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alistair23-linux/arch/powerpc/kvm/book3s_pr.c

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/*
* Copyright (C) 2009. SUSE Linux Products GmbH. All rights reserved.
*
* Authors:
* Alexander Graf <agraf@suse.de>
* Kevin Wolf <mail@kevin-wolf.de>
* Paul Mackerras <paulus@samba.org>
*
* Description:
* Functions relating to running KVM on Book 3S processors where
* we don't have access to hypervisor mode, and we run the guest
* in problem state (user mode).
*
* This file is derived from arch/powerpc/kvm/44x.c,
* by Hollis Blanchard <hollisb@us.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/kvm_host.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <asm/reg.h>
#include <asm/cputable.h>
#include <asm/cacheflush.h>
#include <linux/uaccess.h>
#include <asm/io.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu_context.h>
#include <asm/switch_to.h>
#include <asm/firmware.h>
#include <asm/setup.h>
#include <linux/gfp.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <asm/asm-prototypes.h>
#include <asm/tm.h>
#include "book3s.h"
#define CREATE_TRACE_POINTS
#include "trace_pr.h"
/* #define EXIT_DEBUG */
/* #define DEBUG_EXT */
static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
ulong msr);
#ifdef CONFIG_PPC_BOOK3S_64
static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac);
#endif
/* Some compatibility defines */
#ifdef CONFIG_PPC_BOOK3S_32
#define MSR_USER32 MSR_USER
#define MSR_USER64 MSR_USER
#define HW_PAGE_SIZE PAGE_SIZE
#define HPTE_R_M _PAGE_COHERENT
#endif
KVM: PPC: Book3S: Add hack for split real mode Today we handle split real mode by mapping both instruction and data faults into a special virtual address space that only exists during the split mode phase. This is good enough to catch 32bit Linux guests that use split real mode for copy_from/to_user. In this case we're always prefixed with 0xc0000000 for our instruction pointer and can map the user space process freely below there. However, that approach fails when we're running KVM inside of KVM. Here the 1st level last_inst reader may well be in the same virtual page as a 2nd level interrupt handler. It also fails when running Mac OS X guests. Here we have a 4G/4G split, so a kernel copy_from/to_user implementation can easily overlap with user space addresses. The architecturally correct way to fix this would be to implement an instruction interpreter in KVM that kicks in whenever we go into split real mode. This interpreter however would not receive a great amount of testing and be a lot of bloat for a reasonably isolated corner case. So I went back to the drawing board and tried to come up with a way to make split real mode work with a single flat address space. And then I realized that we could get away with the same trick that makes it work for Linux: Whenever we see an instruction address during split real mode that may collide, we just move it higher up the virtual address space to a place that hopefully does not collide (keep your fingers crossed!). That approach does work surprisingly well. I am able to successfully run Mac OS X guests with KVM and QEMU (no split real mode hacks like MOL) when I apply a tiny timing probe hack to QEMU. I'd say this is a win over even more broken split real mode :). Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-10 18:58:58 -06:00
static bool kvmppc_is_split_real(struct kvm_vcpu *vcpu)
{
ulong msr = kvmppc_get_msr(vcpu);
return (msr & (MSR_IR|MSR_DR)) == MSR_DR;
}
static void kvmppc_fixup_split_real(struct kvm_vcpu *vcpu)
{
ulong msr = kvmppc_get_msr(vcpu);
ulong pc = kvmppc_get_pc(vcpu);
/* We are in DR only split real mode */
if ((msr & (MSR_IR|MSR_DR)) != MSR_DR)
return;
/* We have not fixed up the guest already */
if (vcpu->arch.hflags & BOOK3S_HFLAG_SPLIT_HACK)
return;
/* The code is in fixupable address space */
if (pc & SPLIT_HACK_MASK)
return;
vcpu->arch.hflags |= BOOK3S_HFLAG_SPLIT_HACK;
kvmppc_set_pc(vcpu, pc | SPLIT_HACK_OFFS);
}
void kvmppc_unfixup_split_real(struct kvm_vcpu *vcpu);
static void kvmppc_core_vcpu_load_pr(struct kvm_vcpu *vcpu, int cpu)
{
#ifdef CONFIG_PPC_BOOK3S_64
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
memcpy(svcpu->slb, to_book3s(vcpu)->slb_shadow, sizeof(svcpu->slb));
svcpu->slb_max = to_book3s(vcpu)->slb_shadow_max;
svcpu->in_use = 0;
svcpu_put(svcpu);
#endif
/* Disable AIL if supported */
if (cpu_has_feature(CPU_FTR_HVMODE) &&
cpu_has_feature(CPU_FTR_ARCH_207S))
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~LPCR_AIL);
vcpu->cpu = smp_processor_id();
#ifdef CONFIG_PPC_BOOK3S_32
current->thread.kvm_shadow_vcpu = vcpu->arch.shadow_vcpu;
#endif
KVM: PPC: Book3S: Add hack for split real mode Today we handle split real mode by mapping both instruction and data faults into a special virtual address space that only exists during the split mode phase. This is good enough to catch 32bit Linux guests that use split real mode for copy_from/to_user. In this case we're always prefixed with 0xc0000000 for our instruction pointer and can map the user space process freely below there. However, that approach fails when we're running KVM inside of KVM. Here the 1st level last_inst reader may well be in the same virtual page as a 2nd level interrupt handler. It also fails when running Mac OS X guests. Here we have a 4G/4G split, so a kernel copy_from/to_user implementation can easily overlap with user space addresses. The architecturally correct way to fix this would be to implement an instruction interpreter in KVM that kicks in whenever we go into split real mode. This interpreter however would not receive a great amount of testing and be a lot of bloat for a reasonably isolated corner case. So I went back to the drawing board and tried to come up with a way to make split real mode work with a single flat address space. And then I realized that we could get away with the same trick that makes it work for Linux: Whenever we see an instruction address during split real mode that may collide, we just move it higher up the virtual address space to a place that hopefully does not collide (keep your fingers crossed!). That approach does work surprisingly well. I am able to successfully run Mac OS X guests with KVM and QEMU (no split real mode hacks like MOL) when I apply a tiny timing probe hack to QEMU. I'd say this is a win over even more broken split real mode :). Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-10 18:58:58 -06:00
if (kvmppc_is_split_real(vcpu))
kvmppc_fixup_split_real(vcpu);
kvmppc_restore_tm_pr(vcpu);
}
static void kvmppc_core_vcpu_put_pr(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_PPC_BOOK3S_64
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
if (svcpu->in_use) {
kvmppc_copy_from_svcpu(vcpu);
}
memcpy(to_book3s(vcpu)->slb_shadow, svcpu->slb, sizeof(svcpu->slb));
to_book3s(vcpu)->slb_shadow_max = svcpu->slb_max;
svcpu_put(svcpu);
#endif
KVM: PPC: Book3S: Add hack for split real mode Today we handle split real mode by mapping both instruction and data faults into a special virtual address space that only exists during the split mode phase. This is good enough to catch 32bit Linux guests that use split real mode for copy_from/to_user. In this case we're always prefixed with 0xc0000000 for our instruction pointer and can map the user space process freely below there. However, that approach fails when we're running KVM inside of KVM. Here the 1st level last_inst reader may well be in the same virtual page as a 2nd level interrupt handler. It also fails when running Mac OS X guests. Here we have a 4G/4G split, so a kernel copy_from/to_user implementation can easily overlap with user space addresses. The architecturally correct way to fix this would be to implement an instruction interpreter in KVM that kicks in whenever we go into split real mode. This interpreter however would not receive a great amount of testing and be a lot of bloat for a reasonably isolated corner case. So I went back to the drawing board and tried to come up with a way to make split real mode work with a single flat address space. And then I realized that we could get away with the same trick that makes it work for Linux: Whenever we see an instruction address during split real mode that may collide, we just move it higher up the virtual address space to a place that hopefully does not collide (keep your fingers crossed!). That approach does work surprisingly well. I am able to successfully run Mac OS X guests with KVM and QEMU (no split real mode hacks like MOL) when I apply a tiny timing probe hack to QEMU. I'd say this is a win over even more broken split real mode :). Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-10 18:58:58 -06:00
if (kvmppc_is_split_real(vcpu))
kvmppc_unfixup_split_real(vcpu);
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
kvmppc_giveup_ext(vcpu, MSR_FP | MSR_VEC | MSR_VSX);
kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
kvmppc_save_tm_pr(vcpu);
/* Enable AIL if supported */
if (cpu_has_feature(CPU_FTR_HVMODE) &&
cpu_has_feature(CPU_FTR_ARCH_207S))
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_AIL_3);
vcpu->cpu = -1;
}
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
/* Copy data needed by real-mode code from vcpu to shadow vcpu */
void kvmppc_copy_to_svcpu(struct kvm_vcpu *vcpu)
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
{
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
svcpu->gpr[0] = vcpu->arch.regs.gpr[0];
svcpu->gpr[1] = vcpu->arch.regs.gpr[1];
svcpu->gpr[2] = vcpu->arch.regs.gpr[2];
svcpu->gpr[3] = vcpu->arch.regs.gpr[3];
svcpu->gpr[4] = vcpu->arch.regs.gpr[4];
svcpu->gpr[5] = vcpu->arch.regs.gpr[5];
svcpu->gpr[6] = vcpu->arch.regs.gpr[6];
svcpu->gpr[7] = vcpu->arch.regs.gpr[7];
svcpu->gpr[8] = vcpu->arch.regs.gpr[8];
svcpu->gpr[9] = vcpu->arch.regs.gpr[9];
svcpu->gpr[10] = vcpu->arch.regs.gpr[10];
svcpu->gpr[11] = vcpu->arch.regs.gpr[11];
svcpu->gpr[12] = vcpu->arch.regs.gpr[12];
svcpu->gpr[13] = vcpu->arch.regs.gpr[13];
svcpu->cr = vcpu->arch.regs.ccr;
svcpu->xer = vcpu->arch.regs.xer;
svcpu->ctr = vcpu->arch.regs.ctr;
svcpu->lr = vcpu->arch.regs.link;
svcpu->pc = vcpu->arch.regs.nip;
#ifdef CONFIG_PPC_BOOK3S_64
svcpu->shadow_fscr = vcpu->arch.shadow_fscr;
#endif
/*
* Now also save the current time base value. We use this
* to find the guest purr and spurr value.
*/
vcpu->arch.entry_tb = get_tb();
vcpu->arch.entry_vtb = get_vtb();
if (cpu_has_feature(CPU_FTR_ARCH_207S))
vcpu->arch.entry_ic = mfspr(SPRN_IC);
svcpu->in_use = true;
svcpu_put(svcpu);
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
}
static void kvmppc_recalc_shadow_msr(struct kvm_vcpu *vcpu)
{
ulong guest_msr = kvmppc_get_msr(vcpu);
ulong smsr = guest_msr;
/* Guest MSR values */
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
smsr &= MSR_FE0 | MSR_FE1 | MSR_SF | MSR_SE | MSR_BE | MSR_LE |
MSR_TM | MSR_TS_MASK;
#else
smsr &= MSR_FE0 | MSR_FE1 | MSR_SF | MSR_SE | MSR_BE | MSR_LE;
#endif
/* Process MSR values */
smsr |= MSR_ME | MSR_RI | MSR_IR | MSR_DR | MSR_PR | MSR_EE;
/* External providers the guest reserved */
smsr |= (guest_msr & vcpu->arch.guest_owned_ext);
/* 64-bit Process MSR values */
#ifdef CONFIG_PPC_BOOK3S_64
smsr |= MSR_ISF | MSR_HV;
#endif
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/*
* in guest privileged state, we want to fail all TM transactions.
* So disable MSR TM bit so that all tbegin. will be able to be
* trapped into host.
*/
if (!(guest_msr & MSR_PR))
smsr &= ~MSR_TM;
#endif
vcpu->arch.shadow_msr = smsr;
}
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
/* Copy data touched by real-mode code from shadow vcpu back to vcpu */
void kvmppc_copy_from_svcpu(struct kvm_vcpu *vcpu)
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
{
struct kvmppc_book3s_shadow_vcpu *svcpu = svcpu_get(vcpu);
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
ulong old_msr;
#endif
/*
* Maybe we were already preempted and synced the svcpu from
* our preempt notifiers. Don't bother touching this svcpu then.
*/
if (!svcpu->in_use)
goto out;
vcpu->arch.regs.gpr[0] = svcpu->gpr[0];
vcpu->arch.regs.gpr[1] = svcpu->gpr[1];
vcpu->arch.regs.gpr[2] = svcpu->gpr[2];
vcpu->arch.regs.gpr[3] = svcpu->gpr[3];
vcpu->arch.regs.gpr[4] = svcpu->gpr[4];
vcpu->arch.regs.gpr[5] = svcpu->gpr[5];
vcpu->arch.regs.gpr[6] = svcpu->gpr[6];
vcpu->arch.regs.gpr[7] = svcpu->gpr[7];
vcpu->arch.regs.gpr[8] = svcpu->gpr[8];
vcpu->arch.regs.gpr[9] = svcpu->gpr[9];
vcpu->arch.regs.gpr[10] = svcpu->gpr[10];
vcpu->arch.regs.gpr[11] = svcpu->gpr[11];
vcpu->arch.regs.gpr[12] = svcpu->gpr[12];
vcpu->arch.regs.gpr[13] = svcpu->gpr[13];
vcpu->arch.regs.ccr = svcpu->cr;
vcpu->arch.regs.xer = svcpu->xer;
vcpu->arch.regs.ctr = svcpu->ctr;
vcpu->arch.regs.link = svcpu->lr;
vcpu->arch.regs.nip = svcpu->pc;
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
vcpu->arch.shadow_srr1 = svcpu->shadow_srr1;
vcpu->arch.fault_dar = svcpu->fault_dar;
vcpu->arch.fault_dsisr = svcpu->fault_dsisr;
vcpu->arch.last_inst = svcpu->last_inst;
#ifdef CONFIG_PPC_BOOK3S_64
vcpu->arch.shadow_fscr = svcpu->shadow_fscr;
#endif
/*
* Update purr and spurr using time base on exit.
*/
vcpu->arch.purr += get_tb() - vcpu->arch.entry_tb;
vcpu->arch.spurr += get_tb() - vcpu->arch.entry_tb;
to_book3s(vcpu)->vtb += get_vtb() - vcpu->arch.entry_vtb;
if (cpu_has_feature(CPU_FTR_ARCH_207S))
vcpu->arch.ic += mfspr(SPRN_IC) - vcpu->arch.entry_ic;
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/*
* Unlike other MSR bits, MSR[TS]bits can be changed at guest without
* notifying host:
* modified by unprivileged instructions like "tbegin"/"tend"/
* "tresume"/"tsuspend" in PR KVM guest.
*
* It is necessary to sync here to calculate a correct shadow_msr.
*
* privileged guest's tbegin will be failed at present. So we
* only take care of problem state guest.
*/
old_msr = kvmppc_get_msr(vcpu);
if (unlikely((old_msr & MSR_PR) &&
(vcpu->arch.shadow_srr1 & (MSR_TS_MASK)) !=
(old_msr & (MSR_TS_MASK)))) {
old_msr &= ~(MSR_TS_MASK);
old_msr |= (vcpu->arch.shadow_srr1 & (MSR_TS_MASK));
kvmppc_set_msr_fast(vcpu, old_msr);
kvmppc_recalc_shadow_msr(vcpu);
}
#endif
svcpu->in_use = false;
out:
svcpu_put(svcpu);
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
}
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
void kvmppc_save_tm_sprs(struct kvm_vcpu *vcpu)
{
tm_enable();
vcpu->arch.tfhar = mfspr(SPRN_TFHAR);
vcpu->arch.texasr = mfspr(SPRN_TEXASR);
vcpu->arch.tfiar = mfspr(SPRN_TFIAR);
tm_disable();
}
void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu)
{
tm_enable();
mtspr(SPRN_TFHAR, vcpu->arch.tfhar);
mtspr(SPRN_TEXASR, vcpu->arch.texasr);
mtspr(SPRN_TFIAR, vcpu->arch.tfiar);
tm_disable();
}
/* loadup math bits which is enabled at kvmppc_get_msr() but not enabled at
* hardware.
*/
static void kvmppc_handle_lost_math_exts(struct kvm_vcpu *vcpu)
{
ulong exit_nr;
ulong ext_diff = (kvmppc_get_msr(vcpu) & ~vcpu->arch.guest_owned_ext) &
(MSR_FP | MSR_VEC | MSR_VSX);
if (!ext_diff)
return;
if (ext_diff == MSR_FP)
exit_nr = BOOK3S_INTERRUPT_FP_UNAVAIL;
else if (ext_diff == MSR_VEC)
exit_nr = BOOK3S_INTERRUPT_ALTIVEC;
else
exit_nr = BOOK3S_INTERRUPT_VSX;
kvmppc_handle_ext(vcpu, exit_nr, ext_diff);
}
void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu)
{
if (!(MSR_TM_ACTIVE(kvmppc_get_msr(vcpu)))) {
kvmppc_save_tm_sprs(vcpu);
return;
}
kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
kvmppc_giveup_ext(vcpu, MSR_VSX);
preempt_disable();
_kvmppc_save_tm_pr(vcpu, mfmsr());
preempt_enable();
}
void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu)
{
if (!MSR_TM_ACTIVE(kvmppc_get_msr(vcpu))) {
kvmppc_restore_tm_sprs(vcpu);
if (kvmppc_get_msr(vcpu) & MSR_TM) {
kvmppc_handle_lost_math_exts(vcpu);
if (vcpu->arch.fscr & FSCR_TAR)
kvmppc_handle_fac(vcpu, FSCR_TAR_LG);
}
return;
}
preempt_disable();
_kvmppc_restore_tm_pr(vcpu, kvmppc_get_msr(vcpu));
preempt_enable();
if (kvmppc_get_msr(vcpu) & MSR_TM) {
kvmppc_handle_lost_math_exts(vcpu);
if (vcpu->arch.fscr & FSCR_TAR)
kvmppc_handle_fac(vcpu, FSCR_TAR_LG);
}
}
#endif
static int kvmppc_core_check_requests_pr(struct kvm_vcpu *vcpu)
{
int r = 1; /* Indicate we want to get back into the guest */
/* We misuse TLB_FLUSH to indicate that we want to clear
all shadow cache entries */
if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu))
kvmppc_mmu_pte_flush(vcpu, 0, 0);
return r;
}
/************* MMU Notifiers *************/
static void do_kvm_unmap_hva(struct kvm *kvm, unsigned long start,
unsigned long end)
{
long i;
struct kvm_vcpu *vcpu;
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
slots = kvm_memslots(kvm);
kvm_for_each_memslot(memslot, slots) {
unsigned long hva_start, hva_end;
gfn_t gfn, gfn_end;
hva_start = max(start, memslot->userspace_addr);
hva_end = min(end, memslot->userspace_addr +
(memslot->npages << PAGE_SHIFT));
if (hva_start >= hva_end)
continue;
/*
* {gfn(page) | page intersects with [hva_start, hva_end)} =
* {gfn, gfn+1, ..., gfn_end-1}.
*/
gfn = hva_to_gfn_memslot(hva_start, memslot);
gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
kvm_for_each_vcpu(i, vcpu, kvm)
kvmppc_mmu_pte_pflush(vcpu, gfn << PAGE_SHIFT,
gfn_end << PAGE_SHIFT);
}
}
static int kvm_unmap_hva_range_pr(struct kvm *kvm, unsigned long start,
unsigned long end)
{
do_kvm_unmap_hva(kvm, start, end);
return 0;
}
static int kvm_age_hva_pr(struct kvm *kvm, unsigned long start,
unsigned long end)
{
/* XXX could be more clever ;) */
return 0;
}
static int kvm_test_age_hva_pr(struct kvm *kvm, unsigned long hva)
{
/* XXX could be more clever ;) */
return 0;
}
static void kvm_set_spte_hva_pr(struct kvm *kvm, unsigned long hva, pte_t pte)
{
/* The page will get remapped properly on its next fault */
do_kvm_unmap_hva(kvm, hva, hva + PAGE_SIZE);
}
/*****************************************/
static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr)
{
ulong old_msr;
/* For PAPR guest, make sure MSR reflects guest mode */
if (vcpu->arch.papr_enabled)
msr = (msr & ~MSR_HV) | MSR_ME;
#ifdef EXIT_DEBUG
printk(KERN_INFO "KVM: Set MSR to 0x%llx\n", msr);
#endif
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* We should never target guest MSR to TS=10 && PR=0,
* since we always fail transaction for guest privilege
* state.
*/
if (!(msr & MSR_PR) && MSR_TM_TRANSACTIONAL(msr))
kvmppc_emulate_tabort(vcpu,
TM_CAUSE_KVM_FAC_UNAV | TM_CAUSE_PERSISTENT);
#endif
old_msr = kvmppc_get_msr(vcpu);
msr &= to_book3s(vcpu)->msr_mask;
kvmppc_set_msr_fast(vcpu, msr);
kvmppc_recalc_shadow_msr(vcpu);
if (msr & MSR_POW) {
if (!vcpu->arch.pending_exceptions) {
kvm_vcpu_block(vcpu);
kvm_clear_request(KVM_REQ_UNHALT, vcpu);
vcpu->stat.halt_wakeup++;
/* Unset POW bit after we woke up */
msr &= ~MSR_POW;
kvmppc_set_msr_fast(vcpu, msr);
}
}
KVM: PPC: Book3S: Add hack for split real mode Today we handle split real mode by mapping both instruction and data faults into a special virtual address space that only exists during the split mode phase. This is good enough to catch 32bit Linux guests that use split real mode for copy_from/to_user. In this case we're always prefixed with 0xc0000000 for our instruction pointer and can map the user space process freely below there. However, that approach fails when we're running KVM inside of KVM. Here the 1st level last_inst reader may well be in the same virtual page as a 2nd level interrupt handler. It also fails when running Mac OS X guests. Here we have a 4G/4G split, so a kernel copy_from/to_user implementation can easily overlap with user space addresses. The architecturally correct way to fix this would be to implement an instruction interpreter in KVM that kicks in whenever we go into split real mode. This interpreter however would not receive a great amount of testing and be a lot of bloat for a reasonably isolated corner case. So I went back to the drawing board and tried to come up with a way to make split real mode work with a single flat address space. And then I realized that we could get away with the same trick that makes it work for Linux: Whenever we see an instruction address during split real mode that may collide, we just move it higher up the virtual address space to a place that hopefully does not collide (keep your fingers crossed!). That approach does work surprisingly well. I am able to successfully run Mac OS X guests with KVM and QEMU (no split real mode hacks like MOL) when I apply a tiny timing probe hack to QEMU. I'd say this is a win over even more broken split real mode :). Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-10 18:58:58 -06:00
if (kvmppc_is_split_real(vcpu))
kvmppc_fixup_split_real(vcpu);
else
kvmppc_unfixup_split_real(vcpu);
if ((kvmppc_get_msr(vcpu) & (MSR_PR|MSR_IR|MSR_DR)) !=
(old_msr & (MSR_PR|MSR_IR|MSR_DR))) {
kvmppc_mmu_flush_segments(vcpu);
kvmppc_mmu_map_segment(vcpu, kvmppc_get_pc(vcpu));
/* Preload magic page segment when in kernel mode */
if (!(msr & MSR_PR) && vcpu->arch.magic_page_pa) {
struct kvm_vcpu_arch *a = &vcpu->arch;
if (msr & MSR_DR)
kvmppc_mmu_map_segment(vcpu, a->magic_page_ea);
else
kvmppc_mmu_map_segment(vcpu, a->magic_page_pa);
}
}
/*
* When switching from 32 to 64-bit, we may have a stale 32-bit
* magic page around, we need to flush it. Typically 32-bit magic
* page will be instantiated when calling into RTAS. Note: We
* assume that such transition only happens while in kernel mode,
* ie, we never transition from user 32-bit to kernel 64-bit with
* a 32-bit magic page around.
*/
if (vcpu->arch.magic_page_pa &&
!(old_msr & MSR_PR) && !(old_msr & MSR_SF) && (msr & MSR_SF)) {
/* going from RTAS to normal kernel code */
kvmppc_mmu_pte_flush(vcpu, (uint32_t)vcpu->arch.magic_page_pa,
~0xFFFUL);
}
/* Preload FPU if it's enabled */
if (kvmppc_get_msr(vcpu) & MSR_FP)
kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
if (kvmppc_get_msr(vcpu) & MSR_TM)
kvmppc_handle_lost_math_exts(vcpu);
#endif
}
void kvmppc_set_pvr_pr(struct kvm_vcpu *vcpu, u32 pvr)
{
u32 host_pvr;
vcpu->arch.hflags &= ~BOOK3S_HFLAG_SLB;
vcpu->arch.pvr = pvr;
#ifdef CONFIG_PPC_BOOK3S_64
if ((pvr >= 0x330000) && (pvr < 0x70330000)) {
kvmppc_mmu_book3s_64_init(vcpu);
if (!to_book3s(vcpu)->hior_explicit)
to_book3s(vcpu)->hior = 0xfff00000;
to_book3s(vcpu)->msr_mask = 0xffffffffffffffffULL;
vcpu->arch.cpu_type = KVM_CPU_3S_64;
} else
#endif
{
kvmppc_mmu_book3s_32_init(vcpu);
if (!to_book3s(vcpu)->hior_explicit)
to_book3s(vcpu)->hior = 0;
to_book3s(vcpu)->msr_mask = 0xffffffffULL;
vcpu->arch.cpu_type = KVM_CPU_3S_32;
}
kvmppc_sanity_check(vcpu);
/* If we are in hypervisor level on 970, we can tell the CPU to
* treat DCBZ as 32 bytes store */
vcpu->arch.hflags &= ~BOOK3S_HFLAG_DCBZ32;
if (vcpu->arch.mmu.is_dcbz32(vcpu) && (mfmsr() & MSR_HV) &&
!strcmp(cur_cpu_spec->platform, "ppc970"))
vcpu->arch.hflags |= BOOK3S_HFLAG_DCBZ32;
/* Cell performs badly if MSR_FEx are set. So let's hope nobody
really needs them in a VM on Cell and force disable them. */
if (!strcmp(cur_cpu_spec->platform, "ppc-cell-be"))
to_book3s(vcpu)->msr_mask &= ~(MSR_FE0 | MSR_FE1);
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
/*
* If they're asking for POWER6 or later, set the flag
* indicating that we can do multiple large page sizes
* and 1TB segments.
* Also set the flag that indicates that tlbie has the large
* page bit in the RB operand instead of the instruction.
*/
switch (PVR_VER(pvr)) {
case PVR_POWER6:
case PVR_POWER7:
case PVR_POWER7p:
case PVR_POWER8:
case PVR_POWER8E:
case PVR_POWER8NVL:
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
vcpu->arch.hflags |= BOOK3S_HFLAG_MULTI_PGSIZE |
BOOK3S_HFLAG_NEW_TLBIE;
break;
}
#ifdef CONFIG_PPC_BOOK3S_32
/* 32 bit Book3S always has 32 byte dcbz */
vcpu->arch.hflags |= BOOK3S_HFLAG_DCBZ32;
#endif
/* On some CPUs we can execute paired single operations natively */
asm ( "mfpvr %0" : "=r"(host_pvr));
switch (host_pvr) {
case 0x00080200: /* lonestar 2.0 */
case 0x00088202: /* lonestar 2.2 */
case 0x70000100: /* gekko 1.0 */
case 0x00080100: /* gekko 2.0 */
case 0x00083203: /* gekko 2.3a */
case 0x00083213: /* gekko 2.3b */
case 0x00083204: /* gekko 2.4 */
case 0x00083214: /* gekko 2.4e (8SE) - retail HW2 */
case 0x00087200: /* broadway */
vcpu->arch.hflags |= BOOK3S_HFLAG_NATIVE_PS;
/* Enable HID2.PSE - in case we need it later */
mtspr(SPRN_HID2_GEKKO, mfspr(SPRN_HID2_GEKKO) | (1 << 29));
}
}
/* Book3s_32 CPUs always have 32 bytes cache line size, which Linux assumes. To
* make Book3s_32 Linux work on Book3s_64, we have to make sure we trap dcbz to
* emulate 32 bytes dcbz length.
*
* The Book3s_64 inventors also realized this case and implemented a special bit
* in the HID5 register, which is a hypervisor ressource. Thus we can't use it.
*
* My approach here is to patch the dcbz instruction on executing pages.
*/
static void kvmppc_patch_dcbz(struct kvm_vcpu *vcpu, struct kvmppc_pte *pte)
{
struct page *hpage;
u64 hpage_offset;
u32 *page;
int i;
hpage = gfn_to_page(vcpu->kvm, pte->raddr >> PAGE_SHIFT);
if (is_error_page(hpage))
return;
hpage_offset = pte->raddr & ~PAGE_MASK;
hpage_offset &= ~0xFFFULL;
hpage_offset /= 4;
get_page(hpage);
page = kmap_atomic(hpage);
/* patch dcbz into reserved instruction, so we trap */
for (i=hpage_offset; i < hpage_offset + (HW_PAGE_SIZE / 4); i++)
if ((be32_to_cpu(page[i]) & 0xff0007ff) == INS_DCBZ)
page[i] &= cpu_to_be32(0xfffffff7);
kunmap_atomic(page);
put_page(hpage);
}
static bool kvmppc_visible_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
{
ulong mp_pa = vcpu->arch.magic_page_pa;
if (!(kvmppc_get_msr(vcpu) & MSR_SF))
mp_pa = (uint32_t)mp_pa;
gpa &= ~0xFFFULL;
if (unlikely(mp_pa) && unlikely((mp_pa & KVM_PAM) == (gpa & KVM_PAM))) {
return true;
}
return kvm_is_visible_gfn(vcpu->kvm, gpa >> PAGE_SHIFT);
}
int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu,
ulong eaddr, int vec)
{
bool data = (vec == BOOK3S_INTERRUPT_DATA_STORAGE);
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
bool iswrite = false;
int r = RESUME_GUEST;
int relocated;
int page_found = 0;
struct kvmppc_pte pte = { 0 };
bool dr = (kvmppc_get_msr(vcpu) & MSR_DR) ? true : false;
bool ir = (kvmppc_get_msr(vcpu) & MSR_IR) ? true : false;
u64 vsid;
relocated = data ? dr : ir;
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
if (data && (vcpu->arch.fault_dsisr & DSISR_ISSTORE))
iswrite = true;
/* Resolve real address if translation turned on */
if (relocated) {
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
page_found = vcpu->arch.mmu.xlate(vcpu, eaddr, &pte, data, iswrite);
} else {
pte.may_execute = true;
pte.may_read = true;
pte.may_write = true;
pte.raddr = eaddr & KVM_PAM;
pte.eaddr = eaddr;
pte.vpage = eaddr >> 12;
pte.page_size = MMU_PAGE_64K;
pte.wimg = HPTE_R_M;
}
switch (kvmppc_get_msr(vcpu) & (MSR_DR|MSR_IR)) {
case 0:
pte.vpage |= ((u64)VSID_REAL << (SID_SHIFT - 12));
break;
case MSR_DR:
KVM: PPC: Book3S: Add hack for split real mode Today we handle split real mode by mapping both instruction and data faults into a special virtual address space that only exists during the split mode phase. This is good enough to catch 32bit Linux guests that use split real mode for copy_from/to_user. In this case we're always prefixed with 0xc0000000 for our instruction pointer and can map the user space process freely below there. However, that approach fails when we're running KVM inside of KVM. Here the 1st level last_inst reader may well be in the same virtual page as a 2nd level interrupt handler. It also fails when running Mac OS X guests. Here we have a 4G/4G split, so a kernel copy_from/to_user implementation can easily overlap with user space addresses. The architecturally correct way to fix this would be to implement an instruction interpreter in KVM that kicks in whenever we go into split real mode. This interpreter however would not receive a great amount of testing and be a lot of bloat for a reasonably isolated corner case. So I went back to the drawing board and tried to come up with a way to make split real mode work with a single flat address space. And then I realized that we could get away with the same trick that makes it work for Linux: Whenever we see an instruction address during split real mode that may collide, we just move it higher up the virtual address space to a place that hopefully does not collide (keep your fingers crossed!). That approach does work surprisingly well. I am able to successfully run Mac OS X guests with KVM and QEMU (no split real mode hacks like MOL) when I apply a tiny timing probe hack to QEMU. I'd say this is a win over even more broken split real mode :). Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-10 18:58:58 -06:00
if (!data &&
(vcpu->arch.hflags & BOOK3S_HFLAG_SPLIT_HACK) &&
((pte.raddr & SPLIT_HACK_MASK) == SPLIT_HACK_OFFS))
pte.raddr &= ~SPLIT_HACK_MASK;
/* fall through */
case MSR_IR:
vcpu->arch.mmu.esid_to_vsid(vcpu, eaddr >> SID_SHIFT, &vsid);
if ((kvmppc_get_msr(vcpu) & (MSR_DR|MSR_IR)) == MSR_DR)
pte.vpage |= ((u64)VSID_REAL_DR << (SID_SHIFT - 12));
else
pte.vpage |= ((u64)VSID_REAL_IR << (SID_SHIFT - 12));
pte.vpage |= vsid;
if (vsid == -1)
page_found = -EINVAL;
break;
}
if (vcpu->arch.mmu.is_dcbz32(vcpu) &&
(!(vcpu->arch.hflags & BOOK3S_HFLAG_DCBZ32))) {
/*
* If we do the dcbz hack, we have to NX on every execution,
* so we can patch the executing code. This renders our guest
* NX-less.
*/
pte.may_execute = !data;
}
if (page_found == -ENOENT || page_found == -EPERM) {
/* Page not found in guest PTE entries, or protection fault */
u64 flags;
if (page_found == -EPERM)
flags = DSISR_PROTFAULT;
else
flags = DSISR_NOHPTE;
if (data) {
flags |= vcpu->arch.fault_dsisr & DSISR_ISSTORE;
kvmppc_core_queue_data_storage(vcpu, eaddr, flags);
} else {
kvmppc_core_queue_inst_storage(vcpu, flags);
}
} else if (page_found == -EINVAL) {
/* Page not found in guest SLB */
kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu));
kvmppc_book3s_queue_irqprio(vcpu, vec + 0x80);
} else if (kvmppc_visible_gpa(vcpu, pte.raddr)) {
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
if (data && !(vcpu->arch.fault_dsisr & DSISR_NOHPTE)) {
/*
* There is already a host HPTE there, presumably
* a read-only one for a page the guest thinks
* is writable, so get rid of it first.
*/
kvmppc_mmu_unmap_page(vcpu, &pte);
}
/* The guest's PTE is not mapped yet. Map on the host */
if (kvmppc_mmu_map_page(vcpu, &pte, iswrite) == -EIO) {
/* Exit KVM if mapping failed */
run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
return RESUME_HOST;
}
if (data)
vcpu->stat.sp_storage++;
else if (vcpu->arch.mmu.is_dcbz32(vcpu) &&
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
(!(vcpu->arch.hflags & BOOK3S_HFLAG_DCBZ32)))
kvmppc_patch_dcbz(vcpu, &pte);
} else {
/* MMIO */
vcpu->stat.mmio_exits++;
vcpu->arch.paddr_accessed = pte.raddr;
vcpu->arch.vaddr_accessed = pte.eaddr;
r = kvmppc_emulate_mmio(run, vcpu);
if ( r == RESUME_HOST_NV )
r = RESUME_HOST;
}
return r;
}
/* Give up external provider (FPU, Altivec, VSX) */
void kvmppc_giveup_ext(struct kvm_vcpu *vcpu, ulong msr)
{
struct thread_struct *t = &current->thread;
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
/*
* VSX instructions can access FP and vector registers, so if
* we are giving up VSX, make sure we give up FP and VMX as well.
*/
if (msr & MSR_VSX)
msr |= MSR_FP | MSR_VEC;
msr &= vcpu->arch.guest_owned_ext;
if (!msr)
return;
#ifdef DEBUG_EXT
printk(KERN_INFO "Giving up ext 0x%lx\n", msr);
#endif
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
if (msr & MSR_FP) {
/*
* Note that on CPUs with VSX, giveup_fpu stores
* both the traditional FP registers and the added VSX
* registers into thread.fp_state.fpr[].
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
*/
if (t->regs->msr & MSR_FP)
giveup_fpu(current);
t->fp_save_area = NULL;
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
}
#ifdef CONFIG_ALTIVEC
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
if (msr & MSR_VEC) {
if (current->thread.regs->msr & MSR_VEC)
giveup_altivec(current);
t->vr_save_area = NULL;
}
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
#endif
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
vcpu->arch.guest_owned_ext &= ~(msr | MSR_VSX);
kvmppc_recalc_shadow_msr(vcpu);
}
/* Give up facility (TAR / EBB / DSCR) */
void kvmppc_giveup_fac(struct kvm_vcpu *vcpu, ulong fac)
{
#ifdef CONFIG_PPC_BOOK3S_64
if (!(vcpu->arch.shadow_fscr & (1ULL << fac))) {
/* Facility not available to the guest, ignore giveup request*/
return;
}
switch (fac) {
case FSCR_TAR_LG:
vcpu->arch.tar = mfspr(SPRN_TAR);
mtspr(SPRN_TAR, current->thread.tar);
vcpu->arch.shadow_fscr &= ~FSCR_TAR;
break;
}
#endif
}
/* Handle external providers (FPU, Altivec, VSX) */
static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr,
ulong msr)
{
struct thread_struct *t = &current->thread;
/* When we have paired singles, we emulate in software */
if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE)
return RESUME_GUEST;
if (!(kvmppc_get_msr(vcpu) & msr)) {
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
return RESUME_GUEST;
}
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
if (msr == MSR_VSX) {
/* No VSX? Give an illegal instruction interrupt */
#ifdef CONFIG_VSX
if (!cpu_has_feature(CPU_FTR_VSX))
#endif
{
kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
return RESUME_GUEST;
}
/*
* We have to load up all the FP and VMX registers before
* we can let the guest use VSX instructions.
*/
msr = MSR_FP | MSR_VEC | MSR_VSX;
}
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
/* See if we already own all the ext(s) needed */
msr &= ~vcpu->arch.guest_owned_ext;
if (!msr)
return RESUME_GUEST;
#ifdef DEBUG_EXT
printk(KERN_INFO "Loading up ext 0x%lx\n", msr);
#endif
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
if (msr & MSR_FP) {
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_disable();
enable_kernel_fp();
load_fp_state(&vcpu->arch.fp);
disable_kernel_fp();
t->fp_save_area = &vcpu->arch.fp;
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_enable();
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
}
if (msr & MSR_VEC) {
#ifdef CONFIG_ALTIVEC
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_disable();
enable_kernel_altivec();
load_vr_state(&vcpu->arch.vr);
disable_kernel_altivec();
t->vr_save_area = &vcpu->arch.vr;
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_enable();
#endif
}
t->regs->msr |= msr;
vcpu->arch.guest_owned_ext |= msr;
kvmppc_recalc_shadow_msr(vcpu);
return RESUME_GUEST;
}
/*
* Kernel code using FP or VMX could have flushed guest state to
* the thread_struct; if so, get it back now.
*/
static void kvmppc_handle_lost_ext(struct kvm_vcpu *vcpu)
{
unsigned long lost_ext;
lost_ext = vcpu->arch.guest_owned_ext & ~current->thread.regs->msr;
if (!lost_ext)
return;
if (lost_ext & MSR_FP) {
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_disable();
enable_kernel_fp();
load_fp_state(&vcpu->arch.fp);
disable_kernel_fp();
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_enable();
}
#ifdef CONFIG_ALTIVEC
if (lost_ext & MSR_VEC) {
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_disable();
enable_kernel_altivec();
load_vr_state(&vcpu->arch.vr);
disable_kernel_altivec();
KVM: PPC: BOOK3S: PR: Fix WARN_ON with debug options on With debug option "sleep inside atomic section checking" enabled we get the below WARN_ON during a PR KVM boot. This is because upstream now have PREEMPT_COUNT enabled even if we have preempt disabled. Fix the warning by adding preempt_disable/enable around floating point and altivec enable. WARNING: at arch/powerpc/kernel/process.c:156 Modules linked in: kvm_pr kvm CPU: 1 PID: 3990 Comm: qemu-system-ppc Tainted: G W 3.15.0-rc1+ #4 task: c0000000eb85b3a0 ti: c0000000ec59c000 task.ti: c0000000ec59c000 NIP: c000000000015c84 LR: d000000003334644 CTR: c000000000015c00 REGS: c0000000ec59f140 TRAP: 0700 Tainted: G W (3.15.0-rc1+) MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI> CR: 42000024 XER: 20000000 CFAR: c000000000015c24 SOFTE: 1 GPR00: d000000003334644 c0000000ec59f3c0 c000000000e2fa40 c0000000e2f80000 GPR04: 0000000000000800 0000000000002000 0000000000000001 8000000000000000 GPR08: 0000000000000001 0000000000000001 0000000000002000 c000000000015c00 GPR12: d00000000333da18 c00000000fb80900 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 00003fffce4e0fa1 GPR20: 0000000000000010 0000000000000001 0000000000000002 00000000100b9a38 GPR24: 0000000000000002 0000000000000000 0000000000000000 0000000000000013 GPR28: 0000000000000000 c0000000eb85b3a0 0000000000002000 c0000000e2f80000 NIP [c000000000015c84] .enable_kernel_fp+0x84/0x90 LR [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] Call Trace: [c0000000ec59f3c0] [0000000000000010] 0x10 (unreliable) [c0000000ec59f430] [d000000003334644] .kvmppc_handle_ext+0x134/0x190 [kvm_pr] [c0000000ec59f4c0] [d00000000324b380] .kvmppc_set_msr+0x30/0x50 [kvm] [c0000000ec59f530] [d000000003337cac] .kvmppc_core_emulate_op_pr+0x16c/0x5e0 [kvm_pr] [c0000000ec59f5f0] [d00000000324a944] .kvmppc_emulate_instruction+0x284/0xa80 [kvm] [c0000000ec59f6c0] [d000000003336888] .kvmppc_handle_exit_pr+0x488/0xb70 [kvm_pr] [c0000000ec59f790] [d000000003338d34] kvm_start_lightweight+0xcc/0xdc [kvm_pr] [c0000000ec59f960] [d000000003336288] .kvmppc_vcpu_run_pr+0xc8/0x190 [kvm_pr] [c0000000ec59f9f0] [d00000000324c880] .kvmppc_vcpu_run+0x30/0x50 [kvm] [c0000000ec59fa60] [d000000003249e74] .kvm_arch_vcpu_ioctl_run+0x54/0x1b0 [kvm] [c0000000ec59faf0] [d000000003244948] .kvm_vcpu_ioctl+0x478/0x760 [kvm] [c0000000ec59fcb0] [c000000000224e34] .do_vfs_ioctl+0x4d4/0x790 [c0000000ec59fd90] [c000000000225148] .SyS_ioctl+0x58/0xb0 [c0000000ec59fe30] [c00000000000a1e4] syscall_exit+0x0/0x98 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-05-04 11:26:08 -06:00
preempt_enable();
}
#endif
current->thread.regs->msr |= lost_ext;
}
#ifdef CONFIG_PPC_BOOK3S_64
void kvmppc_trigger_fac_interrupt(struct kvm_vcpu *vcpu, ulong fac)
{
/* Inject the Interrupt Cause field and trigger a guest interrupt */
vcpu->arch.fscr &= ~(0xffULL << 56);
vcpu->arch.fscr |= (fac << 56);
kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_FAC_UNAVAIL);
}
static void kvmppc_emulate_fac(struct kvm_vcpu *vcpu, ulong fac)
{
enum emulation_result er = EMULATE_FAIL;
if (!(kvmppc_get_msr(vcpu) & MSR_PR))
er = kvmppc_emulate_instruction(vcpu->run, vcpu);
if ((er != EMULATE_DONE) && (er != EMULATE_AGAIN)) {
/* Couldn't emulate, trigger interrupt in guest */
kvmppc_trigger_fac_interrupt(vcpu, fac);
}
}
/* Enable facilities (TAR, EBB, DSCR) for the guest */
static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac)
{
bool guest_fac_enabled;
BUG_ON(!cpu_has_feature(CPU_FTR_ARCH_207S));
/*
* Not every facility is enabled by FSCR bits, check whether the
* guest has this facility enabled at all.
*/
switch (fac) {
case FSCR_TAR_LG:
case FSCR_EBB_LG:
guest_fac_enabled = (vcpu->arch.fscr & (1ULL << fac));
break;
case FSCR_TM_LG:
guest_fac_enabled = kvmppc_get_msr(vcpu) & MSR_TM;
break;
default:
guest_fac_enabled = false;
break;
}
if (!guest_fac_enabled) {
/* Facility not enabled by the guest */
kvmppc_trigger_fac_interrupt(vcpu, fac);
return RESUME_GUEST;
}
switch (fac) {
case FSCR_TAR_LG:
/* TAR switching isn't lazy in Linux yet */
current->thread.tar = mfspr(SPRN_TAR);
mtspr(SPRN_TAR, vcpu->arch.tar);
vcpu->arch.shadow_fscr |= FSCR_TAR;
break;
default:
kvmppc_emulate_fac(vcpu, fac);
break;
}
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
/* Since we disabled MSR_TM at privilege state, the mfspr instruction
* for TM spr can trigger TM fac unavailable. In this case, the
* emulation is handled by kvmppc_emulate_fac(), which invokes
* kvmppc_emulate_mfspr() finally. But note the mfspr can include
* RT for NV registers. So it need to restore those NV reg to reflect
* the update.
*/
if ((fac == FSCR_TM_LG) && !(kvmppc_get_msr(vcpu) & MSR_PR))
return RESUME_GUEST_NV;
#endif
return RESUME_GUEST;
}
void kvmppc_set_fscr(struct kvm_vcpu *vcpu, u64 fscr)
{
if ((vcpu->arch.fscr & FSCR_TAR) && !(fscr & FSCR_TAR)) {
/* TAR got dropped, drop it in shadow too */
kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
} else if (!(vcpu->arch.fscr & FSCR_TAR) && (fscr & FSCR_TAR)) {
vcpu->arch.fscr = fscr;
kvmppc_handle_fac(vcpu, FSCR_TAR_LG);
return;
}
vcpu->arch.fscr = fscr;
}
#endif
static void kvmppc_setup_debug(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
u64 msr = kvmppc_get_msr(vcpu);
kvmppc_set_msr(vcpu, msr | MSR_SE);
}
}
static void kvmppc_clear_debug(struct kvm_vcpu *vcpu)
{
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
u64 msr = kvmppc_get_msr(vcpu);
kvmppc_set_msr(vcpu, msr & ~MSR_SE);
}
}
static int kvmppc_exit_pr_progint(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
enum emulation_result er;
ulong flags;
u32 last_inst;
int emul, r;
/*
* shadow_srr1 only contains valid flags if we came here via a program
* exception. The other exceptions (emulation assist, FP unavailable,
* etc.) do not provide flags in SRR1, so use an illegal-instruction
* exception when injecting a program interrupt into the guest.
*/
if (exit_nr == BOOK3S_INTERRUPT_PROGRAM)
flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
else
flags = SRR1_PROGILL;
emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul != EMULATE_DONE)
return RESUME_GUEST;
if (kvmppc_get_msr(vcpu) & MSR_PR) {
#ifdef EXIT_DEBUG
pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
kvmppc_get_pc(vcpu), last_inst);
#endif
if ((last_inst & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) {
kvmppc_core_queue_program(vcpu, flags);
return RESUME_GUEST;
}
}
vcpu->stat.emulated_inst_exits++;
er = kvmppc_emulate_instruction(run, vcpu);
switch (er) {
case EMULATE_DONE:
r = RESUME_GUEST_NV;
break;
case EMULATE_AGAIN:
r = RESUME_GUEST;
break;
case EMULATE_FAIL:
pr_crit("%s: emulation at %lx failed (%08x)\n",
__func__, kvmppc_get_pc(vcpu), last_inst);
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
r = RESUME_HOST_NV;
break;
case EMULATE_EXIT_USER:
r = RESUME_HOST_NV;
break;
default:
BUG();
}
return r;
}
int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
int r = RESUME_HOST;
int s;
vcpu->stat.sum_exits++;
run->exit_reason = KVM_EXIT_UNKNOWN;
run->ready_for_interrupt_injection = 1;
/* We get here with MSR.EE=1 */
trace_kvm_exit(exit_nr, vcpu);
guest_exit();
switch (exit_nr) {
case BOOK3S_INTERRUPT_INST_STORAGE:
{
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
ulong shadow_srr1 = vcpu->arch.shadow_srr1;
vcpu->stat.pf_instruc++;
KVM: PPC: Book3S: Add hack for split real mode Today we handle split real mode by mapping both instruction and data faults into a special virtual address space that only exists during the split mode phase. This is good enough to catch 32bit Linux guests that use split real mode for copy_from/to_user. In this case we're always prefixed with 0xc0000000 for our instruction pointer and can map the user space process freely below there. However, that approach fails when we're running KVM inside of KVM. Here the 1st level last_inst reader may well be in the same virtual page as a 2nd level interrupt handler. It also fails when running Mac OS X guests. Here we have a 4G/4G split, so a kernel copy_from/to_user implementation can easily overlap with user space addresses. The architecturally correct way to fix this would be to implement an instruction interpreter in KVM that kicks in whenever we go into split real mode. This interpreter however would not receive a great amount of testing and be a lot of bloat for a reasonably isolated corner case. So I went back to the drawing board and tried to come up with a way to make split real mode work with a single flat address space. And then I realized that we could get away with the same trick that makes it work for Linux: Whenever we see an instruction address during split real mode that may collide, we just move it higher up the virtual address space to a place that hopefully does not collide (keep your fingers crossed!). That approach does work surprisingly well. I am able to successfully run Mac OS X guests with KVM and QEMU (no split real mode hacks like MOL) when I apply a tiny timing probe hack to QEMU. I'd say this is a win over even more broken split real mode :). Signed-off-by: Alexander Graf <agraf@suse.de>
2014-07-10 18:58:58 -06:00
if (kvmppc_is_split_real(vcpu))
kvmppc_fixup_split_real(vcpu);
#ifdef CONFIG_PPC_BOOK3S_32
/* We set segments as unused segments when invalidating them. So
* treat the respective fault as segment fault. */
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
{
struct kvmppc_book3s_shadow_vcpu *svcpu;
u32 sr;
svcpu = svcpu_get(vcpu);
sr = svcpu->sr[kvmppc_get_pc(vcpu) >> SID_SHIFT];
svcpu_put(svcpu);
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
if (sr == SR_INVALID) {
kvmppc_mmu_map_segment(vcpu, kvmppc_get_pc(vcpu));
r = RESUME_GUEST;
break;
}
}
#endif
/* only care about PTEG not found errors, but leave NX alone */
if (shadow_srr1 & 0x40000000) {
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
int idx = srcu_read_lock(&vcpu->kvm->srcu);
r = kvmppc_handle_pagefault(run, vcpu, kvmppc_get_pc(vcpu), exit_nr);
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
srcu_read_unlock(&vcpu->kvm->srcu, idx);
vcpu->stat.sp_instruc++;
} else if (vcpu->arch.mmu.is_dcbz32(vcpu) &&
(!(vcpu->arch.hflags & BOOK3S_HFLAG_DCBZ32))) {
/*
* XXX If we do the dcbz hack we use the NX bit to flush&patch the page,
* so we can't use the NX bit inside the guest. Let's cross our fingers,
* that no guest that needs the dcbz hack does NX.
*/
kvmppc_mmu_pte_flush(vcpu, kvmppc_get_pc(vcpu), ~0xFFFUL);
r = RESUME_GUEST;
} else {
kvmppc_core_queue_inst_storage(vcpu,
shadow_srr1 & 0x58000000);
r = RESUME_GUEST;
}
break;
}
case BOOK3S_INTERRUPT_DATA_STORAGE:
{
ulong dar = kvmppc_get_fault_dar(vcpu);
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
u32 fault_dsisr = vcpu->arch.fault_dsisr;
vcpu->stat.pf_storage++;
#ifdef CONFIG_PPC_BOOK3S_32
/* We set segments as unused segments when invalidating them. So
* treat the respective fault as segment fault. */
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
{
struct kvmppc_book3s_shadow_vcpu *svcpu;
u32 sr;
svcpu = svcpu_get(vcpu);
sr = svcpu->sr[dar >> SID_SHIFT];
svcpu_put(svcpu);
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
if (sr == SR_INVALID) {
kvmppc_mmu_map_segment(vcpu, dar);
r = RESUME_GUEST;
break;
}
}
#endif
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
/*
* We need to handle missing shadow PTEs, and
* protection faults due to us mapping a page read-only
* when the guest thinks it is writable.
*/
if (fault_dsisr & (DSISR_NOHPTE | DSISR_PROTFAULT)) {
int idx = srcu_read_lock(&vcpu->kvm->srcu);
r = kvmppc_handle_pagefault(run, vcpu, dar, exit_nr);
KVM: PPC: Book3S PR: Better handling of host-side read-only pages Currently we request write access to all pages that get mapped into the guest, even if the guest is only loading from the page. This reduces the effectiveness of KSM because it means that we unshare every page we access. Also, we always set the changed (C) bit in the guest HPTE if it allows writing, even for a guest load. This fixes both these problems. We pass an 'iswrite' flag to the mmu.xlate() functions and to kvmppc_mmu_map_page() to indicate whether the access is a load or a store. The mmu.xlate() functions now only set C for stores. kvmppc_gfn_to_pfn() now calls gfn_to_pfn_prot() instead of gfn_to_pfn() so that it can indicate whether we need write access to the page, and get back a 'writable' flag to indicate whether the page is writable or not. If that 'writable' flag is clear, we then make the host HPTE read-only even if the guest HPTE allowed writing. This means that we can get a protection fault when the guest writes to a page that it has mapped read-write but which is read-only on the host side (perhaps due to KSM having merged the page). Thus we now call kvmppc_handle_pagefault() for protection faults as well as HPTE not found faults. In kvmppc_handle_pagefault(), if the access was allowed by the guest HPTE and we thus need to install a new host HPTE, we then need to remove the old host HPTE if there is one. This is done with a new function, kvmppc_mmu_unmap_page(), which uses kvmppc_mmu_pte_vflush() to find and remove the old host HPTE. Since the memslot-related functions require the KVM SRCU read lock to be held, this adds srcu_read_lock/unlock pairs around the calls to kvmppc_handle_pagefault(). Finally, this changes kvmppc_mmu_book3s_32_xlate_pte() to not ignore guest HPTEs that don't permit access, and to return -EPERM for accesses that are not permitted by the page protections. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:51 -06:00
srcu_read_unlock(&vcpu->kvm->srcu, idx);
} else {
kvmppc_core_queue_data_storage(vcpu, dar, fault_dsisr);
r = RESUME_GUEST;
}
break;
}
case BOOK3S_INTERRUPT_DATA_SEGMENT:
if (kvmppc_mmu_map_segment(vcpu, kvmppc_get_fault_dar(vcpu)) < 0) {
kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu));
kvmppc_book3s_queue_irqprio(vcpu,
BOOK3S_INTERRUPT_DATA_SEGMENT);
}
r = RESUME_GUEST;
break;
case BOOK3S_INTERRUPT_INST_SEGMENT:
if (kvmppc_mmu_map_segment(vcpu, kvmppc_get_pc(vcpu)) < 0) {
kvmppc_book3s_queue_irqprio(vcpu,
BOOK3S_INTERRUPT_INST_SEGMENT);
}
r = RESUME_GUEST;
break;
/* We're good on these - the host merely wanted to get our attention */
case BOOK3S_INTERRUPT_DECREMENTER:
case BOOK3S_INTERRUPT_HV_DECREMENTER:
KVM: PPC: Book3S PR: Cope with doorbell interrupts When the PR host is running on a POWER8 machine in POWER8 mode, it will use doorbell interrupts for IPIs. If one of them arrives while we are in the guest, we pop out of the guest with trap number 0xA00, which isn't handled by kvmppc_handle_exit_pr, leading to the following BUG_ON: [ 331.436215] exit_nr=0xa00 | pc=0x1d2c | msr=0x800000000000d032 [ 331.437522] ------------[ cut here ]------------ [ 331.438296] kernel BUG at arch/powerpc/kvm/book3s_pr.c:982! [ 331.439063] Oops: Exception in kernel mode, sig: 5 [#2] [ 331.439819] SMP NR_CPUS=1024 NUMA pSeries [ 331.440552] Modules linked in: tun nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw virtio_net kvm binfmt_misc ibmvscsi scsi_transport_srp scsi_tgt virtio_blk [ 331.447614] CPU: 11 PID: 1296 Comm: qemu-system-ppc Tainted: G D 3.11.7-200.2.fc19.ppc64p7 #1 [ 331.448920] task: c0000003bdc8c000 ti: c0000003bd32c000 task.ti: c0000003bd32c000 [ 331.450088] NIP: d0000000025d6b9c LR: d0000000025d6b98 CTR: c0000000004cfdd0 [ 331.451042] REGS: c0000003bd32f420 TRAP: 0700 Tainted: G D (3.11.7-200.2.fc19.ppc64p7) [ 331.452331] MSR: 800000000282b032 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI> CR: 28004824 XER: 20000000 [ 331.454616] SOFTE: 1 [ 331.455106] CFAR: c000000000848bb8 [ 331.455726] GPR00: d0000000025d6b98 c0000003bd32f6a0 d0000000026017b8 0000000000000032 GPR04: c0000000018627f8 c000000001873208 320d0a3030303030 3030303030643033 GPR08: c000000000c490a8 0000000000000000 0000000000000000 0000000000000002 GPR12: 0000000028004822 c00000000fdc6300 0000000000000000 00000100076ec310 GPR16: 000000002ae343b8 00003ffffd397398 0000000000000000 0000000000000000 GPR20: 00000100076f16f4 00000100076ebe60 0000000000000008 ffffffffffffffff GPR24: 0000000000000000 0000008001041e60 0000000000000000 0000008001040ce8 GPR28: c0000003a2d80000 0000000000000a00 0000000000000001 c0000003a2681810 [ 331.466504] NIP [d0000000025d6b9c] .kvmppc_handle_exit_pr+0x75c/0xa80 [kvm] [ 331.466999] LR [d0000000025d6b98] .kvmppc_handle_exit_pr+0x758/0xa80 [kvm] [ 331.467517] Call Trace: [ 331.467909] [c0000003bd32f6a0] [d0000000025d6b98] .kvmppc_handle_exit_pr+0x758/0xa80 [kvm] (unreliable) [ 331.468553] [c0000003bd32f750] [d0000000025d98f0] kvm_start_lightweight+0xb4/0xc4 [kvm] [ 331.469189] [c0000003bd32f920] [d0000000025d7648] .kvmppc_vcpu_run_pr+0xd8/0x270 [kvm] [ 331.469838] [c0000003bd32f9c0] [d0000000025cf748] .kvmppc_vcpu_run+0xc8/0xf0 [kvm] [ 331.470790] [c0000003bd32fa50] [d0000000025cc19c] .kvm_arch_vcpu_ioctl_run+0x5c/0x1b0 [kvm] [ 331.471401] [c0000003bd32fae0] [d0000000025c4888] .kvm_vcpu_ioctl+0x478/0x730 [kvm] [ 331.472026] [c0000003bd32fc90] [c00000000026192c] .do_vfs_ioctl+0x4dc/0x7a0 [ 331.472561] [c0000003bd32fd80] [c000000000261cc4] .SyS_ioctl+0xd4/0xf0 [ 331.473095] [c0000003bd32fe30] [c000000000009ed8] syscall_exit+0x0/0x98 [ 331.473633] Instruction dump: [ 331.473766] 4bfff9b4 2b9d0800 419efc18 60000000 60420000 3d220000 e8bf11a0 e8df12a8 [ 331.474733] 7fa4eb78 e8698660 48015165 e8410028 <0fe00000> 813f00e4 3ba00000 39290001 [ 331.475386] ---[ end trace 49fc47d994c1f8f2 ]--- [ 331.479817] This fixes the problem by making kvmppc_handle_exit_pr() recognize the interrupt. We also need to jump to the doorbell interrupt handler in book3s_segment.S to handle the interrupt on the way out of the guest. Having done that, there's nothing further to be done in kvmppc_handle_exit_pr(). Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-01-08 03:25:36 -07:00
case BOOK3S_INTERRUPT_DOORBELL:
case BOOK3S_INTERRUPT_H_DOORBELL:
vcpu->stat.dec_exits++;
r = RESUME_GUEST;
break;
case BOOK3S_INTERRUPT_EXTERNAL:
case BOOK3S_INTERRUPT_EXTERNAL_HV:
case BOOK3S_INTERRUPT_H_VIRT:
vcpu->stat.ext_intr_exits++;
r = RESUME_GUEST;
break;
case BOOK3S_INTERRUPT_HMI:
case BOOK3S_INTERRUPT_PERFMON:
case BOOK3S_INTERRUPT_SYSTEM_RESET:
r = RESUME_GUEST;
break;
case BOOK3S_INTERRUPT_PROGRAM:
case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
r = kvmppc_exit_pr_progint(run, vcpu, exit_nr);
break;
case BOOK3S_INTERRUPT_SYSCALL:
{
u32 last_sc;
int emul;
/* Get last sc for papr */
if (vcpu->arch.papr_enabled) {
/* The sc instuction points SRR0 to the next inst */
emul = kvmppc_get_last_inst(vcpu, INST_SC, &last_sc);
if (emul != EMULATE_DONE) {
kvmppc_set_pc(vcpu, kvmppc_get_pc(vcpu) - 4);
r = RESUME_GUEST;
break;
}
}
if (vcpu->arch.papr_enabled &&
(last_sc == 0x44000022) &&
!(kvmppc_get_msr(vcpu) & MSR_PR)) {
/* SC 1 papr hypercalls */
ulong cmd = kvmppc_get_gpr(vcpu, 3);
int i;
#ifdef CONFIG_PPC_BOOK3S_64
if (kvmppc_h_pr(vcpu, cmd) == EMULATE_DONE) {
r = RESUME_GUEST;
break;
}
#endif
run->papr_hcall.nr = cmd;
for (i = 0; i < 9; ++i) {
ulong gpr = kvmppc_get_gpr(vcpu, 4 + i);
run->papr_hcall.args[i] = gpr;
}
run->exit_reason = KVM_EXIT_PAPR_HCALL;
vcpu->arch.hcall_needed = 1;
r = RESUME_HOST;
} else if (vcpu->arch.osi_enabled &&
(((u32)kvmppc_get_gpr(vcpu, 3)) == OSI_SC_MAGIC_R3) &&
(((u32)kvmppc_get_gpr(vcpu, 4)) == OSI_SC_MAGIC_R4)) {
/* MOL hypercalls */
u64 *gprs = run->osi.gprs;
int i;
run->exit_reason = KVM_EXIT_OSI;
for (i = 0; i < 32; i++)
gprs[i] = kvmppc_get_gpr(vcpu, i);
vcpu->arch.osi_needed = 1;
r = RESUME_HOST_NV;
} else if (!(kvmppc_get_msr(vcpu) & MSR_PR) &&
(((u32)kvmppc_get_gpr(vcpu, 0)) == KVM_SC_MAGIC_R0)) {
/* KVM PV hypercalls */
kvmppc_set_gpr(vcpu, 3, kvmppc_kvm_pv(vcpu));
r = RESUME_GUEST;
} else {
/* Guest syscalls */
vcpu->stat.syscall_exits++;
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
r = RESUME_GUEST;
}
break;
}
case BOOK3S_INTERRUPT_FP_UNAVAIL:
case BOOK3S_INTERRUPT_ALTIVEC:
case BOOK3S_INTERRUPT_VSX:
{
int ext_msr = 0;
int emul;
u32 last_inst;
if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE) {
/* Do paired single instruction emulation */
emul = kvmppc_get_last_inst(vcpu, INST_GENERIC,
&last_inst);
if (emul == EMULATE_DONE)
r = kvmppc_exit_pr_progint(run, vcpu, exit_nr);
else
r = RESUME_GUEST;
break;
}
/* Enable external provider */
switch (exit_nr) {
case BOOK3S_INTERRUPT_FP_UNAVAIL:
ext_msr = MSR_FP;
break;
case BOOK3S_INTERRUPT_ALTIVEC:
ext_msr = MSR_VEC;
break;
case BOOK3S_INTERRUPT_VSX:
ext_msr = MSR_VSX;
break;
}
r = kvmppc_handle_ext(vcpu, exit_nr, ext_msr);
break;
}
case BOOK3S_INTERRUPT_ALIGNMENT:
{
u32 last_inst;
int emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul == EMULATE_DONE) {
u32 dsisr;
u64 dar;
dsisr = kvmppc_alignment_dsisr(vcpu, last_inst);
dar = kvmppc_alignment_dar(vcpu, last_inst);
kvmppc_set_dsisr(vcpu, dsisr);
kvmppc_set_dar(vcpu, dar);
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
}
r = RESUME_GUEST;
break;
}
#ifdef CONFIG_PPC_BOOK3S_64
case BOOK3S_INTERRUPT_FAC_UNAVAIL:
r = kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56);
break;
#endif
case BOOK3S_INTERRUPT_MACHINE_CHECK:
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
r = RESUME_GUEST;
break;
case BOOK3S_INTERRUPT_TRACE:
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP) {
run->exit_reason = KVM_EXIT_DEBUG;
r = RESUME_HOST;
} else {
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
r = RESUME_GUEST;
}
break;
default:
{
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
ulong shadow_srr1 = vcpu->arch.shadow_srr1;
/* Ugh - bork here! What did we get? */
printk(KERN_EMERG "exit_nr=0x%x | pc=0x%lx | msr=0x%lx\n",
exit_nr, kvmppc_get_pc(vcpu), shadow_srr1);
r = RESUME_HOST;
BUG();
break;
}
}
if (!(r & RESUME_HOST)) {
/* To avoid clobbering exit_reason, only check for signals if
* we aren't already exiting to userspace for some other
* reason. */
/*
* Interrupts could be timers for the guest which we have to
* inject again, so let's postpone them until we're in the guest
* and if we really did time things so badly, then we just exit
* again due to a host external interrupt.
*/
s = kvmppc_prepare_to_enter(vcpu);
if (s <= 0)
r = s;
else {
/* interrupts now hard-disabled */
kvmppc_fix_ee_before_entry();
}
kvmppc_handle_lost_ext(vcpu);
}
trace_kvm_book3s_reenter(r, vcpu);
return r;
}
static int kvm_arch_vcpu_ioctl_get_sregs_pr(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
int i;
sregs->pvr = vcpu->arch.pvr;
sregs->u.s.sdr1 = to_book3s(vcpu)->sdr1;
if (vcpu->arch.hflags & BOOK3S_HFLAG_SLB) {
for (i = 0; i < 64; i++) {
sregs->u.s.ppc64.slb[i].slbe = vcpu->arch.slb[i].orige | i;
sregs->u.s.ppc64.slb[i].slbv = vcpu->arch.slb[i].origv;
}
} else {
for (i = 0; i < 16; i++)
sregs->u.s.ppc32.sr[i] = kvmppc_get_sr(vcpu, i);
for (i = 0; i < 8; i++) {
sregs->u.s.ppc32.ibat[i] = vcpu3s->ibat[i].raw;
sregs->u.s.ppc32.dbat[i] = vcpu3s->dbat[i].raw;
}
}
return 0;
}
static int kvm_arch_vcpu_ioctl_set_sregs_pr(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
struct kvmppc_vcpu_book3s *vcpu3s = to_book3s(vcpu);
int i;
kvmppc_set_pvr_pr(vcpu, sregs->pvr);
vcpu3s->sdr1 = sregs->u.s.sdr1;
#ifdef CONFIG_PPC_BOOK3S_64
if (vcpu->arch.hflags & BOOK3S_HFLAG_SLB) {
/* Flush all SLB entries */
vcpu->arch.mmu.slbmte(vcpu, 0, 0);
vcpu->arch.mmu.slbia(vcpu);
for (i = 0; i < 64; i++) {
u64 rb = sregs->u.s.ppc64.slb[i].slbe;
u64 rs = sregs->u.s.ppc64.slb[i].slbv;
if (rb & SLB_ESID_V)
vcpu->arch.mmu.slbmte(vcpu, rs, rb);
}
} else
#endif
{
for (i = 0; i < 16; i++) {
vcpu->arch.mmu.mtsrin(vcpu, i, sregs->u.s.ppc32.sr[i]);
}
for (i = 0; i < 8; i++) {
kvmppc_set_bat(vcpu, &(vcpu3s->ibat[i]), false,
(u32)sregs->u.s.ppc32.ibat[i]);
kvmppc_set_bat(vcpu, &(vcpu3s->ibat[i]), true,
(u32)(sregs->u.s.ppc32.ibat[i] >> 32));
kvmppc_set_bat(vcpu, &(vcpu3s->dbat[i]), false,
(u32)sregs->u.s.ppc32.dbat[i]);
kvmppc_set_bat(vcpu, &(vcpu3s->dbat[i]), true,
(u32)(sregs->u.s.ppc32.dbat[i] >> 32));
}
}
/* Flush the MMU after messing with the segments */
kvmppc_mmu_pte_flush(vcpu, 0, 0);
return 0;
}
static int kvmppc_get_one_reg_pr(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = 0;
switch (id) {
case KVM_REG_PPC_DEBUG_INST:
*val = get_reg_val(id, KVMPPC_INST_SW_BREAKPOINT);
break;
case KVM_REG_PPC_HIOR:
*val = get_reg_val(id, to_book3s(vcpu)->hior);
break;
case KVM_REG_PPC_VTB:
*val = get_reg_val(id, to_book3s(vcpu)->vtb);
break;
case KVM_REG_PPC_LPCR:
case KVM_REG_PPC_LPCR_64:
/*
* We are only interested in the LPCR_ILE bit
*/
if (vcpu->arch.intr_msr & MSR_LE)
*val = get_reg_val(id, LPCR_ILE);
else
*val = get_reg_val(id, 0);
break;
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
case KVM_REG_PPC_TFHAR:
*val = get_reg_val(id, vcpu->arch.tfhar);
break;
case KVM_REG_PPC_TFIAR:
*val = get_reg_val(id, vcpu->arch.tfiar);
break;
case KVM_REG_PPC_TEXASR:
*val = get_reg_val(id, vcpu->arch.texasr);
break;
case KVM_REG_PPC_TM_GPR0 ... KVM_REG_PPC_TM_GPR31:
*val = get_reg_val(id,
vcpu->arch.gpr_tm[id-KVM_REG_PPC_TM_GPR0]);
break;
case KVM_REG_PPC_TM_VSR0 ... KVM_REG_PPC_TM_VSR63:
{
int i, j;
i = id - KVM_REG_PPC_TM_VSR0;
if (i < 32)
for (j = 0; j < TS_FPRWIDTH; j++)
val->vsxval[j] = vcpu->arch.fp_tm.fpr[i][j];
else {
if (cpu_has_feature(CPU_FTR_ALTIVEC))
val->vval = vcpu->arch.vr_tm.vr[i-32];
else
r = -ENXIO;
}
break;
}
case KVM_REG_PPC_TM_CR:
*val = get_reg_val(id, vcpu->arch.cr_tm);
break;
case KVM_REG_PPC_TM_XER:
*val = get_reg_val(id, vcpu->arch.xer_tm);
break;
case KVM_REG_PPC_TM_LR:
*val = get_reg_val(id, vcpu->arch.lr_tm);
break;
case KVM_REG_PPC_TM_CTR:
*val = get_reg_val(id, vcpu->arch.ctr_tm);
break;
case KVM_REG_PPC_TM_FPSCR:
*val = get_reg_val(id, vcpu->arch.fp_tm.fpscr);
break;
case KVM_REG_PPC_TM_AMR:
*val = get_reg_val(id, vcpu->arch.amr_tm);
break;
case KVM_REG_PPC_TM_PPR:
*val = get_reg_val(id, vcpu->arch.ppr_tm);
break;
case KVM_REG_PPC_TM_VRSAVE:
*val = get_reg_val(id, vcpu->arch.vrsave_tm);
break;
case KVM_REG_PPC_TM_VSCR:
if (cpu_has_feature(CPU_FTR_ALTIVEC))
*val = get_reg_val(id, vcpu->arch.vr_tm.vscr.u[3]);
else
r = -ENXIO;
break;
case KVM_REG_PPC_TM_DSCR:
*val = get_reg_val(id, vcpu->arch.dscr_tm);
break;
case KVM_REG_PPC_TM_TAR:
*val = get_reg_val(id, vcpu->arch.tar_tm);
break;
#endif
default:
r = -EINVAL;
break;
}
return r;
}
static void kvmppc_set_lpcr_pr(struct kvm_vcpu *vcpu, u64 new_lpcr)
{
if (new_lpcr & LPCR_ILE)
vcpu->arch.intr_msr |= MSR_LE;
else
vcpu->arch.intr_msr &= ~MSR_LE;
}
static int kvmppc_set_one_reg_pr(struct kvm_vcpu *vcpu, u64 id,
union kvmppc_one_reg *val)
{
int r = 0;
switch (id) {
case KVM_REG_PPC_HIOR:
to_book3s(vcpu)->hior = set_reg_val(id, *val);
to_book3s(vcpu)->hior_explicit = true;
break;
case KVM_REG_PPC_VTB:
to_book3s(vcpu)->vtb = set_reg_val(id, *val);
break;
case KVM_REG_PPC_LPCR:
case KVM_REG_PPC_LPCR_64:
kvmppc_set_lpcr_pr(vcpu, set_reg_val(id, *val));
break;
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
case KVM_REG_PPC_TFHAR:
vcpu->arch.tfhar = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TFIAR:
vcpu->arch.tfiar = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TEXASR:
vcpu->arch.texasr = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_GPR0 ... KVM_REG_PPC_TM_GPR31:
vcpu->arch.gpr_tm[id - KVM_REG_PPC_TM_GPR0] =
set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_VSR0 ... KVM_REG_PPC_TM_VSR63:
{
int i, j;
i = id - KVM_REG_PPC_TM_VSR0;
if (i < 32)
for (j = 0; j < TS_FPRWIDTH; j++)
vcpu->arch.fp_tm.fpr[i][j] = val->vsxval[j];
else
if (cpu_has_feature(CPU_FTR_ALTIVEC))
vcpu->arch.vr_tm.vr[i-32] = val->vval;
else
r = -ENXIO;
break;
}
case KVM_REG_PPC_TM_CR:
vcpu->arch.cr_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_XER:
vcpu->arch.xer_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_LR:
vcpu->arch.lr_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_CTR:
vcpu->arch.ctr_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_FPSCR:
vcpu->arch.fp_tm.fpscr = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_AMR:
vcpu->arch.amr_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_PPR:
vcpu->arch.ppr_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_VRSAVE:
vcpu->arch.vrsave_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_VSCR:
if (cpu_has_feature(CPU_FTR_ALTIVEC))
vcpu->arch.vr.vscr.u[3] = set_reg_val(id, *val);
else
r = -ENXIO;
break;
case KVM_REG_PPC_TM_DSCR:
vcpu->arch.dscr_tm = set_reg_val(id, *val);
break;
case KVM_REG_PPC_TM_TAR:
vcpu->arch.tar_tm = set_reg_val(id, *val);
break;
#endif
default:
r = -EINVAL;
break;
}
return r;
}
static struct kvm_vcpu *kvmppc_core_vcpu_create_pr(struct kvm *kvm,
unsigned int id)
{
struct kvmppc_vcpu_book3s *vcpu_book3s;
struct kvm_vcpu *vcpu;
int err = -ENOMEM;
unsigned long p;
vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
if (!vcpu)
goto out;
vcpu_book3s = vzalloc(sizeof(struct kvmppc_vcpu_book3s));
if (!vcpu_book3s)
goto free_vcpu;
vcpu->arch.book3s = vcpu_book3s;
#ifdef CONFIG_KVM_BOOK3S_32_HANDLER
vcpu->arch.shadow_vcpu =
kzalloc(sizeof(*vcpu->arch.shadow_vcpu), GFP_KERNEL);
if (!vcpu->arch.shadow_vcpu)
goto free_vcpu3s;
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
#endif
err = kvm_vcpu_init(vcpu, kvm, id);
if (err)
goto free_shadow_vcpu;
err = -ENOMEM;
p = __get_free_page(GFP_KERNEL|__GFP_ZERO);
if (!p)
goto uninit_vcpu;
vcpu->arch.shared = (void *)p;
#ifdef CONFIG_PPC_BOOK3S_64
/* Always start the shared struct in native endian mode */
#ifdef __BIG_ENDIAN__
vcpu->arch.shared_big_endian = true;
#else
vcpu->arch.shared_big_endian = false;
#endif
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
/*
* Default to the same as the host if we're on sufficiently
* recent machine that we have 1TB segments;
* otherwise default to PPC970FX.
*/
vcpu->arch.pvr = 0x3C0301;
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
vcpu->arch.pvr = mfspr(SPRN_PVR);
vcpu->arch.intr_msr = MSR_SF;
#else
/* default to book3s_32 (750) */
vcpu->arch.pvr = 0x84202;
#endif
kvmppc_set_pvr_pr(vcpu, vcpu->arch.pvr);
vcpu->arch.slb_nr = 64;
vcpu->arch.shadow_msr = MSR_USER64 & ~MSR_LE;
err = kvmppc_mmu_init(vcpu);
if (err < 0)
goto uninit_vcpu;
return vcpu;
uninit_vcpu:
kvm_vcpu_uninit(vcpu);
free_shadow_vcpu:
#ifdef CONFIG_KVM_BOOK3S_32_HANDLER
kfree(vcpu->arch.shadow_vcpu);
free_vcpu3s:
KVM: PPC: Book3S PR: Keep volatile reg values in vcpu rather than shadow_vcpu Currently PR-style KVM keeps the volatile guest register values (R0 - R13, CR, LR, CTR, XER, PC) in a shadow_vcpu struct rather than the main kvm_vcpu struct. For 64-bit, the shadow_vcpu exists in two places, a kmalloc'd struct and in the PACA, and it gets copied back and forth in kvmppc_core_vcpu_load/put(), because the real-mode code can't rely on being able to access the kmalloc'd struct. This changes the code to copy the volatile values into the shadow_vcpu as one of the last things done before entering the guest. Similarly the values are copied back out of the shadow_vcpu to the kvm_vcpu immediately after exiting the guest. We arrange for interrupts to be still disabled at this point so that we can't get preempted on 64-bit and end up copying values from the wrong PACA. This means that the accessor functions in kvm_book3s.h for these registers are greatly simplified, and are same between PR and HV KVM. In places where accesses to shadow_vcpu fields are now replaced by accesses to the kvm_vcpu, we can also remove the svcpu_get/put pairs. Finally, on 64-bit, we don't need the kmalloc'd struct at all any more. With this, the time to read the PVR one million times in a loop went from 567.7ms to 575.5ms (averages of 6 values), an increase of about 1.4% for this worse-case test for guest entries and exits. The standard deviation of the measurements is about 11ms, so the difference is only marginally significant statistically. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:43 -06:00
#endif
vfree(vcpu_book3s);
free_vcpu:
kmem_cache_free(kvm_vcpu_cache, vcpu);
out:
return ERR_PTR(err);
}
static void kvmppc_core_vcpu_free_pr(struct kvm_vcpu *vcpu)
{
struct kvmppc_vcpu_book3s *vcpu_book3s = to_book3s(vcpu);
free_page((unsigned long)vcpu->arch.shared & PAGE_MASK);
kvm_vcpu_uninit(vcpu);
#ifdef CONFIG_KVM_BOOK3S_32_HANDLER
kfree(vcpu->arch.shadow_vcpu);
#endif
vfree(vcpu_book3s);
kmem_cache_free(kvm_vcpu_cache, vcpu);
}
static int kvmppc_vcpu_run_pr(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
{
int ret;
#ifdef CONFIG_ALTIVEC
unsigned long uninitialized_var(vrsave);
#endif
/* Check if we can run the vcpu at all */
if (!vcpu->arch.sane) {
kvm_run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
ret = -EINVAL;
goto out;
}
kvmppc_setup_debug(vcpu);
/*
* Interrupts could be timers for the guest which we have to inject
* again, so let's postpone them until we're in the guest and if we
* really did time things so badly, then we just exit again due to
* a host external interrupt.
*/
ret = kvmppc_prepare_to_enter(vcpu);
if (ret <= 0)
goto out;
/* interrupts now hard-disabled */
/* Save FPU, Altivec and VSX state */
giveup_all(current);
/* Preload FPU if it's enabled */
if (kvmppc_get_msr(vcpu) & MSR_FP)
kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);
kvmppc_fix_ee_before_entry();
ret = __kvmppc_vcpu_run(kvm_run, vcpu);
kvmppc_clear_debug(vcpu);
/* No need for guest_exit. It's done in handle_exit.
We also get here with interrupts enabled. */
/* Make sure we save the guest FPU/Altivec/VSX state */
KVM: PPC: Book3S PR: Fix VSX handling This fixes various issues in how we were handling the VSX registers that exist on POWER7 machines. First, we were running off the end of the current->thread.fpr[] array. Ultimately this was because the vcpu->arch.vsr[] array is sized to be able to store both the FP registers and the extra VSX registers (i.e. 64 entries), but PR KVM only uses it for the extra VSX registers (i.e. 32 entries). Secondly, calling load_up_vsx() from C code is a really bad idea, because it jumps to fast_exception_return at the end, rather than returning with a blr instruction. This was causing it to jump off to a random location with random register contents, since it was using the largely uninitialized stack frame created by kvmppc_load_up_vsx. In fact, it isn't necessary to call either __giveup_vsx or load_up_vsx, since giveup_fpu and load_up_fpu handle the extra VSX registers as well as the standard FP registers on machines with VSX. Also, since VSX instructions can access the VMX registers and the FP registers as well as the extra VSX registers, we have to load up the FP and VMX registers before we can turn on the MSR_VSX bit for the guest. Conversely, if we save away any of the VSX or FP registers, we have to turn off MSR_VSX for the guest. To handle all this, it is more convenient for a single call to kvmppc_giveup_ext() to handle all the state saving that needs to be done, so we make it take a set of MSR bits rather than just one, and the switch statement becomes a series of if statements. Similarly kvmppc_handle_ext needs to be able to load up more than one set of registers. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2012-11-04 11:16:46 -07:00
kvmppc_giveup_ext(vcpu, MSR_FP | MSR_VEC | MSR_VSX);
/* Make sure we save the guest TAR/EBB/DSCR state */
kvmppc_giveup_fac(vcpu, FSCR_TAR_LG);
out:
vcpu->mode = OUTSIDE_GUEST_MODE;
return ret;
}
/*
* Get (and clear) the dirty memory log for a memory slot.
*/
static int kvm_vm_ioctl_get_dirty_log_pr(struct kvm *kvm,
struct kvm_dirty_log *log)
{
struct kvm_memslots *slots;
struct kvm_memory_slot *memslot;
struct kvm_vcpu *vcpu;
ulong ga, ga_end;
int is_dirty = 0;
int r;
unsigned long n;
mutex_lock(&kvm->slots_lock);
r = kvm_get_dirty_log(kvm, log, &is_dirty);
if (r)
goto out;
/* If nothing is dirty, don't bother messing with page tables. */
if (is_dirty) {
slots = kvm_memslots(kvm);
memslot = id_to_memslot(slots, log->slot);
ga = memslot->base_gfn << PAGE_SHIFT;
ga_end = ga + (memslot->npages << PAGE_SHIFT);
kvm_for_each_vcpu(n, vcpu, kvm)
kvmppc_mmu_pte_pflush(vcpu, ga, ga_end);
n = kvm_dirty_bitmap_bytes(memslot);
memset(memslot->dirty_bitmap, 0, n);
}
r = 0;
out:
mutex_unlock(&kvm->slots_lock);
return r;
}
static void kvmppc_core_flush_memslot_pr(struct kvm *kvm,
struct kvm_memory_slot *memslot)
{
return;
}
static int kvmppc_core_prepare_memory_region_pr(struct kvm *kvm,
struct kvm_memory_slot *memslot,
const struct kvm_userspace_memory_region *mem)
{
return 0;
}
static void kvmppc_core_commit_memory_region_pr(struct kvm *kvm,
const struct kvm_userspace_memory_region *mem,
const struct kvm_memory_slot *old,
const struct kvm_memory_slot *new)
{
return;
}
static void kvmppc_core_free_memslot_pr(struct kvm_memory_slot *free,
struct kvm_memory_slot *dont)
{
return;
}
static int kvmppc_core_create_memslot_pr(struct kvm_memory_slot *slot,
unsigned long npages)
{
return 0;
}
#ifdef CONFIG_PPC64
static int kvm_vm_ioctl_get_smmu_info_pr(struct kvm *kvm,
struct kvm_ppc_smmu_info *info)
{
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
long int i;
struct kvm_vcpu *vcpu;
info->flags = 0;
/* SLB is always 64 entries */
info->slb_size = 64;
/* Standard 4k base page size segment */
info->sps[0].page_shift = 12;
info->sps[0].slb_enc = 0;
info->sps[0].enc[0].page_shift = 12;
info->sps[0].enc[0].pte_enc = 0;
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
/*
* 64k large page size.
* We only want to put this in if the CPUs we're emulating
* support it, but unfortunately we don't have a vcpu easily
* to hand here to test. Just pick the first vcpu, and if
* that doesn't exist yet, report the minimum capability,
* i.e., no 64k pages.
* 1T segment support goes along with 64k pages.
*/
i = 1;
vcpu = kvm_get_vcpu(kvm, 0);
if (vcpu && (vcpu->arch.hflags & BOOK3S_HFLAG_MULTI_PGSIZE)) {
info->flags = KVM_PPC_1T_SEGMENTS;
info->sps[i].page_shift = 16;
info->sps[i].slb_enc = SLB_VSID_L | SLB_VSID_LP_01;
info->sps[i].enc[0].page_shift = 16;
info->sps[i].enc[0].pte_enc = 1;
++i;
}
/* Standard 16M large page size segment */
KVM: PPC: Book3S PR: Allow guest to use 64k pages This adds the code to interpret 64k HPTEs in the guest hashed page table (HPT), 64k SLB entries, and to tell the guest about 64k pages in kvm_vm_ioctl_get_smmu_info(). Guest 64k pages are still shadowed by 4k pages. This also adds another hash table to the four we have already in book3s_mmu_hpte.c to allow us to find all the PTEs that we have instantiated that match a given 64k guest page. The tlbie instruction changed starting with POWER6 to use a bit in the RB operand to indicate large page invalidations, and to use other RB bits to indicate the base and actual page sizes and the segment size. 64k pages came in slightly earlier, with POWER5++. We use one bit in vcpu->arch.hflags to indicate that the emulated cpu supports 64k pages, and another to indicate that it has the new tlbie definition. The KVM_PPC_GET_SMMU_INFO ioctl presents a bit of a problem, because the MMU capabilities depend on which CPU model we're emulating, but it is a VM ioctl not a VCPU ioctl and therefore doesn't get passed a VCPU fd. In addition, commonly-used userspace (QEMU) calls it before setting the PVR for any VCPU. Therefore, as a best effort we look at the first vcpu in the VM and return 64k pages or not depending on its capabilities. We also make the PVR default to the host PVR on recent CPUs that support 1TB segments (and therefore multiple page sizes as well) so that KVM_PPC_GET_SMMU_INFO will include 64k page and 1TB segment support on those CPUs. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2013-09-19 22:52:44 -06:00
info->sps[i].page_shift = 24;
info->sps[i].slb_enc = SLB_VSID_L;
info->sps[i].enc[0].page_shift = 24;
info->sps[i].enc[0].pte_enc = 0;
return 0;
}
static int kvm_configure_mmu_pr(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg)
{
if (!cpu_has_feature(CPU_FTR_ARCH_300))
return -ENODEV;
/* Require flags and process table base and size to all be zero. */
if (cfg->flags || cfg->process_table)
return -EINVAL;
return 0;
}
#else
static int kvm_vm_ioctl_get_smmu_info_pr(struct kvm *kvm,
struct kvm_ppc_smmu_info *info)
{
/* We should not get called */
BUG();
}
#endif /* CONFIG_PPC64 */
static unsigned int kvm_global_user_count = 0;
static DEFINE_SPINLOCK(kvm_global_user_count_lock);
static int kvmppc_core_init_vm_pr(struct kvm *kvm)
{
mutex_init(&kvm->arch.hpt_mutex);
KVM: PPC: Book3S: Controls for in-kernel sPAPR hypercall handling This provides a way for userspace controls which sPAPR hcalls get handled in the kernel. Each hcall can be individually enabled or disabled for in-kernel handling, except for H_RTAS. The exception for H_RTAS is because userspace can already control whether individual RTAS functions are handled in-kernel or not via the KVM_PPC_RTAS_DEFINE_TOKEN ioctl, and because the numeric value for H_RTAS is out of the normal sequence of hcall numbers. Hcalls are enabled or disabled using the KVM_ENABLE_CAP ioctl for the KVM_CAP_PPC_ENABLE_HCALL capability on the file descriptor for the VM. The args field of the struct kvm_enable_cap specifies the hcall number in args[0] and the enable/disable flag in args[1]; 0 means disable in-kernel handling (so that the hcall will always cause an exit to userspace) and 1 means enable. Enabling or disabling in-kernel handling of an hcall is effective across the whole VM. The ability for KVM_ENABLE_CAP to be used on a VM file descriptor on PowerPC is new, added by this commit. The KVM_CAP_ENABLE_CAP_VM capability advertises that this ability exists. When a VM is created, an initial set of hcalls are enabled for in-kernel handling. The set that is enabled is the set that have an in-kernel implementation at this point. Any new hcall implementations from this point onwards should not be added to the default set without a good reason. No distinction is made between real-mode and virtual-mode hcall implementations; the one setting controls them both. Signed-off-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Alexander Graf <agraf@suse.de>
2014-06-01 19:02:59 -06:00
#ifdef CONFIG_PPC_BOOK3S_64
/* Start out with the default set of hcalls enabled */
kvmppc_pr_init_default_hcalls(kvm);
#endif
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
spin_lock(&kvm_global_user_count_lock);
if (++kvm_global_user_count == 1)
pseries_disable_reloc_on_exc();
spin_unlock(&kvm_global_user_count_lock);
}
return 0;
}
static void kvmppc_core_destroy_vm_pr(struct kvm *kvm)
{
#ifdef CONFIG_PPC64
WARN_ON(!list_empty(&kvm->arch.spapr_tce_tables));
#endif
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
spin_lock(&kvm_global_user_count_lock);
BUG_ON(kvm_global_user_count == 0);
if (--kvm_global_user_count == 0)
pseries_enable_reloc_on_exc();
spin_unlock(&kvm_global_user_count_lock);
}
}
static int kvmppc_core_check_processor_compat_pr(void)
{
/*
* PR KVM can work on POWER9 inside a guest partition
* running in HPT mode. It can't work if we are using
* radix translation (because radix provides no way for
* a process to have unique translations in quadrant 3).
*/
if (cpu_has_feature(CPU_FTR_ARCH_300) && radix_enabled())
return -EIO;
return 0;
}
static long kvm_arch_vm_ioctl_pr(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
return -ENOTTY;
}
static struct kvmppc_ops kvm_ops_pr = {
.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_pr,
.set_sregs = kvm_arch_vcpu_ioctl_set_sregs_pr,
.get_one_reg = kvmppc_get_one_reg_pr,
.set_one_reg = kvmppc_set_one_reg_pr,
.vcpu_load = kvmppc_core_vcpu_load_pr,
.vcpu_put = kvmppc_core_vcpu_put_pr,
.set_msr = kvmppc_set_msr_pr,
.vcpu_run = kvmppc_vcpu_run_pr,
.vcpu_create = kvmppc_core_vcpu_create_pr,
.vcpu_free = kvmppc_core_vcpu_free_pr,
.check_requests = kvmppc_core_check_requests_pr,
.get_dirty_log = kvm_vm_ioctl_get_dirty_log_pr,
.flush_memslot = kvmppc_core_flush_memslot_pr,
.prepare_memory_region = kvmppc_core_prepare_memory_region_pr,
.commit_memory_region = kvmppc_core_commit_memory_region_pr,
.unmap_hva_range = kvm_unmap_hva_range_pr,
.age_hva = kvm_age_hva_pr,
.test_age_hva = kvm_test_age_hva_pr,
.set_spte_hva = kvm_set_spte_hva_pr,
.mmu_destroy = kvmppc_mmu_destroy_pr,
.free_memslot = kvmppc_core_free_memslot_pr,
.create_memslot = kvmppc_core_create_memslot_pr,
.init_vm = kvmppc_core_init_vm_pr,
.destroy_vm = kvmppc_core_destroy_vm_pr,
.get_smmu_info = kvm_vm_ioctl_get_smmu_info_pr,
.emulate_op = kvmppc_core_emulate_op_pr,
.emulate_mtspr = kvmppc_core_emulate_mtspr_pr,
.emulate_mfspr = kvmppc_core_emulate_mfspr_pr,
.fast_vcpu_kick = kvm_vcpu_kick,
.arch_vm_ioctl = kvm_arch_vm_ioctl_pr,
#ifdef CONFIG_PPC_BOOK3S_64
.hcall_implemented = kvmppc_hcall_impl_pr,
.configure_mmu = kvm_configure_mmu_pr,
#endif
.giveup_ext = kvmppc_giveup_ext,
};
int kvmppc_book3s_init_pr(void)
{
int r;
r = kvmppc_core_check_processor_compat_pr();
if (r < 0)
return r;
kvm_ops_pr.owner = THIS_MODULE;
kvmppc_pr_ops = &kvm_ops_pr;
r = kvmppc_mmu_hpte_sysinit();
return r;
}
void kvmppc_book3s_exit_pr(void)
{
kvmppc_pr_ops = NULL;
kvmppc_mmu_hpte_sysexit();
}
/*
* We only support separate modules for book3s 64
*/
#ifdef CONFIG_PPC_BOOK3S_64
module_init(kvmppc_book3s_init_pr);
module_exit(kvmppc_book3s_exit_pr);
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(KVM_MINOR);
MODULE_ALIAS("devname:kvm");
#endif