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linux_dsm_epyc7002/arch/powerpc/kvm/book3s_rmhandlers.S

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Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright SUSE Linux Products GmbH 2009
*
* Authors: Alexander Graf <agraf@suse.de>
*/
#include <asm/ppc_asm.h>
#include <asm/kvm_asm.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>
#include <asm/exception-64s.h>
/*****************************************************************************
* *
* Real Mode handlers that need to be in low physical memory *
* *
****************************************************************************/
.macro INTERRUPT_TRAMPOLINE intno
.global kvmppc_trampoline_\intno
kvmppc_trampoline_\intno:
mtspr SPRN_SPRG_SCRATCH0, r13 /* Save r13 */
/*
* First thing to do is to find out if we're coming
* from a KVM guest or a Linux process.
*
* To distinguish, we check a magic byte in the PACA
*/
mfspr r13, SPRN_SPRG_PACA /* r13 = PACA */
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:03 +07:00
std r12, PACA_KVM_SCRATCH0(r13)
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
mfcr r12
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:03 +07:00
stw r12, PACA_KVM_SCRATCH1(r13)
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
lbz r12, PACA_KVM_IN_GUEST(r13)
KVM: PPC: Implement 'skip instruction' mode To fetch the last instruction we were interrupted on, we enable DR in early exit code, where we are still in a very transitional phase between guest and host state. Most of the time this seemed to work, but another CPU can easily flush our TLB and HTAB which makes us go in the Linux page fault handler which totally breaks because we still use the guest's SLB entries. To work around that, let's introduce a second KVM guest mode that defines that whenever we get a trap, we don't call the Linux handler or go into the KVM exit code, but just jump over the faulting instruction. That way a potentially bad lwz doesn't trigger any faults and we can later on interpret the invalid instruction we fetched as "fetch didn't work". Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:04 +07:00
cmpwi r12, KVM_GUEST_MODE_NONE
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
bne ..kvmppc_handler_hasmagic_\intno
/* No KVM guest? Then jump back to the Linux handler! */
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:03 +07:00
lwz r12, PACA_KVM_SCRATCH1(r13)
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
mtcr r12
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:03 +07:00
ld r12, PACA_KVM_SCRATCH0(r13)
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
mfspr r13, SPRN_SPRG_SCRATCH0 /* r13 = original r13 */
b kvmppc_resume_\intno /* Get back original handler */
/* Now we know we're handling a KVM guest */
..kvmppc_handler_hasmagic_\intno:
KVM: PPC: Implement 'skip instruction' mode To fetch the last instruction we were interrupted on, we enable DR in early exit code, where we are still in a very transitional phase between guest and host state. Most of the time this seemed to work, but another CPU can easily flush our TLB and HTAB which makes us go in the Linux page fault handler which totally breaks because we still use the guest's SLB entries. To work around that, let's introduce a second KVM guest mode that defines that whenever we get a trap, we don't call the Linux handler or go into the KVM exit code, but just jump over the faulting instruction. That way a potentially bad lwz doesn't trigger any faults and we can later on interpret the invalid instruction we fetched as "fetch didn't work". Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:04 +07:00
/* Should we just skip the faulting instruction? */
cmpwi r12, KVM_GUEST_MODE_SKIP
beq kvmppc_handler_skip_ins
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
/* Let's store which interrupt we're handling */
li r12, \intno
/* Jump into the SLB exit code that goes to the highmem handler */
b kvmppc_handler_trampoline_exit
.endm
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSTEM_RESET
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_MACHINE_CHECK
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_STORAGE
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DATA_SEGMENT
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_STORAGE
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_INST_SEGMENT
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_EXTERNAL
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALIGNMENT
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PROGRAM
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_FP_UNAVAIL
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_DECREMENTER
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_SYSCALL
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_TRACE
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_PERFMON
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_ALTIVEC
INTERRUPT_TRAMPOLINE BOOK3S_INTERRUPT_VSX
KVM: PPC: Implement 'skip instruction' mode To fetch the last instruction we were interrupted on, we enable DR in early exit code, where we are still in a very transitional phase between guest and host state. Most of the time this seemed to work, but another CPU can easily flush our TLB and HTAB which makes us go in the Linux page fault handler which totally breaks because we still use the guest's SLB entries. To work around that, let's introduce a second KVM guest mode that defines that whenever we get a trap, we don't call the Linux handler or go into the KVM exit code, but just jump over the faulting instruction. That way a potentially bad lwz doesn't trigger any faults and we can later on interpret the invalid instruction we fetched as "fetch didn't work". Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:04 +07:00
/*
* Bring us back to the faulting code, but skip the
* faulting instruction.
*
* This is a generic exit path from the interrupt
* trampolines above.
*
* Input Registers:
*
* R12 = free
* R13 = PACA
* PACA.KVM.SCRATCH0 = guest R12
* PACA.KVM.SCRATCH1 = guest CR
* SPRG_SCRATCH0 = guest R13
*
*/
kvmppc_handler_skip_ins:
/* Patch the IP to the next instruction */
mfsrr0 r12
addi r12, r12, 4
mtsrr0 r12
/* Clean up all state */
lwz r12, PACA_KVM_SCRATCH1(r13)
mtcr r12
ld r12, PACA_KVM_SCRATCH0(r13)
mfspr r13, SPRN_SPRG_SCRATCH0
/* And get back into the code */
RFI
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
/*
* This trampoline brings us back to a real mode handler
*
* Input Registers:
*
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:03 +07:00
* R5 = SRR0
* R6 = SRR1
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
* LR = real-mode IP
*
*/
.global kvmppc_handler_lowmem_trampoline
kvmppc_handler_lowmem_trampoline:
KVM: PPC: Use PACA backed shadow vcpu We're being horribly racy right now. All the entry and exit code hijacks random fields from the PACA that could easily be used by different code in case we get interrupted, for example by a #MC or even page fault. After discussing this with Ben, we figured it's best to reserve some more space in the PACA and just shove off some vcpu state to there. That way we can drastically improve the readability of the code, make it less racy and less complex. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:03 +07:00
mtsrr0 r5
mtsrr1 r6
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
blr
kvmppc_handler_lowmem_trampoline_end:
KVM: PPC: Call SLB patching code in interrupt safe manner Currently we're racy when doing the transition from IR=1 to IR=0, from the module memory entry code to the real mode SLB switching code. To work around that I took a look at the RTAS entry code which is faced with a similar problem and did the same thing: A small helper in linear mapped memory that does mtmsr with IR=0 and then RFIs info the actual handler. Thanks to that trick we can safely take page faults in the entry code and only need to be really wary of what to do as of the SLB switching part. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-08 08:58:06 +07:00
/*
* Call a function in real mode
*
* Input Registers:
*
* R3 = function
* R4 = MSR
* R5 = CTR
*
*/
_GLOBAL(kvmppc_rmcall)
mtmsr r4 /* Disable relocation, so mtsrr
doesn't get interrupted */
mtctr r5
mtsrr0 r3
mtsrr1 r4
RFI
KVM: PPC: Add helper functions to call real mode loaders Linux contains quite some bits of code to load FPU, Altivec and VSX lazily for a task. It calls those bits in real mode, coming from an interrupt handler. For KVM we better reuse those, so let's wrap a bit of trampoline magic around them and then we can call them from normal module code. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-15 20:49:10 +07:00
/*
* Activate current's external feature (FPU/Altivec/VSX)
*/
#define define_load_up(what) \
\
_GLOBAL(kvmppc_load_up_ ## what); \
KVM: PPC: Simplify kvmppc_load_up_(FPU|VMX|VSX) We don't need as complex code. I had some thinkos while writing it, figuring I needed to support PPC32 paths on PPC64 which would have required DR=0, but everything just runs fine with DR=1. So let's make the functions simple C call wrappers that reserve some space on the stack for the respective functions to clobber. Fixes out-of-RMA-access (and thus guest FPU loading) on the PS3. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-02-19 17:00:47 +07:00
stdu r1, -INT_FRAME_SIZE(r1); \
KVM: PPC: Add helper functions to call real mode loaders Linux contains quite some bits of code to load FPU, Altivec and VSX lazily for a task. It calls those bits in real mode, coming from an interrupt handler. For KVM we better reuse those, so let's wrap a bit of trampoline magic around them and then we can call them from normal module code. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-15 20:49:10 +07:00
mflr r3; \
std r3, _LINK(r1); \
\
bl .load_up_ ## what; \
\
ld r3, _LINK(r1); \
mtlr r3; \
KVM: PPC: Simplify kvmppc_load_up_(FPU|VMX|VSX) We don't need as complex code. I had some thinkos while writing it, figuring I needed to support PPC32 paths on PPC64 which would have required DR=0, but everything just runs fine with DR=1. So let's make the functions simple C call wrappers that reserve some space on the stack for the respective functions to clobber. Fixes out-of-RMA-access (and thus guest FPU loading) on the PS3. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-02-19 17:00:47 +07:00
addi r1, r1, INT_FRAME_SIZE; \
KVM: PPC: Add helper functions to call real mode loaders Linux contains quite some bits of code to load FPU, Altivec and VSX lazily for a task. It calls those bits in real mode, coming from an interrupt handler. For KVM we better reuse those, so let's wrap a bit of trampoline magic around them and then we can call them from normal module code. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-01-15 20:49:10 +07:00
blr
define_load_up(fpu)
#ifdef CONFIG_ALTIVEC
define_load_up(altivec)
#endif
#ifdef CONFIG_VSX
define_load_up(vsx)
#endif
Add interrupt handling code Getting from host state to the guest is only half the story. We also need to return to our host context and handle whatever happened to get us out of the guest. On PowerPC every guest exit is an interrupt. So all we need to do is trap the host's interrupt handlers and get into our #VMEXIT code to handle it. PowerPCs also have a register that can add an offset to the interrupt handlers' adresses which is what the booke KVM code uses. Unfortunately that is a hypervisor ressource and we also want to be able to run KVM when we're running in an LPAR. So we have to hook into the Linux interrupt handlers. Signed-off-by: Alexander Graf <agraf@suse.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-10-30 12:47:09 +07:00
.global kvmppc_trampoline_lowmem
kvmppc_trampoline_lowmem:
.long kvmppc_handler_lowmem_trampoline - _stext
.global kvmppc_trampoline_enter
kvmppc_trampoline_enter:
.long kvmppc_handler_trampoline_enter - _stext
#include "book3s_64_slb.S"
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