrupt in all threads within 2ns
* because the HDEC register is shared between all 4 threads.
* However, we don't need to bother if this is an HDEC
* interrupt, since the other threads will already be on their
* way here in that case.
*/
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
cmpwi r3,0x100 /* Are we the first here? */
bge 43f
cmpwi r3,1 /* Are any other threads in the guest? */
ble 43f
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
cmpwi r12,BOOK3S_INTERRUPT_HV_DECREMENTER
beq 40f
li r0,0
mtspr SPRN_HDEC,r0
40:
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
/*
* Send an IPI to any napping threads, since an HDEC interrupt
* doesn't wake CPUs up from nap.
*/
lwz r3,VCORE_NAPPING_THREADS(r5)
lwz r4,VCPU_PTID(r9)
li r0,1
sldi r0,r0,r4
andc. r3,r3,r0 /* no sense IPI'ing ourselves */
beq 43f
mulli r4,r4,PACA_SIZE /* get paca for thread 0 */
subf r6,r4,r13
42: andi. r0,r3,1
beq 44f
ld r8,HSTATE_XICS_PHYS(r6) /* get thread's XICS reg addr */
li r0,IPI_PRIORITY
li r7,XICS_QIRR
stbcix r0,r7,r8 /* trigger the IPI */
44: srdi. r3,r3,1
addi r6,r6,PACA_SIZE
bne 42b
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
/* Secondary threads wait for primary to do partition switch */
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
43: ld r4,VCPU_KVM(r9) /* pointer to struct kvm */
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
ld r5,HSTATE_KVM_VCORE(r13)
lwz r3,VCPU_PTID(r9)
cmpwi r3,0
beq 15f
HMT_LOW
13: lbz r3,VCORE_IN_GUEST(r5)
cmpwi r3,0
bne 13b
HMT_MEDIUM
b 16f
/* Primary thread waits for all the secondaries to exit guest */
15: lwz r3,VCORE_ENTRY_EXIT(r5)
srwi r0,r3,8
clrldi r3,r3,56
cmpw r3,r0
bne 15b
isync
/* Primary thread switches back to host partition */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
ld r6,KVM_HOST_SDR1(r4)
lwz r7,KVM_HOST_LPID(r4)
li r8,LPID_RSVD /* switch to reserved LPID */
mtspr SPRN_LPID,r8
ptesync
mtspr SPRN_SDR1,r6 /* switch to partition page table */
mtspr SPRN_LPID,r7
isync
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
li r0,0
stb r0,VCORE_IN_GUEST(r5)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
lis r8,0x7fff /* MAX_INT@h */
mtspr SPRN_HDEC,r8
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
16: ld r8,KVM_HOST_LPCR(r4)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mtspr SPRN_LPCR,r8
isync
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
b 33f
/*
* PPC970 guest -> host partition switch code.
* We have to lock against concurrent tlbies, and
* we have to flush the whole TLB.
*/
32: ld r4,VCPU_KVM(r9) /* pointer to struct kvm */
/* Take the guest's tlbie_lock */
lwz r8,PACA_LOCK_TOKEN(r13)
addi r3,r4,KVM_TLBIE_LOCK
24: lwarx r0,0,r3
cmpwi r0,0
bne 24b
stwcx. r8,0,r3
bne 24b
isync
ld r7,KVM_HOST_LPCR(r4) /* use kvm->arch.host_lpcr for HID4 */
li r0,0x18f
rotldi r0,r0,HID4_LPID5_SH /* all lpid bits in HID4 = 1 */
or r0,r7,r0
ptesync
sync
mtspr SPRN_HID4,r0 /* switch to reserved LPID */
isync
li r0,0
stw r0,0(r3) /* drop guest tlbie_lock */
/* invalidate the whole TLB */
li r0,256
mtctr r0
li r6,0
25: tlbiel r6
addi r6,r6,0x1000
bdnz 25b
ptesync
/* take native_tlbie_lock */
ld r3,toc_tlbie_lock@toc(2)
24: lwarx r0,0,r3
cmpwi r0,0
bne 24b
stwcx. r8,0,r3
bne 24b
isync
ld r6,KVM_HOST_SDR1(r4)
mtspr SPRN_SDR1,r6 /* switch to host page table */
/* Set up host HID4 value */
sync
mtspr SPRN_HID4,r7
isync
li r0,0
stw r0,0(r3) /* drop native_tlbie_lock */
lis r8,0x7fff /* MAX_INT@h */
mtspr SPRN_HDEC,r8
/* Disable HDEC interrupts */
mfspr r0,SPRN_HID0
li r3,0
rldimi r0,r3, HID0_HDICE_SH, 64-HID0_HDICE_SH-1
sync
mtspr SPRN_HID0,r0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
mfspr r0,SPRN_HID0
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* load host SLB entries */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
33: ld r8,PACA_SLBSHADOWPTR(r13)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
.rept SLB_NUM_BOLTED
ld r5,SLBSHADOW_SAVEAREA(r8)
ld r6,SLBSHADOW_SAVEAREA+8(r8)
andis. r7,r5,SLB_ESID_V@h
beq 1f
slbmte r6,r5
1: addi r8,r8,16
.endr
/* Save and reset AMR and UAMOR before turning on the MMU */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mfspr r5,SPRN_AMR
mfspr r6,SPRN_UAMOR
std r5,VCPU_AMR(r9)
std r6,VCPU_UAMOR(r9)
li r6,0
mtspr SPRN_AMR,r6
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Switch DSCR back to host value */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mfspr r8, SPRN_DSCR
ld r7, HSTATE_DSCR(r13)
std r8, VCPU_DSCR(r7)
mtspr SPRN_DSCR, r7
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/* Save non-volatile GPRs */
std r14, VCPU_GPR(r14)(r9)
std r15, VCPU_GPR(r15)(r9)
std r16, VCPU_GPR(r16)(r9)
std r17, VCPU_GPR(r17)(r9)
std r18, VCPU_GPR(r18)(r9)
std r19, VCPU_GPR(r19)(r9)
std r20, VCPU_GPR(r20)(r9)
std r21, VCPU_GPR(r21)(r9)
std r22, VCPU_GPR(r22)(r9)
std r23, VCPU_GPR(r23)(r9)
std r24, VCPU_GPR(r24)(r9)
std r25, VCPU_GPR(r25)(r9)
std r26, VCPU_GPR(r26)(r9)
std r27, VCPU_GPR(r27)(r9)
std r28, VCPU_GPR(r28)(r9)
std r29, VCPU_GPR(r29)(r9)
std r30, VCPU_GPR(r30)(r9)
std r31, VCPU_GPR(r31)(r9)
/* Save SPRGs */
mfspr r3, SPRN_SPRG0
mfspr r4, SPRN_SPRG1
mfspr r5, SPRN_SPRG2
mfspr r6, SPRN_SPRG3
std r3, VCPU_SPRG0(r9)
std r4, VCPU_SPRG1(r9)
std r5, VCPU_SPRG2(r9)
std r6, VCPU_SPRG3(r9)
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
/* save FP state */
mr r3, r9
bl .kvmppc_save_fp
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
/* Increment yield count if they have a VPA */
ld r8, VCPU_VPA(r9) /* do they have a VPA? */
cmpdi r8, 0
beq 25f
lwz r3, LPPACA_YIELDCOUNT(r8)
addi r3, r3, 1
stw r3, LPPACA_YIELDCOUNT(r8)
25:
/* Save PMU registers if requested */
/* r8 and cr0.eq are live here */
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
li r3, 1
sldi r3, r3, 31 /* MMCR0_FC (freeze counters) bit */
mfspr r4, SPRN_MMCR0 /* save MMCR0 */
mtspr SPRN_MMCR0, r3 /* freeze all counters, disable ints */
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
mfspr r6, SPRN_MMCRA
BEGIN_FTR_SECTION
/* On P7, clear MMCRA in order to disable SDAR updates */
li r7, 0
mtspr SPRN_MMCRA, r7
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
isync
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
beq 21f /* if no VPA, save PMU stuff anyway */
lbz r7, LPPACA_PMCINUSE(r8)
cmpwi r7, 0 /* did they ask for PMU stuff to be saved? */
bne 21f
std r3, VCPU_MMCR(r9) /* if not, set saved MMCR0 to FC */
b 22f
21: mfspr r5, SPRN_MMCR1
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
std r4, VCPU_MMCR(r9)
std r5, VCPU_MMCR + 8(r9)
std r6, VCPU_MMCR + 16(r9)
mfspr r3, SPRN_PMC1
mfspr r4, SPRN_PMC2
mfspr r5, SPRN_PMC3
mfspr r6, SPRN_PMC4
mfspr r7, SPRN_PMC5
mfspr r8, SPRN_PMC6
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
mfspr r10, SPRN_PMC7
mfspr r11, SPRN_PMC8
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
stw r3, VCPU_PMC(r9)
stw r4, VCPU_PMC + 4(r9)
stw r5, VCPU_PMC + 8(r9)
stw r6, VCPU_PMC + 12(r9)
stw r7, VCPU_PMC + 16(r9)
stw r8, VCPU_PMC + 20(r9)
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
stw r10, VCPU_PMC + 24(r9)
stw r11, VCPU_PMC + 28(r9)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
22:
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
/* Secondary threads go off to take a nap on POWER7 */
BEGIN_FTR_SECTION
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
lwz r0,VCPU_PTID(r9)
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
cmpwi r0,0
bne secondary_nap
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_206)
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
/* Restore host DABR and DABRX */
ld r5,HSTATE_DABR(r13)
li r6,7
mtspr SPRN_DABR,r5
mtspr SPRN_DABRX,r6
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/*
* Reload DEC. HDEC interrupts were disabled when
* we reloaded the host's LPCR value.
*/
ld r3, HSTATE_DECEXP(r13)
mftb r4
subf r4, r4, r3
mtspr SPRN_DEC, r4
/* Reload the host's PMU registers */
ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */
lbz r4, LPPACA_PMCINUSE(r3)
cmpwi r4, 0
beq 23f /* skip if not */
lwz r3, HSTATE_PMC(r13)
lwz r4, HSTATE_PMC + 4(r13)
lwz r5, HSTATE_PMC + 8(r13)
lwz r6, HSTATE_PMC + 12(r13)
lwz r8, HSTATE_PMC + 16(r13)
lwz r9, HSTATE_PMC + 20(r13)
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
lwz r10, HSTATE_PMC + 24(r13)
lwz r11, HSTATE_PMC + 28(r13)
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mtspr SPRN_PMC1, r3
mtspr SPRN_PMC2, r4
mtspr SPRN_PMC3, r5
mtspr SPRN_PMC4, r6
mtspr SPRN_PMC5, r8
mtspr SPRN_PMC6, r9
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
BEGIN_FTR_SECTION
mtspr SPRN_PMC7, r10
mtspr SPRN_PMC8, r11
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
ld r3, HSTATE_MMCR(r13)
ld r4, HSTATE_MMCR + 8(r13)
ld r5, HSTATE_MMCR + 16(r13)
mtspr SPRN_MMCR1, r4
mtspr SPRN_MMCRA, r5
mtspr SPRN_MMCR0, r3
isync
23:
/*
* For external and machine check interrupts, we need
* to call the Linux handler to process the interrupt.
* We do that by jumping to the interrupt vector address
* which we have in r12. The [h]rfid at the end of the
* handler will return to the book3s_hv_interrupts.S code.
* For other interrupts we do the rfid to get back
* to the book3s_interrupts.S code here.
*/
ld r8, HSTATE_VMHANDLER(r13)
ld r7, HSTATE_HOST_MSR(r13)
cmpwi r12, BOOK3S_INTERRUPT_EXTERNAL
beq 11f
cmpwi r12, BOOK3S_INTERRUPT_MACHINE_CHECK
/* RFI into the highmem handler, or branch to interrupt handler */
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
12: mfmsr r6
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mtctr r12
li r0, MSR_RI
andc r6, r6, r0
mtmsrd r6, 1 /* Clear RI in MSR */
mtsrr0 r8
mtsrr1 r7
beqctr
RFI
KVM: PPC: book3s_hv: Add support for PPC970-family processors This adds support for running KVM guests in supervisor mode on those PPC970 processors that have a usable hypervisor mode. Unfortunately, Apple G5 machines have supervisor mode disabled (MSR[HV] is forced to 1), but the YDL PowerStation does have a usable hypervisor mode. There are several differences between the PPC970 and POWER7 in how guests are managed. These differences are accommodated using the CPU_FTR_ARCH_201 (PPC970) and CPU_FTR_ARCH_206 (POWER7) CPU feature bits. Notably, on PPC970: * The LPCR, LPID or RMOR registers don't exist, and the functions of those registers are provided by bits in HID4 and one bit in HID0. * External interrupts can be directed to the hypervisor, but unlike POWER7 they are masked by MSR[EE] in non-hypervisor modes and use SRR0/1 not HSRR0/1. * There is no virtual RMA (VRMA) mode; the guest must use an RMO (real mode offset) area. * The TLB entries are not tagged with the LPID, so it is necessary to flush the whole TLB on partition switch. Furthermore, when switching partitions we have to ensure that no other CPU is executing the tlbie or tlbsync instructions in either the old or the new partition, otherwise undefined behaviour can occur. * The PMU has 8 counters (PMC registers) rather than 6. * The DSCR, PURR, SPURR, AMR, AMOR, UAMOR registers don't exist. * The SLB has 64 entries rather than 32. * There is no mediated external interrupt facility, so if we switch to a guest that has a virtual external interrupt pending but the guest has MSR[EE] = 0, we have to arrange to have an interrupt pending for it so that we can get control back once it re-enables interrupts. We do that by sending ourselves an IPI with smp_send_reschedule after hard-disabling interrupts. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:40:08 +07:00
11:
BEGIN_FTR_SECTION
b 12b
END_FTR_SECTION_IFSET(CPU_FTR_ARCH_201)
mtspr SPRN_HSRR0, r8
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
mtspr SPRN_HSRR1, r7
ba 0x500
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
/*
* Check whether an HDSI is an HPTE not found fault or something else.
* If it is an HPTE not found fault that is due to the guest accessing
* a page that they have mapped but which we have paged out, then
* we continue on with the guest exit path. In all other cases,
* reflect the HDSI to the guest as a DSI.
*/
kvmppc_hdsi:
mfspr r4, SPRN_HDAR
mfspr r6, SPRN_HDSISR
KVM: PPC: Allow for read-only pages backing a Book3S HV guest With this, if a guest does an H_ENTER with a read/write HPTE on a page which is currently read-only, we make the actual HPTE inserted be a read-only version of the HPTE. We now intercept protection faults as well as HPTE not found faults, and for a protection fault we work out whether it should be reflected to the guest (e.g. because the guest HPTE didn't allow write access to usermode) or handled by switching to kernel context and calling kvmppc_book3s_hv_page_fault, which will then request write access to the page and update the actual HPTE. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:38:51 +07:00
/* HPTE not found fault or protection fault? */
andis. r0, r6, (DSISR_NOHPTE | DSISR_PROTFAULT)@h
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
beq 1f /* if not, send it to the guest */
andi. r0, r11, MSR_DR /* data relocation enabled? */
beq 3f
clrrdi r0, r4, 28
PPC_SLBFEE_DOT(r5, r0) /* if so, look up SLB */
bne 1f /* if no SLB entry found */
4: std r4, VCPU_FAULT_DAR(r9)
stw r6, VCPU_FAULT_DSISR(r9)
/* Search the hash table. */
mr r3, r9 /* vcpu pointer */
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:38:05 +07:00
li r7, 1 /* data fault */
KVM: PPC: Implement MMIO emulation support for Book3S HV guests This provides the low-level support for MMIO emulation in Book3S HV guests. When the guest tries to map a page which is not covered by any memslot, that page is taken to be an MMIO emulation page. Instead of inserting a valid HPTE, we insert an HPTE that has the valid bit clear but another hypervisor software-use bit set, which we call HPTE_V_ABSENT, to indicate that this is an absent page. An absent page is treated much like a valid page as far as guest hcalls (H_ENTER, H_REMOVE, H_READ etc.) are concerned, except of course that an absent HPTE doesn't need to be invalidated with tlbie since it was never valid as far as the hardware is concerned. When the guest accesses a page for which there is an absent HPTE, it will take a hypervisor data storage interrupt (HDSI) since we now set the VPM1 bit in the LPCR. Our HDSI handler for HPTE-not-present faults looks up the hash table and if it finds an absent HPTE mapping the requested virtual address, will switch to kernel mode and handle the fault in kvmppc_book3s_hv_page_fault(), which at present just calls kvmppc_hv_emulate_mmio() to set up the MMIO emulation. This is based on an earlier patch by Benjamin Herrenschmidt, but since heavily reworked. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:36:37 +07:00
bl .kvmppc_hpte_hv_fault
ld r9, HSTATE_KVM_VCPU(r13)
ld r10, VCPU_PC(r9)
ld r11, VCPU_MSR(r9)
li r12, BOOK3S_INTERRUPT_H_DATA_STORAGE
cmpdi r3, 0 /* retry the instruction */
beq 6f
cmpdi r3, -1 /* handle in kernel mode */
beq nohpte_cont
cmpdi r3, -2 /* MMIO emulation; need instr word */
beq 2f
/* Synthesize a DSI for the guest */
ld r4, VCPU_FAULT_DAR(r9)
mr r6, r3
1: mtspr SPRN_DAR, r4
mtspr SPRN_DSISR, r6
mtspr SPRN_SRR0, r10
mtspr SPRN_SRR1, r11
li r10, BOOK3S_INTERRUPT_DATA_STORAGE
li r11, (MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
rotldi r11, r11, 63
6: ld r7, VCPU_CTR(r9)
lwz r8, VCPU_XER(r9)
mtctr r7
mtxer r8
mr r4, r9
b fast_guest_return
3: ld r5, VCPU_KVM(r9) /* not relocated, use VRMA */
ld r5, KVM_VRMA_SLB_V(r5)
b 4b
/* If this is for emulated MMIO, load the instruction word */
2: li r8, KVM_INST_FETCH_FAILED /* In case lwz faults */
/* Set guest mode to 'jump over instruction' so if lwz faults
* we'll just continue at the next IP. */
li r0, KVM_GUEST_MODE_SKIP
stb r0, HSTATE_IN_GUEST(r13)
/* Do the access with MSR:DR enabled */
mfmsr r3
ori r4, r3, MSR_DR /* Enable paging for data */
mtmsrd r4
lwz r8, 0(r10)
mtmsrd r3
/* Store the result */
stw r8, VCPU_LAST_INST(r9)
/* Unset guest mode. */
li r0, KVM_GUEST_MODE_NONE
stb r0, HSTATE_IN_GUEST(r13)
b nohpte_cont
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
KVM: PPC: Implement MMU notifiers for Book3S HV guests This adds the infrastructure to enable us to page out pages underneath a Book3S HV guest, on processors that support virtualized partition memory, that is, POWER7. Instead of pinning all the guest's pages, we now look in the host userspace Linux page tables to find the mapping for a given guest page. Then, if the userspace Linux PTE gets invalidated, kvm_unmap_hva() gets called for that address, and we replace all the guest HPTEs that refer to that page with absent HPTEs, i.e. ones with the valid bit clear and the HPTE_V_ABSENT bit set, which will cause an HDSI when the guest tries to access them. Finally, the page fault handler is extended to reinstantiate the guest HPTE when the guest tries to access a page which has been paged out. Since we can't intercept the guest DSI and ISI interrupts on PPC970, we still have to pin all the guest pages on PPC970. We have a new flag, kvm->arch.using_mmu_notifiers, that indicates whether we can page guest pages out. If it is not set, the MMU notifier callbacks do nothing and everything operates as before. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-12 19:38:05 +07:00
/*
* Similarly for an HISI, reflect it to the guest as an ISI unless
* it is an HPTE not found fault for a page that we have paged out.
*/
kvmppc_hisi:
andis. r0, r11, SRR1_ISI_NOPT@h
beq 1f
andi. r0, r11, MSR_IR /* instruction relocation enabled? */
beq 3f
clrrdi r0, r10, 28
PPC_SLBFEE_DOT(r5, r0) /* if so, look up SLB */
bne 1f /* if no SLB entry found */
4:
/* Search the hash table. */
mr r3, r9 /* vcpu pointer */
mr r4, r10
mr r6, r11
li r7, 0 /* instruction fault */
bl .kvmppc_hpte_hv_fault
ld r9, HSTATE_KVM_VCPU(r13)
ld r10, VCPU_PC(r9)
ld r11, VCPU_MSR(r9)
li r12, BOOK3S_INTERRUPT_H_INST_STORAGE
cmpdi r3, 0 /* retry the instruction */
beq 6f
cmpdi r3, -1 /* handle in kernel mode */
beq nohpte_cont
/* Synthesize an ISI for the guest */
mr r11, r3
1: mtspr SPRN_SRR0, r10
mtspr SPRN_SRR1, r11
li r10, BOOK3S_INTERRUPT_INST_STORAGE
li r11, (MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
rotldi r11, r11, 63
6: ld r7, VCPU_CTR(r9)
lwz r8, VCPU_XER(r9)
mtctr r7
mtxer r8
mr r4, r9
b fast_guest_return
3: ld r6, VCPU_KVM(r9) /* not relocated, use VRMA */
ld r5, KVM_VRMA_SLB_V(r6)
b 4b
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
/*
* Try to handle an hcall in real mode.
* Returns to the guest if we handle it, or continues on up to
* the kernel if we can't (i.e. if we don't have a handler for
* it, or if the handler returns H_TOO_HARD).
*/
.globl hcall_try_real_mode
hcall_try_real_mode:
ld r3,VCPU_GPR(r3)(r9)
andi. r0,r11,MSR_PR
bne hcall_real_cont
clrrdi r3,r3,2
cmpldi r3,hcall_real_table_end - hcall_real_table
bge hcall_real_cont
LOAD_REG_ADDR(r4, hcall_real_table)
lwzx r3,r3,r4
cmpwi r3,0
beq hcall_real_cont
add r3,r3,r4
mtctr r3
mr r3,r9 /* get vcpu pointer */
ld r4,VCPU_GPR(r4)(r9)
bctrl
cmpdi r3,H_TOO_HARD
beq hcall_real_fallback
ld r4,HSTATE_KVM_VCPU(r13)
std r3,VCPU_GPR(r3)(r4)
ld r10,VCPU_PC(r4)
ld r11,VCPU_MSR(r4)
b fast_guest_return
/* We've attempted a real mode hcall, but it's punted it back
* to userspace. We need to restore some clobbered volatiles
* before resuming the pass-it-to-qemu path */
hcall_real_fallback:
li r12,BOOK3S_INTERRUPT_SYSCALL
ld r9, HSTATE_KVM_VCPU(r13)
b hcall_real_cont
.globl hcall_real_table
hcall_real_table:
.long 0 /* 0 - unused */
.long .kvmppc_h_remove - hcall_real_table
.long .kvmppc_h_enter - hcall_real_table
.long .kvmppc_h_read - hcall_real_table
.long 0 /* 0x10 - H_CLEAR_MOD */
.long 0 /* 0x14 - H_CLEAR_REF */
.long .kvmppc_h_protect - hcall_real_table
.long 0 /* 0x1c - H_GET_TCE */
KVM: PPC: Accelerate H_PUT_TCE by implementing it in real mode This improves I/O performance for guests using the PAPR paravirtualization interface by making the H_PUT_TCE hcall faster, by implementing it in real mode. H_PUT_TCE is used for updating virtual IOMMU tables, and is used both for virtual I/O and for real I/O in the PAPR interface. Since this moves the IOMMU tables into the kernel, we define a new KVM_CREATE_SPAPR_TCE ioctl to allow qemu to create the tables. The ioctl returns a file descriptor which can be used to mmap the newly created table. The qemu driver models use them in the same way as userspace managed tables, but they can be updated directly by the guest with a real-mode H_PUT_TCE implementation, reducing the number of host/guest context switches during guest IO. There are certain circumstances where it is useful for userland qemu to write to the TCE table even if the kernel H_PUT_TCE path is used most of the time. Specifically, allowing this will avoid awkwardness when we need to reset the table. More importantly, we will in the future need to write the table in order to restore its state after a checkpoint resume or migration. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:41 +07:00
.long .kvmppc_h_put_tce - hcall_real_table
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
.long 0 /* 0x24 - H_SET_SPRG0 */
.long .kvmppc_h_set_dabr - hcall_real_table
.long 0 /* 0x2c */
.long 0 /* 0x30 */
.long 0 /* 0x34 */
.long 0 /* 0x38 */
.long 0 /* 0x3c */
.long 0 /* 0x40 */
.long 0 /* 0x44 */
.long 0 /* 0x48 */
.long 0 /* 0x4c */
.long 0 /* 0x50 */
.long 0 /* 0x54 */
.long 0 /* 0x58 */
.long 0 /* 0x5c */
.long 0 /* 0x60 */
.long 0 /* 0x64 */
.long 0 /* 0x68 */
.long 0 /* 0x6c */
.long 0 /* 0x70 */
.long 0 /* 0x74 */
.long 0 /* 0x78 */
.long 0 /* 0x7c */
.long 0 /* 0x80 */
.long 0 /* 0x84 */
.long 0 /* 0x88 */
.long 0 /* 0x8c */
.long 0 /* 0x90 */
.long 0 /* 0x94 */
.long 0 /* 0x98 */
.long 0 /* 0x9c */
.long 0 /* 0xa0 */
.long 0 /* 0xa4 */
.long 0 /* 0xa8 */
.long 0 /* 0xac */
.long 0 /* 0xb0 */
.long 0 /* 0xb4 */
.long 0 /* 0xb8 */
.long 0 /* 0xbc */
.long 0 /* 0xc0 */
.long 0 /* 0xc4 */
.long 0 /* 0xc8 */
.long 0 /* 0xcc */
.long 0 /* 0xd0 */
.long 0 /* 0xd4 */
.long 0 /* 0xd8 */
.long 0 /* 0xdc */
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
.long .kvmppc_h_cede - hcall_real_table
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
.long 0 /* 0xe4 */
.long 0 /* 0xe8 */
.long 0 /* 0xec */
.long 0 /* 0xf0 */
.long 0 /* 0xf4 */
.long 0 /* 0xf8 */
.long 0 /* 0xfc */
.long 0 /* 0x100 */
.long 0 /* 0x104 */
.long 0 /* 0x108 */
.long 0 /* 0x10c */
.long 0 /* 0x110 */
.long 0 /* 0x114 */
.long 0 /* 0x118 */
.long 0 /* 0x11c */
.long 0 /* 0x120 */
.long .kvmppc_h_bulk_remove - hcall_real_table
hcall_real_table_end:
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
ignore_hdec:
mr r4,r9
b fast_guest_return
bounce_ext_interrupt:
mr r4,r9
mtspr SPRN_SRR0,r10
mtspr SPRN_SRR1,r11
li r10,BOOK3S_INTERRUPT_EXTERNAL
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
li r11,(MSR_ME << 1) | 1 /* synthesize MSR_SF | MSR_ME */
rotldi r11,r11,63
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
b fast_guest_return
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
_GLOBAL(kvmppc_h_set_dabr)
std r4,VCPU_DABR(r3)
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
/* Work around P7 bug where DABR can get corrupted on mtspr */
1: mtspr SPRN_DABR,r4
mfspr r5, SPRN_DABR
cmpd r4, r5
bne 1b
isync
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
li r3,0
blr
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
_GLOBAL(kvmppc_h_cede)
ori r11,r11,MSR_EE
std r11,VCPU_MSR(r3)
li r0,1
stb r0,VCPU_CEDED(r3)
sync /* order setting ceded vs. testing prodded */
lbz r5,VCPU_PRODDED(r3)
cmpwi r5,0
bne 1f
li r0,0 /* set trap to 0 to say hcall is handled */
stw r0,VCPU_TRAP(r3)
li r0,H_SUCCESS
std r0,VCPU_GPR(r3)(r3)
BEGIN_FTR_SECTION
b 2f /* just send it up to host on 970 */
END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_206)
/*
* Set our bit in the bitmask of napping threads unless all the
* other threads are already napping, in which case we send this
* up to the host.
*/
ld r5,HSTATE_KVM_VCORE(r13)
lwz r6,VCPU_PTID(r3)
lwz r8,VCORE_ENTRY_EXIT(r5)
clrldi r8,r8,56
li r0,1
sld r0,r0,r6
addi r6,r5,VCORE_NAPPING_THREADS
31: lwarx r4,0,r6
or r4,r4,r0
powerpc/kvm: Fix build with older toolchains Fix KVM build for older toolchains (found with .powerpc64-unknown-linux-gnu-gcc (crosstool-NG-1.8.1) 4.3.2): AS arch/powerpc/kvm/book3s_hv_rmhandlers.o arch/powerpc/kvm/book3s_hv_rmhandlers.S: Assembler messages: arch/powerpc/kvm/book3s_hv_rmhandlers.S:1388: Error: Unrecognized opcode: `popcntw' make[1]: *** [arch/powerpc/kvm/book3s_hv_rmhandlers.o] Error 1 make: *** [_module_arch/powerpc/kvm] Error 2 Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-11-07 20:36:56 +07:00
PPC_POPCNTW(r7,r4)
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
cmpw r7,r8
bge 2f
stwcx. r4,0,r6
bne 31b
li r0,1
stb r0,HSTATE_NAPPING(r13)
/* order napping_threads update vs testing entry_exit_count */
lwsync
mr r4,r3
lwz r7,VCORE_ENTRY_EXIT(r5)
cmpwi r7,0x100
bge 33f /* another thread already exiting */
/*
* Although not specifically required by the architecture, POWER7
* preserves the following registers in nap mode, even if an SMT mode
* switch occurs: SLB entries, PURR, SPURR, AMOR, UAMOR, AMR, SPRG0-3,
* DAR, DSISR, DABR, DABRX, DSCR, PMCx, MMCRx, SIAR, SDAR.
*/
/* Save non-volatile GPRs */
std r14, VCPU_GPR(r14)(r3)
std r15, VCPU_GPR(r15)(r3)
std r16, VCPU_GPR(r16)(r3)
std r17, VCPU_GPR(r17)(r3)
std r18, VCPU_GPR(r18)(r3)
std r19, VCPU_GPR(r19)(r3)
std r20, VCPU_GPR(r20)(r3)
std r21, VCPU_GPR(r21)(r3)
std r22, VCPU_GPR(r22)(r3)
std r23, VCPU_GPR(r23)(r3)
std r24, VCPU_GPR(r24)(r3)
std r25, VCPU_GPR(r25)(r3)
std r26, VCPU_GPR(r26)(r3)
std r27, VCPU_GPR(r27)(r3)
std r28, VCPU_GPR(r28)(r3)
std r29, VCPU_GPR(r29)(r3)
std r30, VCPU_GPR(r30)(r3)
std r31, VCPU_GPR(r31)(r3)
/* save FP state */
bl .kvmppc_save_fp
/*
* Take a nap until a decrementer or external interrupt occurs,
* with PECE1 (wake on decr) and PECE0 (wake on external) set in LPCR
*/
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
li r0,1
stb r0,HSTATE_HWTHREAD_REQ(r13)
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
mfspr r5,SPRN_LPCR
ori r5,r5,LPCR_PECE0 | LPCR_PECE1
mtspr SPRN_LPCR,r5
isync
li r0, 0
std r0, HSTATE_SCRATCH0(r13)
ptesync
ld r0, HSTATE_SCRATCH0(r13)
1: cmpd r0, r0
bne 1b
nap
b .
kvm_end_cede:
/* Woken by external or decrementer interrupt */
ld r1, HSTATE_HOST_R1(r13)
/* load up FP state */
bl kvmppc_load_fp
/* Load NV GPRS */
ld r14, VCPU_GPR(r14)(r4)
ld r15, VCPU_GPR(r15)(r4)
ld r16, VCPU_GPR(r16)(r4)
ld r17, VCPU_GPR(r17)(r4)
ld r18, VCPU_GPR(r18)(r4)
ld r19, VCPU_GPR(r19)(r4)
ld r20, VCPU_GPR(r20)(r4)
ld r21, VCPU_GPR(r21)(r4)
ld r22, VCPU_GPR(r22)(r4)
ld r23, VCPU_GPR(r23)(r4)
ld r24, VCPU_GPR(r24)(r4)
ld r25, VCPU_GPR(r25)(r4)
ld r26, VCPU_GPR(r26)(r4)
ld r27, VCPU_GPR(r27)(r4)
ld r28, VCPU_GPR(r28)(r4)
ld r29, VCPU_GPR(r29)(r4)
ld r30, VCPU_GPR(r30)(r4)
ld r31, VCPU_GPR(r31)(r4)
/* clear our bit in vcore->napping_threads */
33: ld r5,HSTATE_KVM_VCORE(r13)
lwz r3,VCPU_PTID(r4)
li r0,1
sld r0,r0,r3
addi r6,r5,VCORE_NAPPING_THREADS
32: lwarx r7,0,r6
andc r7,r7,r0
stwcx. r7,0,r6
bne 32b
li r0,0
stb r0,HSTATE_NAPPING(r13)
/* see if any other thread is already exiting */
lwz r0,VCORE_ENTRY_EXIT(r5)
cmpwi r0,0x100
blt kvmppc_cede_reentry /* if not go back to guest */
/* some threads are exiting, so go to the guest exit path */
b hcall_real_fallback
/* cede when already previously prodded case */
1: li r0,0
stb r0,VCPU_PRODDED(r3)
sync /* order testing prodded vs. clearing ceded */
stb r0,VCPU_CEDED(r3)
li r3,H_SUCCESS
blr
/* we've ceded but we want to give control to the host */
2: li r3,H_TOO_HARD
blr
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
secondary_too_late:
ld r5,HSTATE_KVM_VCORE(r13)
HMT_LOW
13: lbz r3,VCORE_IN_GUEST(r5)
cmpwi r3,0
bne 13b
HMT_MEDIUM
ld r11,PACA_SLBSHADOWPTR(r13)
.rept SLB_NUM_BOLTED
ld r5,SLBSHADOW_SAVEAREA(r11)
ld r6,SLBSHADOW_SAVEAREA+8(r11)
andis. r7,r5,SLB_ESID_V@h
beq 1f
slbmte r6,r5
1: addi r11,r11,16
.endr
secondary_nap:
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
/* Clear any pending IPI - assume we're a secondary thread */
ld r5, HSTATE_XICS_PHYS(r13)
li r7, XICS_XIRR
lwzcix r3, r5, r7 /* ack any pending interrupt */
rlwinm. r0, r3, 0, 0xffffff /* any pending? */
beq 37f
sync
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
li r0, 0xff
li r6, XICS_QIRR
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
stbcix r0, r5, r6 /* clear the IPI */
stwcix r3, r5, r7 /* EOI it */
37: sync
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
/* increment the nap count and then go to nap mode */
ld r4, HSTATE_KVM_VCORE(r13)
addi r4, r4, VCORE_NAP_COUNT
lwsync /* make previous updates visible */
51: lwarx r3, 0, r4
addi r3, r3, 1
stwcx. r3, 0, r4
bne 51b
KVM: PPC: Book3S HV: Make secondary threads more robust against stray IPIs Currently on POWER7, if we are running the guest on a core and we don't need all the hardware threads, we do nothing to ensure that the unused threads aren't executing in the kernel (other than checking that they are offline). We just assume they're napping and we don't do anything to stop them trying to enter the kernel while the guest is running. This means that a stray IPI can wake up the hardware thread and it will then try to enter the kernel, but since the core is in guest context, it will execute code from the guest in hypervisor mode once it turns the MMU on, which tends to lead to crashes or hangs in the host. This fixes the problem by adding two new one-byte flags in the kvmppc_host_state structure in the PACA which are used to interlock between the primary thread and the unused secondary threads when entering the guest. With these flags, the primary thread can ensure that the unused secondaries are not already in kernel mode (i.e. handling a stray IPI) and then indicate that they should not try to enter the kernel if they do get woken for any reason. Instead they will go into KVM code, find that there is no vcpu to run, acknowledge and clear the IPI and go back to nap mode. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-02-03 07:54:17 +07:00
kvm_no_guest:
li r0, KVM_HWTHREAD_IN_NAP
stb r0, HSTATE_HWTHREAD_STATE(r13)
li r0, 0
std r0, HSTATE_KVM_VCPU(r13)
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
li r3, LPCR_PECE0
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
mfspr r4, SPRN_LPCR
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
rlwimi r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
mtspr SPRN_LPCR, r4
KVM: PPC: Implement H_CEDE hcall for book3s_hv in real-mode code With a KVM guest operating in SMT4 mode (i.e. 4 hardware threads per core), whenever a CPU goes idle, we have to pull all the other hardware threads in the core out of the guest, because the H_CEDE hcall is handled in the kernel. This is inefficient. This adds code to book3s_hv_rmhandlers.S to handle the H_CEDE hcall in real mode. When a guest vcpu does an H_CEDE hcall, we now only exit to the kernel if all the other vcpus in the same core are also idle. Otherwise we mark this vcpu as napping, save state that could be lost in nap mode (mainly GPRs and FPRs), and execute the nap instruction. When the thread wakes up, because of a decrementer or external interrupt, we come back in at kvm_start_guest (from the system reset interrupt vector), find the `napping' flag set in the paca, and go to the resume path. This has some other ramifications. First, when starting a core, we now start all the threads, both those that are immediately runnable and those that are idle. This is so that we don't have to pull all the threads out of the guest when an idle thread gets a decrementer interrupt and wants to start running. In fact the idle threads will all start with the H_CEDE hcall returning; being idle they will just do another H_CEDE immediately and go to nap mode. This required some changes to kvmppc_run_core() and kvmppc_run_vcpu(). These functions have been restructured to make them simpler and clearer. We introduce a level of indirection in the wait queue that gets woken when external and decrementer interrupts get generated for a vcpu, so that we can have the 4 vcpus in a vcore using the same wait queue. We need this because the 4 vcpus are being handled by one thread. Secondly, when we need to exit from the guest to the kernel, we now have to generate an IPI for any napping threads, because an HDEC interrupt doesn't wake up a napping thread. Thirdly, we now need to be able to handle virtual external interrupts and decrementer interrupts becoming pending while a thread is napping, and deliver those interrupts to the guest when the thread wakes. This is done in kvmppc_cede_reentry, just before fast_guest_return. Finally, since we are not using the generic kvm_vcpu_block for book3s_hv, and hence not calling kvm_arch_vcpu_runnable, we can remove the #ifdef from kvm_arch_vcpu_runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-07-23 14:42:46 +07:00
isync
KVM: PPC: Allow book3s_hv guests to use SMT processor modes This lifts the restriction that book3s_hv guests can only run one hardware thread per core, and allows them to use up to 4 threads per core on POWER7. The host still has to run single-threaded. This capability is advertised to qemu through a new KVM_CAP_PPC_SMT capability. The return value of the ioctl querying this capability is the number of vcpus per virtual CPU core (vcore), currently 4. To use this, the host kernel should be booted with all threads active, and then all the secondary threads should be offlined. This will put the secondary threads into nap mode. KVM will then wake them from nap mode and use them for running guest code (while they are still offline). To wake the secondary threads, we send them an IPI using a new xics_wake_cpu() function, implemented in arch/powerpc/sysdev/xics/icp-native.c. In other words, at this stage we assume that the platform has a XICS interrupt controller and we are using icp-native.c to drive it. Since the woken thread will need to acknowledge and clear the IPI, we also export the base physical address of the XICS registers using kvmppc_set_xics_phys() for use in the low-level KVM book3s code. When a vcpu is created, it is assigned to a virtual CPU core. The vcore number is obtained by dividing the vcpu number by the number of threads per core in the host. This number is exported to userspace via the KVM_CAP_PPC_SMT capability. If qemu wishes to run the guest in single-threaded mode, it should make all vcpu numbers be multiples of the number of threads per core. We distinguish three states of a vcpu: runnable (i.e., ready to execute the guest), blocked (that is, idle), and busy in host. We currently implement a policy that the vcore can run only when all its threads are runnable or blocked. This way, if a vcpu needs to execute elsewhere in the kernel or in qemu, it can do so without being starved of CPU by the other vcpus. When a vcore starts to run, it executes in the context of one of the vcpu threads. The other vcpu threads all go to sleep and stay asleep until something happens requiring the vcpu thread to return to qemu, or to wake up to run the vcore (this can happen when another vcpu thread goes from busy in host state to blocked). It can happen that a vcpu goes from blocked to runnable state (e.g. because of an interrupt), and the vcore it belongs to is already running. In that case it can start to run immediately as long as the none of the vcpus in the vcore have started to exit the guest. We send the next free thread in the vcore an IPI to get it to start to execute the guest. It synchronizes with the other threads via the vcore->entry_exit_count field to make sure that it doesn't go into the guest if the other vcpus are exiting by the time that it is ready to actually enter the guest. Note that there is no fixed relationship between the hardware thread number and the vcpu number. Hardware threads are assigned to vcpus as they become runnable, so we will always use the lower-numbered hardware threads in preference to higher-numbered threads if not all the vcpus in the vcore are runnable, regardless of which vcpus are runnable. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:23:08 +07:00
std r0, HSTATE_SCRATCH0(r13)
ptesync
ld r0, HSTATE_SCRATCH0(r13)
1: cmpd r0, r0
bne 1b
nap
b .
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
/*
* Save away FP, VMX and VSX registers.
* r3 = vcpu pointer
KVM: PPC: Handle some PAPR hcalls in the kernel This adds the infrastructure for handling PAPR hcalls in the kernel, either early in the guest exit path while we are still in real mode, or later once the MMU has been turned back on and we are in the full kernel context. The advantage of handling hcalls in real mode if possible is that we avoid two partition switches -- and this will become more important when we support SMT4 guests, since a partition switch means we have to pull all of the threads in the core out of the guest. The disadvantage is that we can only access the kernel linear mapping, not anything vmalloced or ioremapped, since the MMU is off. This also adds code to handle the following hcalls in real mode: H_ENTER Add an HPTE to the hashed page table H_REMOVE Remove an HPTE from the hashed page table H_READ Read HPTEs from the hashed page table H_PROTECT Change the protection bits in an HPTE H_BULK_REMOVE Remove up to 4 HPTEs from the hashed page table H_SET_DABR Set the data address breakpoint register Plus code to handle the following hcalls in the kernel: H_CEDE Idle the vcpu until an interrupt or H_PROD hcall arrives H_PROD Wake up a ceded vcpu H_REGISTER_VPA Register a virtual processor area (VPA) The code that runs in real mode has to be in the base kernel, not in the module, if KVM is compiled as a module. The real-mode code can only access the kernel linear mapping, not vmalloc or ioremap space. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:22:05 +07:00
*/
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
_GLOBAL(kvmppc_save_fp)
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
mfmsr r5
ori r8,r5,MSR_FP
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
oris r8,r8,MSR_VEC@h
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
oris r8,r8,MSR_VSX@h
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
mtmsrd r8
isync
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
reg = 0
.rept 32
li r6,reg*16+VCPU_VSRS
powerpc/kvm: Fix build errors with older toolchains On a box with gcc 4.3.2, I see errors like: arch/powerpc/kvm/book3s_hv_rmhandlers.S:1254: Error: Unrecognized opcode: stxvd2x arch/powerpc/kvm/book3s_hv_rmhandlers.S:1316: Error: Unrecognized opcode: lxvd2x Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-08-03 15:55:54 +07:00
STXVD2X(reg,r6,r3)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
reg = reg + 1
.endr
FTR_SECTION_ELSE
#endif
reg = 0
.rept 32
stfd reg,reg*8+VCPU_FPRS(r3)
reg = reg + 1
.endr
#ifdef CONFIG_VSX
ALT_FTR_SECTION_END_IFSET(CPU_FTR_VSX)
#endif
mffs fr0
stfd fr0,VCPU_FPSCR(r3)
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
reg = 0
.rept 32
li r6,reg*16+VCPU_VRS
stvx reg,r6,r3
reg = reg + 1
.endr
mfvscr vr0
li r6,VCPU_VSCR
stvx vr0,r6,r3
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
mfspr r6,SPRN_VRSAVE
stw r6,VCPU_VRSAVE(r3)
KVM: PPC: Work around POWER7 DABR corruption problem It turns out that on POWER7, writing to the DABR can cause a corrupted value to be written if the PMU is active and updating SDAR in continuous sampling mode. To work around this, we make sure that the PMU is inactive and SDAR updates are disabled (via MMCRA) when we are context-switching DABR. When the guest sets DABR via the H_SET_DABR hypercall, we use a slightly different workaround, which is to read back the DABR and write it again if it got corrupted. While we are at it, make it consistent that the saving and restoring of the guest's non-volatile GPRs and the FPRs are done with the guest setup of the PMU active. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-02 08:38:23 +07:00
mtmsrd r5
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
isync
blr
/*
* Load up FP, VMX and VSX registers
* r4 = vcpu pointer
*/
.globl kvmppc_load_fp
kvmppc_load_fp:
mfmsr r9
ori r8,r9,MSR_FP
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
oris r8,r8,MSR_VEC@h
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
oris r8,r8,MSR_VSX@h
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
mtmsrd r8
isync
lfd fr0,VCPU_FPSCR(r4)
MTFSF_L(fr0)
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
reg = 0
.rept 32
li r7,reg*16+VCPU_VSRS
powerpc/kvm: Fix build errors with older toolchains On a box with gcc 4.3.2, I see errors like: arch/powerpc/kvm/book3s_hv_rmhandlers.S:1254: Error: Unrecognized opcode: stxvd2x arch/powerpc/kvm/book3s_hv_rmhandlers.S:1316: Error: Unrecognized opcode: lxvd2x Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-08-03 15:55:54 +07:00
LXVD2X(reg,r7,r4)
KVM: PPC: Add support for Book3S processors in hypervisor mode This adds support for KVM running on 64-bit Book 3S processors, specifically POWER7, in hypervisor mode. Using hypervisor mode means that the guest can use the processor's supervisor mode. That means that the guest can execute privileged instructions and access privileged registers itself without trapping to the host. This gives excellent performance, but does mean that KVM cannot emulate a processor architecture other than the one that the hardware implements. This code assumes that the guest is running paravirtualized using the PAPR (Power Architecture Platform Requirements) interface, which is the interface that IBM's PowerVM hypervisor uses. That means that existing Linux distributions that run on IBM pSeries machines will also run under KVM without modification. In order to communicate the PAPR hypercalls to qemu, this adds a new KVM_EXIT_PAPR_HCALL exit code to include/linux/kvm.h. Currently the choice between book3s_hv support and book3s_pr support (i.e. the existing code, which runs the guest in user mode) has to be made at kernel configuration time, so a given kernel binary can only do one or the other. This new book3s_hv code doesn't support MMIO emulation at present. Since we are running paravirtualized guests, this isn't a serious restriction. With the guest running in supervisor mode, most exceptions go straight to the guest. We will never get data or instruction storage or segment interrupts, alignment interrupts, decrementer interrupts, program interrupts, single-step interrupts, etc., coming to the hypervisor from the guest. Therefore this introduces a new KVMTEST_NONHV macro for the exception entry path so that we don't have to do the KVM test on entry to those exception handlers. We do however get hypervisor decrementer, hypervisor data storage, hypervisor instruction storage, and hypervisor emulation assist interrupts, so we have to handle those. In hypervisor mode, real-mode accesses can access all of RAM, not just a limited amount. Therefore we put all the guest state in the vcpu.arch and use the shadow_vcpu in the PACA only for temporary scratch space. We allocate the vcpu with kzalloc rather than vzalloc, and we don't use anything in the kvmppc_vcpu_book3s struct, so we don't allocate it. We don't have a shared page with the guest, but we still need a kvm_vcpu_arch_shared struct to store the values of various registers, so we include one in the vcpu_arch struct. The POWER7 processor has a restriction that all threads in a core have to be in the same partition. MMU-on kernel code counts as a partition (partition 0), so we have to do a partition switch on every entry to and exit from the guest. At present we require the host and guest to run in single-thread mode because of this hardware restriction. This code allocates a hashed page table for the guest and initializes it with HPTEs for the guest's Virtual Real Memory Area (VRMA). We require that the guest memory is allocated using 16MB huge pages, in order to simplify the low-level memory management. This also means that we can get away without tracking paging activity in the host for now, since huge pages can't be paged or swapped. This also adds a few new exports needed by the book3s_hv code. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2011-06-29 07:21:34 +07:00
reg = reg + 1
.endr
FTR_SECTION_ELSE
#endif
reg = 0
.rept 32
lfd reg,reg*8+VCPU_FPRS(r4)
reg = reg + 1
.endr
#ifdef CONFIG_VSX
ALT_FTR_SECTION_END_IFSET(CPU_FTR_VSX)
#endif
#ifdef CONFIG_ALTIVEC
BEGIN_FTR_SECTION
li r7,VCPU_VSCR
lvx vr0,r7,r4
mtvscr vr0
reg = 0
.rept 32
li r7,reg*16+VCPU_VRS
lvx reg,r7,r4
reg = reg + 1
.endr
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
#endif
lwz r7,VCPU_VRSAVE(r4)
mtspr SPRN_VRSAVE,r7
blr
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