linux_dsm_epyc7002/arch/powerpc/kvm/book3s_hv_builtin.c

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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
/*
* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
*
* 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.
*/
#include <linux/cpu.h>
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
#include <linux/kvm_host.h>
#include <linux/preempt.h>
#include <linux/export.h>
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
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/sizes.h>
#include <linux/cma.h>
KVM: PPC: Book3S HV: Improve H_CONFER implementation Currently the H_CONFER hcall is implemented in kernel virtual mode, meaning that whenever a guest thread does an H_CONFER, all the threads in that virtual core have to exit the guest. This is bad for performance because it interrupts the other threads even if they are doing useful work. The H_CONFER hcall is called by a guest VCPU when it is spinning on a spinlock and it detects that the spinlock is held by a guest VCPU that is currently not running on a physical CPU. The idea is to give this VCPU's time slice to the holder VCPU so that it can make progress towards releasing the lock. To avoid having the other threads exit the guest unnecessarily, we add a real-mode implementation of H_CONFER that checks whether the other threads are doing anything. If all the other threads are idle (i.e. in H_CEDE) or trying to confer (i.e. in H_CONFER), it returns H_TOO_HARD which causes a guest exit and allows the H_CONFER to be handled in virtual mode. Otherwise it spins for a short time (up to 10 microseconds) to give other threads the chance to observe that this thread is trying to confer. The spin loop also terminates when any thread exits the guest or when all other threads are idle or trying to confer. If the timeout is reached, the H_CONFER returns H_SUCCESS. In this case the guest VCPU will recheck the spinlock word and most likely call H_CONFER again. This also improves the implementation of the H_CONFER virtual mode handler. If the VCPU is part of a virtual core (vcore) which is runnable, there will be a 'runner' VCPU which has taken responsibility for running the vcore. In this case we yield to the runner VCPU rather than the target VCPU. We also introduce a check on the target VCPU's yield count: if it differs from the yield count passed to H_CONFER, the target VCPU has run since H_CONFER was called and may have already released the lock. This check is required by PAPR. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-03 09:30:40 +07:00
#include <linux/bitops.h>
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
#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/archrandom.h>
#include <asm/xics.h>
#include <asm/xive.h>
#include <asm/dbell.h>
#include <asm/cputhreads.h>
#include <asm/io.h>
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
#include <asm/opal.h>
#include <asm/smp.h>
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
#define KVM_CMA_CHUNK_ORDER 18
#include "book3s_xics.h"
#include "book3s_xive.h"
/*
* The XIVE module will populate these when it loads
*/
unsigned long (*__xive_vm_h_xirr)(struct kvm_vcpu *vcpu);
unsigned long (*__xive_vm_h_ipoll)(struct kvm_vcpu *vcpu, unsigned long server);
int (*__xive_vm_h_ipi)(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr);
int (*__xive_vm_h_cppr)(struct kvm_vcpu *vcpu, unsigned long cppr);
int (*__xive_vm_h_eoi)(struct kvm_vcpu *vcpu, unsigned long xirr);
EXPORT_SYMBOL_GPL(__xive_vm_h_xirr);
EXPORT_SYMBOL_GPL(__xive_vm_h_ipoll);
EXPORT_SYMBOL_GPL(__xive_vm_h_ipi);
EXPORT_SYMBOL_GPL(__xive_vm_h_cppr);
EXPORT_SYMBOL_GPL(__xive_vm_h_eoi);
/*
* Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
* should be power of 2.
*/
#define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */
/*
* By default we reserve 5% of memory for hash pagetable allocation.
*/
static unsigned long kvm_cma_resv_ratio = 5;
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
static struct cma *kvm_cma;
static int __init early_parse_kvm_cma_resv(char *p)
{
pr_debug("%s(%s)\n", __func__, p);
if (!p)
return -EINVAL;
return kstrtoul(p, 0, &kvm_cma_resv_ratio);
}
early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
struct page *kvm_alloc_hpt_cma(unsigned long nr_pages)
{
VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES),
GFP_KERNEL);
}
EXPORT_SYMBOL_GPL(kvm_alloc_hpt_cma);
void kvm_free_hpt_cma(struct page *page, unsigned long nr_pages)
{
cma_release(kvm_cma, page, nr_pages);
}
EXPORT_SYMBOL_GPL(kvm_free_hpt_cma);
/**
* kvm_cma_reserve() - reserve area for kvm hash pagetable
*
* This function reserves memory from early allocator. It should be
* called by arch specific code once the memblock allocator
* has been activated and all other subsystems have already allocated/reserved
* memory.
*/
void __init kvm_cma_reserve(void)
{
unsigned long align_size;
struct memblock_region *reg;
phys_addr_t selected_size = 0;
/*
* We need CMA reservation only when we are in HV mode
*/
if (!cpu_has_feature(CPU_FTR_HVMODE))
return;
/*
* We cannot use memblock_phys_mem_size() here, because
* memblock_analyze() has not been called yet.
*/
for_each_memblock(memory, reg)
selected_size += memblock_region_memory_end_pfn(reg) -
memblock_region_memory_base_pfn(reg);
selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
if (selected_size) {
pr_debug("%s: reserving %ld MiB for global area\n", __func__,
(unsigned long)selected_size / SZ_1M);
align_size = HPT_ALIGN_PAGES << PAGE_SHIFT;
cma_declare_contiguous(0, selected_size, 0, align_size,
KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, false, "kvm_cma",
&kvm_cma);
}
}
KVM: PPC: Book3S HV: Improve H_CONFER implementation Currently the H_CONFER hcall is implemented in kernel virtual mode, meaning that whenever a guest thread does an H_CONFER, all the threads in that virtual core have to exit the guest. This is bad for performance because it interrupts the other threads even if they are doing useful work. The H_CONFER hcall is called by a guest VCPU when it is spinning on a spinlock and it detects that the spinlock is held by a guest VCPU that is currently not running on a physical CPU. The idea is to give this VCPU's time slice to the holder VCPU so that it can make progress towards releasing the lock. To avoid having the other threads exit the guest unnecessarily, we add a real-mode implementation of H_CONFER that checks whether the other threads are doing anything. If all the other threads are idle (i.e. in H_CEDE) or trying to confer (i.e. in H_CONFER), it returns H_TOO_HARD which causes a guest exit and allows the H_CONFER to be handled in virtual mode. Otherwise it spins for a short time (up to 10 microseconds) to give other threads the chance to observe that this thread is trying to confer. The spin loop also terminates when any thread exits the guest or when all other threads are idle or trying to confer. If the timeout is reached, the H_CONFER returns H_SUCCESS. In this case the guest VCPU will recheck the spinlock word and most likely call H_CONFER again. This also improves the implementation of the H_CONFER virtual mode handler. If the VCPU is part of a virtual core (vcore) which is runnable, there will be a 'runner' VCPU which has taken responsibility for running the vcore. In this case we yield to the runner VCPU rather than the target VCPU. We also introduce a check on the target VCPU's yield count: if it differs from the yield count passed to H_CONFER, the target VCPU has run since H_CONFER was called and may have already released the lock. This check is required by PAPR. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-03 09:30:40 +07:00
/*
* Real-mode H_CONFER implementation.
* We check if we are the only vcpu out of this virtual core
* still running in the guest and not ceded. If so, we pop up
* to the virtual-mode implementation; if not, just return to
* the guest.
*/
long int kvmppc_rm_h_confer(struct kvm_vcpu *vcpu, int target,
unsigned int yield_count)
{
KVM: PPC: Book3S HV: Make use of unused threads when running guests When running a virtual core of a guest that is configured with fewer threads per core than the physical cores have, the extra physical threads are currently unused. This makes it possible to use them to run one or more other virtual cores from the same guest when certain conditions are met. This applies on POWER7, and on POWER8 to guests with one thread per virtual core. (It doesn't apply to POWER8 guests with multiple threads per vcore because they require a 1-1 virtual to physical thread mapping in order to be able to use msgsndp and the TIR.) The idea is that we maintain a list of preempted vcores for each physical cpu (i.e. each core, since the host runs single-threaded). Then, when a vcore is about to run, it checks to see if there are any vcores on the list for its physical cpu that could be piggybacked onto this vcore's execution. If so, those additional vcores are put into state VCORE_PIGGYBACK and their runnable VCPU threads are started as well as the original vcore, which is called the master vcore. After the vcores have exited the guest, the extra ones are put back onto the preempted list if any of their VCPUs are still runnable and not idle. This means that vcpu->arch.ptid is no longer necessarily the same as the physical thread that the vcpu runs on. In order to make it easier for code that wants to send an IPI to know which CPU to target, we now store that in a new field in struct vcpu_arch, called thread_cpu. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-06-24 18:18:03 +07:00
struct kvmppc_vcore *vc = local_paca->kvm_hstate.kvm_vcore;
int ptid = local_paca->kvm_hstate.ptid;
KVM: PPC: Book3S HV: Improve H_CONFER implementation Currently the H_CONFER hcall is implemented in kernel virtual mode, meaning that whenever a guest thread does an H_CONFER, all the threads in that virtual core have to exit the guest. This is bad for performance because it interrupts the other threads even if they are doing useful work. The H_CONFER hcall is called by a guest VCPU when it is spinning on a spinlock and it detects that the spinlock is held by a guest VCPU that is currently not running on a physical CPU. The idea is to give this VCPU's time slice to the holder VCPU so that it can make progress towards releasing the lock. To avoid having the other threads exit the guest unnecessarily, we add a real-mode implementation of H_CONFER that checks whether the other threads are doing anything. If all the other threads are idle (i.e. in H_CEDE) or trying to confer (i.e. in H_CONFER), it returns H_TOO_HARD which causes a guest exit and allows the H_CONFER to be handled in virtual mode. Otherwise it spins for a short time (up to 10 microseconds) to give other threads the chance to observe that this thread is trying to confer. The spin loop also terminates when any thread exits the guest or when all other threads are idle or trying to confer. If the timeout is reached, the H_CONFER returns H_SUCCESS. In this case the guest VCPU will recheck the spinlock word and most likely call H_CONFER again. This also improves the implementation of the H_CONFER virtual mode handler. If the VCPU is part of a virtual core (vcore) which is runnable, there will be a 'runner' VCPU which has taken responsibility for running the vcore. In this case we yield to the runner VCPU rather than the target VCPU. We also introduce a check on the target VCPU's yield count: if it differs from the yield count passed to H_CONFER, the target VCPU has run since H_CONFER was called and may have already released the lock. This check is required by PAPR. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-03 09:30:40 +07:00
int threads_running;
int threads_ceded;
int threads_conferring;
u64 stop = get_tb() + 10 * tb_ticks_per_usec;
int rv = H_SUCCESS; /* => don't yield */
KVM: PPC: Book3S HV: Make use of unused threads when running guests When running a virtual core of a guest that is configured with fewer threads per core than the physical cores have, the extra physical threads are currently unused. This makes it possible to use them to run one or more other virtual cores from the same guest when certain conditions are met. This applies on POWER7, and on POWER8 to guests with one thread per virtual core. (It doesn't apply to POWER8 guests with multiple threads per vcore because they require a 1-1 virtual to physical thread mapping in order to be able to use msgsndp and the TIR.) The idea is that we maintain a list of preempted vcores for each physical cpu (i.e. each core, since the host runs single-threaded). Then, when a vcore is about to run, it checks to see if there are any vcores on the list for its physical cpu that could be piggybacked onto this vcore's execution. If so, those additional vcores are put into state VCORE_PIGGYBACK and their runnable VCPU threads are started as well as the original vcore, which is called the master vcore. After the vcores have exited the guest, the extra ones are put back onto the preempted list if any of their VCPUs are still runnable and not idle. This means that vcpu->arch.ptid is no longer necessarily the same as the physical thread that the vcpu runs on. In order to make it easier for code that wants to send an IPI to know which CPU to target, we now store that in a new field in struct vcpu_arch, called thread_cpu. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-06-24 18:18:03 +07:00
set_bit(ptid, &vc->conferring_threads);
while ((get_tb() < stop) && !VCORE_IS_EXITING(vc)) {
threads_running = VCORE_ENTRY_MAP(vc);
threads_ceded = vc->napping_threads;
threads_conferring = vc->conferring_threads;
if ((threads_ceded | threads_conferring) == threads_running) {
KVM: PPC: Book3S HV: Improve H_CONFER implementation Currently the H_CONFER hcall is implemented in kernel virtual mode, meaning that whenever a guest thread does an H_CONFER, all the threads in that virtual core have to exit the guest. This is bad for performance because it interrupts the other threads even if they are doing useful work. The H_CONFER hcall is called by a guest VCPU when it is spinning on a spinlock and it detects that the spinlock is held by a guest VCPU that is currently not running on a physical CPU. The idea is to give this VCPU's time slice to the holder VCPU so that it can make progress towards releasing the lock. To avoid having the other threads exit the guest unnecessarily, we add a real-mode implementation of H_CONFER that checks whether the other threads are doing anything. If all the other threads are idle (i.e. in H_CEDE) or trying to confer (i.e. in H_CONFER), it returns H_TOO_HARD which causes a guest exit and allows the H_CONFER to be handled in virtual mode. Otherwise it spins for a short time (up to 10 microseconds) to give other threads the chance to observe that this thread is trying to confer. The spin loop also terminates when any thread exits the guest or when all other threads are idle or trying to confer. If the timeout is reached, the H_CONFER returns H_SUCCESS. In this case the guest VCPU will recheck the spinlock word and most likely call H_CONFER again. This also improves the implementation of the H_CONFER virtual mode handler. If the VCPU is part of a virtual core (vcore) which is runnable, there will be a 'runner' VCPU which has taken responsibility for running the vcore. In this case we yield to the runner VCPU rather than the target VCPU. We also introduce a check on the target VCPU's yield count: if it differs from the yield count passed to H_CONFER, the target VCPU has run since H_CONFER was called and may have already released the lock. This check is required by PAPR. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-03 09:30:40 +07:00
rv = H_TOO_HARD; /* => do yield */
break;
}
}
KVM: PPC: Book3S HV: Make use of unused threads when running guests When running a virtual core of a guest that is configured with fewer threads per core than the physical cores have, the extra physical threads are currently unused. This makes it possible to use them to run one or more other virtual cores from the same guest when certain conditions are met. This applies on POWER7, and on POWER8 to guests with one thread per virtual core. (It doesn't apply to POWER8 guests with multiple threads per vcore because they require a 1-1 virtual to physical thread mapping in order to be able to use msgsndp and the TIR.) The idea is that we maintain a list of preempted vcores for each physical cpu (i.e. each core, since the host runs single-threaded). Then, when a vcore is about to run, it checks to see if there are any vcores on the list for its physical cpu that could be piggybacked onto this vcore's execution. If so, those additional vcores are put into state VCORE_PIGGYBACK and their runnable VCPU threads are started as well as the original vcore, which is called the master vcore. After the vcores have exited the guest, the extra ones are put back onto the preempted list if any of their VCPUs are still runnable and not idle. This means that vcpu->arch.ptid is no longer necessarily the same as the physical thread that the vcpu runs on. In order to make it easier for code that wants to send an IPI to know which CPU to target, we now store that in a new field in struct vcpu_arch, called thread_cpu. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: Laurent Vivier <lvivier@redhat.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-06-24 18:18:03 +07:00
clear_bit(ptid, &vc->conferring_threads);
KVM: PPC: Book3S HV: Improve H_CONFER implementation Currently the H_CONFER hcall is implemented in kernel virtual mode, meaning that whenever a guest thread does an H_CONFER, all the threads in that virtual core have to exit the guest. This is bad for performance because it interrupts the other threads even if they are doing useful work. The H_CONFER hcall is called by a guest VCPU when it is spinning on a spinlock and it detects that the spinlock is held by a guest VCPU that is currently not running on a physical CPU. The idea is to give this VCPU's time slice to the holder VCPU so that it can make progress towards releasing the lock. To avoid having the other threads exit the guest unnecessarily, we add a real-mode implementation of H_CONFER that checks whether the other threads are doing anything. If all the other threads are idle (i.e. in H_CEDE) or trying to confer (i.e. in H_CONFER), it returns H_TOO_HARD which causes a guest exit and allows the H_CONFER to be handled in virtual mode. Otherwise it spins for a short time (up to 10 microseconds) to give other threads the chance to observe that this thread is trying to confer. The spin loop also terminates when any thread exits the guest or when all other threads are idle or trying to confer. If the timeout is reached, the H_CONFER returns H_SUCCESS. In this case the guest VCPU will recheck the spinlock word and most likely call H_CONFER again. This also improves the implementation of the H_CONFER virtual mode handler. If the VCPU is part of a virtual core (vcore) which is runnable, there will be a 'runner' VCPU which has taken responsibility for running the vcore. In this case we yield to the runner VCPU rather than the target VCPU. We also introduce a check on the target VCPU's yield count: if it differs from the yield count passed to H_CONFER, the target VCPU has run since H_CONFER was called and may have already released the lock. This check is required by PAPR. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-12-03 09:30:40 +07:00
return rv;
}
/*
* When running HV mode KVM we need to block certain operations while KVM VMs
* exist in the system. We use a counter of VMs to track this.
*
* One of the operations we need to block is onlining of secondaries, so we
* protect hv_vm_count with get/put_online_cpus().
*/
static atomic_t hv_vm_count;
void kvm_hv_vm_activated(void)
{
get_online_cpus();
atomic_inc(&hv_vm_count);
put_online_cpus();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_activated);
void kvm_hv_vm_deactivated(void)
{
get_online_cpus();
atomic_dec(&hv_vm_count);
put_online_cpus();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated);
bool kvm_hv_mode_active(void)
{
return atomic_read(&hv_vm_count) != 0;
}
extern int hcall_real_table[], hcall_real_table_end[];
int kvmppc_hcall_impl_hv_realmode(unsigned long cmd)
{
cmd /= 4;
if (cmd < hcall_real_table_end - hcall_real_table &&
hcall_real_table[cmd])
return 1;
return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode);
int kvmppc_hwrng_present(void)
{
return powernv_hwrng_present();
}
EXPORT_SYMBOL_GPL(kvmppc_hwrng_present);
long kvmppc_h_random(struct kvm_vcpu *vcpu)
{
KVM: PPC: Book3S HV: Add radix checks in real-mode hypercall handlers POWER9 running a radix guest will take some hypervisor interrupts without going to real mode (turning off the MMU). This means that early hypercall handlers may now be called in virtual mode. Most of the handlers work just fine in both modes, but there are some that can crash the host if called in virtual mode, notably the TCE (IOMMU) hypercalls H_PUT_TCE, H_STUFF_TCE and H_PUT_TCE_INDIRECT. These already have both a real-mode and a virtual-mode version, so we arrange for the real-mode version to return H_TOO_HARD for radix guests, which will result in the virtual-mode version being called. The other hypercall which is sensitive to the MMU mode is H_RANDOM. It doesn't have a virtual-mode version, so this adds code to enable it to be called in either mode. An alternative solution was considered which would refuse to call any of the early hypercall handlers when doing a virtual-mode exit from a radix guest. However, the XICS-on-XIVE code depends on the XICS hypercalls being handled early even for virtual-mode exits, because the handlers need to be called before the XIVE vCPU state has been pulled off the hardware. Therefore that solution would have become quite invasive and complicated, and was rejected in favour of the simpler, though less elegant, solution presented here. Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Tested-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2017-05-10 13:39:41 +07:00
int r;
/* Only need to do the expensive mfmsr() on radix */
if (kvm_is_radix(vcpu->kvm) && (mfmsr() & MSR_IR))
r = powernv_get_random_long(&vcpu->arch.gpr[4]);
else
r = powernv_get_random_real_mode(&vcpu->arch.gpr[4]);
if (r)
return H_SUCCESS;
return H_HARDWARE;
}
/*
* Send an interrupt or message to another CPU.
* The caller needs to include any barrier needed to order writes
* to memory vs. the IPI/message.
*/
void kvmhv_rm_send_ipi(int cpu)
{
void __iomem *xics_phys;
unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
/* On POWER9 we can use msgsnd for any destination cpu. */
if (cpu_has_feature(CPU_FTR_ARCH_300)) {
msg |= get_hard_smp_processor_id(cpu);
__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
return;
}
/* On POWER8 for IPIs to threads in the same core, use msgsnd. */
if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
cpu_first_thread_sibling(cpu) ==
cpu_first_thread_sibling(raw_smp_processor_id())) {
msg |= cpu_thread_in_core(cpu);
__asm__ __volatile__ (PPC_MSGSND(%0) : : "r" (msg));
return;
}
/* We should never reach this */
if (WARN_ON_ONCE(xive_enabled()))
return;
/* Else poke the target with an IPI */
xics_phys = paca[cpu].kvm_hstate.xics_phys;
if (xics_phys)
__raw_rm_writeb(IPI_PRIORITY, xics_phys + XICS_MFRR);
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
else
opal_int_set_mfrr(get_hard_smp_processor_id(cpu), IPI_PRIORITY);
}
/*
* The following functions are called from the assembly code
* in book3s_hv_rmhandlers.S.
*/
static void kvmhv_interrupt_vcore(struct kvmppc_vcore *vc, int active)
{
int cpu = vc->pcpu;
/* Order setting of exit map vs. msgsnd/IPI */
smp_mb();
for (; active; active >>= 1, ++cpu)
if (active & 1)
kvmhv_rm_send_ipi(cpu);
}
void kvmhv_commence_exit(int trap)
{
struct kvmppc_vcore *vc = local_paca->kvm_hstate.kvm_vcore;
int ptid = local_paca->kvm_hstate.ptid;
KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8 This builds on the ability to run more than one vcore on a physical core by using the micro-threading (split-core) modes of the POWER8 chip. Previously, only vcores from the same VM could be run together, and (on POWER8) only if they had just one thread per core. With the ability to split the core on guest entry and unsplit it on guest exit, we can run up to 8 vcpu threads from up to 4 different VMs, and we can run multiple vcores with 2 or 4 vcpus per vcore. Dynamic micro-threading is only available if the static configuration of the cores is whole-core mode (unsplit), and only on POWER8. To manage this, we introduce a new kvm_split_mode struct which is shared across all of the subcores in the core, with a pointer in the paca on each thread. In addition we extend the core_info struct to have information on each subcore. When deciding whether to add a vcore to the set already on the core, we now have two possibilities: (a) piggyback the vcore onto an existing subcore, or (b) start a new subcore. Currently, when any vcpu needs to exit the guest and switch to host virtual mode, we interrupt all the threads in all subcores and switch the core back to whole-core mode. It may be possible in future to allow some of the subcores to keep executing in the guest while subcore 0 switches to the host, but that is not implemented in this patch. This adds a module parameter called dynamic_mt_modes which controls which micro-threading (split-core) modes the code will consider, as a bitmap. In other words, if it is 0, no micro-threading mode is considered; if it is 2, only 2-way micro-threading is considered; if it is 4, only 4-way, and if it is 6, both 2-way and 4-way micro-threading mode will be considered. The default is 6. With this, we now have secondary threads which are the primary thread for their subcore and therefore need to do the MMU switch. These threads will need to be started even if they have no vcpu to run, so we use the vcore pointer in the PACA rather than the vcpu pointer to trigger them. It is now possible for thread 0 to find that an exit has been requested before it gets to switch the subcore state to the guest. In that case we haven't added the guest's timebase offset to the timebase, so we need to be careful not to subtract the offset in the guest exit path. In fact we just skip the whole path that switches back to host context, since we haven't switched to the guest context. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-07-02 17:38:16 +07:00
struct kvm_split_mode *sip = local_paca->kvm_hstate.kvm_split_mode;
int me, ee, i;
/* Set our bit in the threads-exiting-guest map in the 0xff00
bits of vcore->entry_exit_map */
me = 0x100 << ptid;
do {
ee = vc->entry_exit_map;
} while (cmpxchg(&vc->entry_exit_map, ee, ee | me) != ee);
/* Are we the first here? */
if ((ee >> 8) != 0)
return;
/*
* Trigger the other threads in this vcore to exit the guest.
* If this is a hypervisor decrementer interrupt then they
* will be already on their way out of the guest.
*/
if (trap != BOOK3S_INTERRUPT_HV_DECREMENTER)
kvmhv_interrupt_vcore(vc, ee & ~(1 << ptid));
KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8 This builds on the ability to run more than one vcore on a physical core by using the micro-threading (split-core) modes of the POWER8 chip. Previously, only vcores from the same VM could be run together, and (on POWER8) only if they had just one thread per core. With the ability to split the core on guest entry and unsplit it on guest exit, we can run up to 8 vcpu threads from up to 4 different VMs, and we can run multiple vcores with 2 or 4 vcpus per vcore. Dynamic micro-threading is only available if the static configuration of the cores is whole-core mode (unsplit), and only on POWER8. To manage this, we introduce a new kvm_split_mode struct which is shared across all of the subcores in the core, with a pointer in the paca on each thread. In addition we extend the core_info struct to have information on each subcore. When deciding whether to add a vcore to the set already on the core, we now have two possibilities: (a) piggyback the vcore onto an existing subcore, or (b) start a new subcore. Currently, when any vcpu needs to exit the guest and switch to host virtual mode, we interrupt all the threads in all subcores and switch the core back to whole-core mode. It may be possible in future to allow some of the subcores to keep executing in the guest while subcore 0 switches to the host, but that is not implemented in this patch. This adds a module parameter called dynamic_mt_modes which controls which micro-threading (split-core) modes the code will consider, as a bitmap. In other words, if it is 0, no micro-threading mode is considered; if it is 2, only 2-way micro-threading is considered; if it is 4, only 4-way, and if it is 6, both 2-way and 4-way micro-threading mode will be considered. The default is 6. With this, we now have secondary threads which are the primary thread for their subcore and therefore need to do the MMU switch. These threads will need to be started even if they have no vcpu to run, so we use the vcore pointer in the PACA rather than the vcpu pointer to trigger them. It is now possible for thread 0 to find that an exit has been requested before it gets to switch the subcore state to the guest. In that case we haven't added the guest's timebase offset to the timebase, so we need to be careful not to subtract the offset in the guest exit path. In fact we just skip the whole path that switches back to host context, since we haven't switched to the guest context. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-07-02 17:38:16 +07:00
/*
* If we are doing dynamic micro-threading, interrupt the other
* subcores to pull them out of their guests too.
*/
if (!sip)
return;
for (i = 0; i < MAX_SUBCORES; ++i) {
vc = sip->vc[i];
KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8 This builds on the ability to run more than one vcore on a physical core by using the micro-threading (split-core) modes of the POWER8 chip. Previously, only vcores from the same VM could be run together, and (on POWER8) only if they had just one thread per core. With the ability to split the core on guest entry and unsplit it on guest exit, we can run up to 8 vcpu threads from up to 4 different VMs, and we can run multiple vcores with 2 or 4 vcpus per vcore. Dynamic micro-threading is only available if the static configuration of the cores is whole-core mode (unsplit), and only on POWER8. To manage this, we introduce a new kvm_split_mode struct which is shared across all of the subcores in the core, with a pointer in the paca on each thread. In addition we extend the core_info struct to have information on each subcore. When deciding whether to add a vcore to the set already on the core, we now have two possibilities: (a) piggyback the vcore onto an existing subcore, or (b) start a new subcore. Currently, when any vcpu needs to exit the guest and switch to host virtual mode, we interrupt all the threads in all subcores and switch the core back to whole-core mode. It may be possible in future to allow some of the subcores to keep executing in the guest while subcore 0 switches to the host, but that is not implemented in this patch. This adds a module parameter called dynamic_mt_modes which controls which micro-threading (split-core) modes the code will consider, as a bitmap. In other words, if it is 0, no micro-threading mode is considered; if it is 2, only 2-way micro-threading is considered; if it is 4, only 4-way, and if it is 6, both 2-way and 4-way micro-threading mode will be considered. The default is 6. With this, we now have secondary threads which are the primary thread for their subcore and therefore need to do the MMU switch. These threads will need to be started even if they have no vcpu to run, so we use the vcore pointer in the PACA rather than the vcpu pointer to trigger them. It is now possible for thread 0 to find that an exit has been requested before it gets to switch the subcore state to the guest. In that case we haven't added the guest's timebase offset to the timebase, so we need to be careful not to subtract the offset in the guest exit path. In fact we just skip the whole path that switches back to host context, since we haven't switched to the guest context. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2015-07-02 17:38:16 +07:00
if (!vc)
break;
do {
ee = vc->entry_exit_map;
/* Already asked to exit? */
if ((ee >> 8) != 0)
break;
} while (cmpxchg(&vc->entry_exit_map, ee,
ee | VCORE_EXIT_REQ) != ee);
if ((ee >> 8) == 0)
kvmhv_interrupt_vcore(vc, ee);
}
}
KVM: PPC: Book3S HV: Host-side RM data structures This patch defines the data structures to support the setting up of host side operations while running in real mode in the guest, and also the functions to allocate and free it. The operations are for now limited to virtual XICS operations. Currently, we have only defined one operation in the data structure: - Wake up a VCPU sleeping in the host when it receives a virtual interrupt The operations are assigned at the core level because PowerKVM requires that the host run in SMT off mode. For each core, we will need to manage its state atomically - where the state is defined by: 1. Is the core running in the host? 2. Is there a Real Mode (RM) operation pending on the host? Currently, core state is only managed at the whole-core level even when the system is in split-core mode. This just limits the number of free or "available" cores in the host to perform any host-side operations. The kvmppc_host_rm_core.rm_data allows any data to be passed by KVM in real mode to the host core along with the operation to be performed. The kvmppc_host_rm_ops structure is allocated the very first time a guest VM is started. Initial core state is also set - all online cores are in the host. This structure is never deleted, not even when there are no active guests. However, it needs to be freed when the module is unloaded because the kvmppc_host_rm_ops_hv can contain function pointers to kvm-hv.ko functions for the different supported host operations. Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2015-12-18 03:59:06 +07:00
struct kvmppc_host_rm_ops *kvmppc_host_rm_ops_hv;
EXPORT_SYMBOL_GPL(kvmppc_host_rm_ops_hv);
KVM: PPC: Book3S HV: Handle passthrough interrupts in guest Currently, KVM switches back to the host to handle any external interrupt (when the interrupt is received while running in the guest). This patch updates real-mode KVM to check if an interrupt is generated by a passthrough adapter that is owned by this guest. If so, the real mode KVM will directly inject the corresponding virtual interrupt to the guest VCPU's ICS and also EOI the interrupt in hardware. In short, the interrupt is handled entirely in real mode in the guest context without switching back to the host. In some rare cases, the interrupt cannot be completely handled in real mode, for instance, a VCPU that is sleeping needs to be woken up. In this case, KVM simply switches back to the host with trap reason set to 0x500. This works, but it is clearly not very efficient. A following patch will distinguish this case and handle it correctly in the host. Note that we can use the existing check_too_hard() routine even though we are not in a hypercall to determine if there is unfinished business that needs to be completed in host virtual mode. The patch assumes that the mapping between hardware interrupt IRQ and virtual IRQ to be injected to the guest already exists for the PCI passthrough interrupts that need to be handled in real mode. If the mapping does not exist, KVM falls back to the default existing behavior. The KVM real mode code reads mappings from the mapped array in the passthrough IRQ map without taking any lock. We carefully order the loads and stores of the fields in the kvmppc_irq_map data structure using memory barriers to avoid an inconsistent mapping being seen by the reader. Thus, although it is possible to miss a map entry, it is not possible to read a stale value. [paulus@ozlabs.org - get irq_chip from irq_map rather than pimap, pulled out powernv eoi change into a separate patch, made kvmppc_read_intr get the vcpu from the paca rather than being passed in, rewrote the logic at the end of kvmppc_read_intr to avoid deep indentation, simplified logic in book3s_hv_rmhandlers.S since we were always restoring SRR0/1 anyway, get rid of the cached array (just use the mapped array), removed the kick_all_cpus_sync() call, clear saved_xirr PACA field when we handle the interrupt in real mode, fix compilation with CONFIG_KVM_XICS=n.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 12:35:51 +07:00
#ifdef CONFIG_KVM_XICS
static struct kvmppc_irq_map *get_irqmap(struct kvmppc_passthru_irqmap *pimap,
u32 xisr)
{
int i;
/*
* We access the mapped array here without a lock. That
* is safe because we never reduce the number of entries
* in the array and we never change the v_hwirq field of
* an entry once it is set.
*
* We have also carefully ordered the stores in the writer
* and the loads here in the reader, so that if we find a matching
* hwirq here, the associated GSI and irq_desc fields are valid.
*/
for (i = 0; i < pimap->n_mapped; i++) {
if (xisr == pimap->mapped[i].r_hwirq) {
/*
* Order subsequent reads in the caller to serialize
* with the writer.
*/
smp_rmb();
return &pimap->mapped[i];
}
}
return NULL;
}
/*
* If we have an interrupt that's not an IPI, check if we have a
* passthrough adapter and if so, check if this external interrupt
* is for the adapter.
* We will attempt to deliver the IRQ directly to the target VCPU's
* ICP, the virtual ICP (based on affinity - the xive value in ICS).
*
* If the delivery fails or if this is not for a passthrough adapter,
* return to the host to handle this interrupt. We earlier
* saved a copy of the XIRR in the PACA, it will be picked up by
* the host ICP driver.
*/
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
static int kvmppc_check_passthru(u32 xisr, __be32 xirr, bool *again)
KVM: PPC: Book3S HV: Handle passthrough interrupts in guest Currently, KVM switches back to the host to handle any external interrupt (when the interrupt is received while running in the guest). This patch updates real-mode KVM to check if an interrupt is generated by a passthrough adapter that is owned by this guest. If so, the real mode KVM will directly inject the corresponding virtual interrupt to the guest VCPU's ICS and also EOI the interrupt in hardware. In short, the interrupt is handled entirely in real mode in the guest context without switching back to the host. In some rare cases, the interrupt cannot be completely handled in real mode, for instance, a VCPU that is sleeping needs to be woken up. In this case, KVM simply switches back to the host with trap reason set to 0x500. This works, but it is clearly not very efficient. A following patch will distinguish this case and handle it correctly in the host. Note that we can use the existing check_too_hard() routine even though we are not in a hypercall to determine if there is unfinished business that needs to be completed in host virtual mode. The patch assumes that the mapping between hardware interrupt IRQ and virtual IRQ to be injected to the guest already exists for the PCI passthrough interrupts that need to be handled in real mode. If the mapping does not exist, KVM falls back to the default existing behavior. The KVM real mode code reads mappings from the mapped array in the passthrough IRQ map without taking any lock. We carefully order the loads and stores of the fields in the kvmppc_irq_map data structure using memory barriers to avoid an inconsistent mapping being seen by the reader. Thus, although it is possible to miss a map entry, it is not possible to read a stale value. [paulus@ozlabs.org - get irq_chip from irq_map rather than pimap, pulled out powernv eoi change into a separate patch, made kvmppc_read_intr get the vcpu from the paca rather than being passed in, rewrote the logic at the end of kvmppc_read_intr to avoid deep indentation, simplified logic in book3s_hv_rmhandlers.S since we were always restoring SRR0/1 anyway, get rid of the cached array (just use the mapped array), removed the kick_all_cpus_sync() call, clear saved_xirr PACA field when we handle the interrupt in real mode, fix compilation with CONFIG_KVM_XICS=n.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 12:35:51 +07:00
{
struct kvmppc_passthru_irqmap *pimap;
struct kvmppc_irq_map *irq_map;
struct kvm_vcpu *vcpu;
vcpu = local_paca->kvm_hstate.kvm_vcpu;
if (!vcpu)
return 1;
pimap = kvmppc_get_passthru_irqmap(vcpu->kvm);
if (!pimap)
return 1;
irq_map = get_irqmap(pimap, xisr);
if (!irq_map)
return 1;
/* We're handling this interrupt, generic code doesn't need to */
local_paca->kvm_hstate.saved_xirr = 0;
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
return kvmppc_deliver_irq_passthru(vcpu, xirr, irq_map, pimap, again);
KVM: PPC: Book3S HV: Handle passthrough interrupts in guest Currently, KVM switches back to the host to handle any external interrupt (when the interrupt is received while running in the guest). This patch updates real-mode KVM to check if an interrupt is generated by a passthrough adapter that is owned by this guest. If so, the real mode KVM will directly inject the corresponding virtual interrupt to the guest VCPU's ICS and also EOI the interrupt in hardware. In short, the interrupt is handled entirely in real mode in the guest context without switching back to the host. In some rare cases, the interrupt cannot be completely handled in real mode, for instance, a VCPU that is sleeping needs to be woken up. In this case, KVM simply switches back to the host with trap reason set to 0x500. This works, but it is clearly not very efficient. A following patch will distinguish this case and handle it correctly in the host. Note that we can use the existing check_too_hard() routine even though we are not in a hypercall to determine if there is unfinished business that needs to be completed in host virtual mode. The patch assumes that the mapping between hardware interrupt IRQ and virtual IRQ to be injected to the guest already exists for the PCI passthrough interrupts that need to be handled in real mode. If the mapping does not exist, KVM falls back to the default existing behavior. The KVM real mode code reads mappings from the mapped array in the passthrough IRQ map without taking any lock. We carefully order the loads and stores of the fields in the kvmppc_irq_map data structure using memory barriers to avoid an inconsistent mapping being seen by the reader. Thus, although it is possible to miss a map entry, it is not possible to read a stale value. [paulus@ozlabs.org - get irq_chip from irq_map rather than pimap, pulled out powernv eoi change into a separate patch, made kvmppc_read_intr get the vcpu from the paca rather than being passed in, rewrote the logic at the end of kvmppc_read_intr to avoid deep indentation, simplified logic in book3s_hv_rmhandlers.S since we were always restoring SRR0/1 anyway, get rid of the cached array (just use the mapped array), removed the kick_all_cpus_sync() call, clear saved_xirr PACA field when we handle the interrupt in real mode, fix compilation with CONFIG_KVM_XICS=n.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 12:35:51 +07:00
}
#else
static inline int kvmppc_check_passthru(u32 xisr, __be32 xirr, bool *again)
KVM: PPC: Book3S HV: Handle passthrough interrupts in guest Currently, KVM switches back to the host to handle any external interrupt (when the interrupt is received while running in the guest). This patch updates real-mode KVM to check if an interrupt is generated by a passthrough adapter that is owned by this guest. If so, the real mode KVM will directly inject the corresponding virtual interrupt to the guest VCPU's ICS and also EOI the interrupt in hardware. In short, the interrupt is handled entirely in real mode in the guest context without switching back to the host. In some rare cases, the interrupt cannot be completely handled in real mode, for instance, a VCPU that is sleeping needs to be woken up. In this case, KVM simply switches back to the host with trap reason set to 0x500. This works, but it is clearly not very efficient. A following patch will distinguish this case and handle it correctly in the host. Note that we can use the existing check_too_hard() routine even though we are not in a hypercall to determine if there is unfinished business that needs to be completed in host virtual mode. The patch assumes that the mapping between hardware interrupt IRQ and virtual IRQ to be injected to the guest already exists for the PCI passthrough interrupts that need to be handled in real mode. If the mapping does not exist, KVM falls back to the default existing behavior. The KVM real mode code reads mappings from the mapped array in the passthrough IRQ map without taking any lock. We carefully order the loads and stores of the fields in the kvmppc_irq_map data structure using memory barriers to avoid an inconsistent mapping being seen by the reader. Thus, although it is possible to miss a map entry, it is not possible to read a stale value. [paulus@ozlabs.org - get irq_chip from irq_map rather than pimap, pulled out powernv eoi change into a separate patch, made kvmppc_read_intr get the vcpu from the paca rather than being passed in, rewrote the logic at the end of kvmppc_read_intr to avoid deep indentation, simplified logic in book3s_hv_rmhandlers.S since we were always restoring SRR0/1 anyway, get rid of the cached array (just use the mapped array), removed the kick_all_cpus_sync() call, clear saved_xirr PACA field when we handle the interrupt in real mode, fix compilation with CONFIG_KVM_XICS=n.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 12:35:51 +07:00
{
return 1;
}
#endif
/*
* Determine what sort of external interrupt is pending (if any).
* Returns:
* 0 if no interrupt is pending
* 1 if an interrupt is pending that needs to be handled by the host
KVM: PPC: Book3S HV: Complete passthrough interrupt in host In existing real mode ICP code, when updating the virtual ICP state, if there is a required action that cannot be completely handled in real mode, as for instance, a VCPU needs to be woken up, flags are set in the ICP to indicate the required action. This is checked when returning from hypercalls to decide whether the call needs switch back to the host where the action can be performed in virtual mode. Note that if h_ipi_redirect is enabled, real mode code will first try to message a free host CPU to complete this job instead of returning the host to do it ourselves. Currently, the real mode PCI passthrough interrupt handling code checks if any of these flags are set and simply returns to the host. This is not good enough as the trap value (0x500) is treated as an external interrupt by the host code. It is only when the trap value is a hypercall that the host code searches for and acts on unfinished work by calling kvmppc_xics_rm_complete. This patch introduces a special trap BOOK3S_INTERRUPT_HV_RM_HARD which is returned by KVM if there is unfinished business to be completed in host virtual mode after handling a PCI passthrough interrupt. The host checks for this special interrupt condition and calls into the kvmppc_xics_rm_complete, which is made an exported function for this reason. [paulus@ozlabs.org - moved logic to set r12 to BOOK3S_INTERRUPT_HV_RM_HARD in book3s_hv_rmhandlers.S into the end of kvmppc_check_wake_reason.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 12:35:52 +07:00
* 2 Passthrough that needs completion in the host
* -1 if there was a guest wakeup IPI (which has now been cleared)
KVM: PPC: Book3S HV: Handle passthrough interrupts in guest Currently, KVM switches back to the host to handle any external interrupt (when the interrupt is received while running in the guest). This patch updates real-mode KVM to check if an interrupt is generated by a passthrough adapter that is owned by this guest. If so, the real mode KVM will directly inject the corresponding virtual interrupt to the guest VCPU's ICS and also EOI the interrupt in hardware. In short, the interrupt is handled entirely in real mode in the guest context without switching back to the host. In some rare cases, the interrupt cannot be completely handled in real mode, for instance, a VCPU that is sleeping needs to be woken up. In this case, KVM simply switches back to the host with trap reason set to 0x500. This works, but it is clearly not very efficient. A following patch will distinguish this case and handle it correctly in the host. Note that we can use the existing check_too_hard() routine even though we are not in a hypercall to determine if there is unfinished business that needs to be completed in host virtual mode. The patch assumes that the mapping between hardware interrupt IRQ and virtual IRQ to be injected to the guest already exists for the PCI passthrough interrupts that need to be handled in real mode. If the mapping does not exist, KVM falls back to the default existing behavior. The KVM real mode code reads mappings from the mapped array in the passthrough IRQ map without taking any lock. We carefully order the loads and stores of the fields in the kvmppc_irq_map data structure using memory barriers to avoid an inconsistent mapping being seen by the reader. Thus, although it is possible to miss a map entry, it is not possible to read a stale value. [paulus@ozlabs.org - get irq_chip from irq_map rather than pimap, pulled out powernv eoi change into a separate patch, made kvmppc_read_intr get the vcpu from the paca rather than being passed in, rewrote the logic at the end of kvmppc_read_intr to avoid deep indentation, simplified logic in book3s_hv_rmhandlers.S since we were always restoring SRR0/1 anyway, get rid of the cached array (just use the mapped array), removed the kick_all_cpus_sync() call, clear saved_xirr PACA field when we handle the interrupt in real mode, fix compilation with CONFIG_KVM_XICS=n.] Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-08-19 12:35:51 +07:00
* -2 if there is PCI passthrough external interrupt that was handled
*/
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
static long kvmppc_read_one_intr(bool *again);
long kvmppc_read_intr(void)
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
{
long ret = 0;
long rc;
bool again;
if (xive_enabled())
return 1;
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
do {
again = false;
rc = kvmppc_read_one_intr(&again);
if (rc && (ret == 0 || rc > ret))
ret = rc;
} while (again);
return ret;
}
static long kvmppc_read_one_intr(bool *again)
{
void __iomem *xics_phys;
u32 h_xirr;
__be32 xirr;
u32 xisr;
u8 host_ipi;
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
int64_t rc;
if (xive_enabled())
return 1;
/* see if a host IPI is pending */
host_ipi = local_paca->kvm_hstate.host_ipi;
if (host_ipi)
return 1;
/* Now read the interrupt from the ICP */
xics_phys = local_paca->kvm_hstate.xics_phys;
rc = 0;
if (!xics_phys)
rc = opal_int_get_xirr(&xirr, false);
else
xirr = __raw_rm_readl(xics_phys + XICS_XIRR);
if (rc < 0)
return 1;
/*
* Save XIRR for later. Since we get control in reverse endian
* on LE systems, save it byte reversed and fetch it back in
* host endian. Note that xirr is the value read from the
* XIRR register, while h_xirr is the host endian version.
*/
h_xirr = be32_to_cpu(xirr);
local_paca->kvm_hstate.saved_xirr = h_xirr;
xisr = h_xirr & 0xffffff;
/*
* Ensure that the store/load complete to guarantee all side
* effects of loading from XIRR has completed
*/
smp_mb();
/* if nothing pending in the ICP */
if (!xisr)
return 0;
/* We found something in the ICP...
*
* If it is an IPI, clear the MFRR and EOI it.
*/
if (xisr == XICS_IPI) {
rc = 0;
if (xics_phys) {
__raw_rm_writeb(0xff, xics_phys + XICS_MFRR);
__raw_rm_writel(xirr, xics_phys + XICS_XIRR);
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
} else {
opal_int_set_mfrr(hard_smp_processor_id(), 0xff);
rc = opal_int_eoi(h_xirr);
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
}
/* If rc > 0, there is another interrupt pending */
*again = rc > 0;
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
/*
* Need to ensure side effects of above stores
* complete before proceeding.
*/
smp_mb();
/*
* We need to re-check host IPI now in case it got set in the
* meantime. If it's clear, we bounce the interrupt to the
* guest
*/
host_ipi = local_paca->kvm_hstate.host_ipi;
if (unlikely(host_ipi != 0)) {
/* We raced with the host,
* we need to resend that IPI, bummer
*/
if (xics_phys)
__raw_rm_writeb(IPI_PRIORITY,
xics_phys + XICS_MFRR);
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
else
opal_int_set_mfrr(hard_smp_processor_id(),
IPI_PRIORITY);
/* Let side effects complete */
smp_mb();
return 1;
}
/* OK, it's an IPI for us */
local_paca->kvm_hstate.saved_xirr = 0;
return -1;
}
KVM: PPC: Book3S HV: Use OPAL XICS emulation on POWER9 POWER9 includes a new interrupt controller, called XIVE, which is quite different from the XICS interrupt controller on POWER7 and POWER8 machines. KVM-HV accesses the XICS directly in several places in order to send and clear IPIs and handle interrupts from PCI devices being passed through to the guest. In order to make the transition to XIVE easier, OPAL firmware will include an emulation of XICS on top of XIVE. Access to the emulated XICS is via OPAL calls. The one complication is that the EOI (end-of-interrupt) function can now return a value indicating that another interrupt is pending; in this case, the XIVE will not signal an interrupt in hardware to the CPU, and software is supposed to acknowledge the new interrupt without waiting for another interrupt to be delivered in hardware. This adapts KVM-HV to use the OPAL calls on machines where there is no XICS hardware. When there is no XICS, we look for a device-tree node with "ibm,opal-intc" in its compatible property, which is how OPAL indicates that it provides XICS emulation. In order to handle the EOI return value, kvmppc_read_intr() has become kvmppc_read_one_intr(), with a boolean variable passed by reference which can be set by the EOI functions to indicate that another interrupt is pending. The new kvmppc_read_intr() keeps calling kvmppc_read_one_intr() until there are no more interrupts to process. The return value from kvmppc_read_intr() is the largest non-zero value of the returns from kvmppc_read_one_intr(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2016-11-18 05:02:08 +07:00
return kvmppc_check_passthru(xisr, xirr, again);
}
#ifdef CONFIG_KVM_XICS
static inline bool is_rm(void)
{
return !(mfmsr() & MSR_DR);
}
unsigned long kvmppc_rm_h_xirr(struct kvm_vcpu *vcpu)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_xirr(vcpu);
if (unlikely(!__xive_vm_h_xirr))
return H_NOT_AVAILABLE;
return __xive_vm_h_xirr(vcpu);
} else
return xics_rm_h_xirr(vcpu);
}
unsigned long kvmppc_rm_h_xirr_x(struct kvm_vcpu *vcpu)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
vcpu->arch.gpr[5] = get_tb();
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_xirr(vcpu);
if (unlikely(!__xive_vm_h_xirr))
return H_NOT_AVAILABLE;
return __xive_vm_h_xirr(vcpu);
} else
return xics_rm_h_xirr(vcpu);
}
unsigned long kvmppc_rm_h_ipoll(struct kvm_vcpu *vcpu, unsigned long server)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_ipoll(vcpu, server);
if (unlikely(!__xive_vm_h_ipoll))
return H_NOT_AVAILABLE;
return __xive_vm_h_ipoll(vcpu, server);
} else
return H_TOO_HARD;
}
int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
unsigned long mfrr)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_ipi(vcpu, server, mfrr);
if (unlikely(!__xive_vm_h_ipi))
return H_NOT_AVAILABLE;
return __xive_vm_h_ipi(vcpu, server, mfrr);
} else
return xics_rm_h_ipi(vcpu, server, mfrr);
}
int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_cppr(vcpu, cppr);
if (unlikely(!__xive_vm_h_cppr))
return H_NOT_AVAILABLE;
return __xive_vm_h_cppr(vcpu, cppr);
} else
return xics_rm_h_cppr(vcpu, cppr);
}
int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
{
if (!kvmppc_xics_enabled(vcpu))
return H_TOO_HARD;
if (xive_enabled()) {
if (is_rm())
return xive_rm_h_eoi(vcpu, xirr);
if (unlikely(!__xive_vm_h_eoi))
return H_NOT_AVAILABLE;
return __xive_vm_h_eoi(vcpu, xirr);
} else
return xics_rm_h_eoi(vcpu, xirr);
}
#endif /* CONFIG_KVM_XICS */
void kvmppc_bad_interrupt(struct pt_regs *regs)
{
die("Bad interrupt in KVM entry/exit code", regs, SIGABRT);
panic("Bad KVM trap");
}