KVM: PPC: Convert MSR to shared page
One of the most obvious registers to share with the guest directly is the
MSR. The MSR contains the "interrupts enabled" flag which the guest has to
toggle in critical sections.
So in order to bring the overhead of interrupt en- and disabling down, let's
put msr into the shared page. Keep in mind that even though you can fully read
its contents, writing to it doesn't always update all state. There are a few
safe fields that don't require hypervisor interaction. See the documentation
for a list of MSR bits that are safe to be set from inside the guest.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index b3385dd..2efe6924 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -115,31 +115,31 @@
static void kvmppc_recalc_shadow_msr(struct kvm_vcpu *vcpu)
{
- vcpu->arch.shadow_msr = vcpu->arch.msr;
+ ulong smsr = vcpu->arch.shared->msr;
+
/* Guest MSR values */
- vcpu->arch.shadow_msr &= MSR_FE0 | MSR_FE1 | MSR_SF | MSR_SE |
- MSR_BE | MSR_DE;
+ smsr &= MSR_FE0 | MSR_FE1 | MSR_SF | MSR_SE | MSR_BE | MSR_DE;
/* Process MSR values */
- vcpu->arch.shadow_msr |= MSR_ME | MSR_RI | MSR_IR | MSR_DR | MSR_PR |
- MSR_EE;
+ smsr |= MSR_ME | MSR_RI | MSR_IR | MSR_DR | MSR_PR | MSR_EE;
/* External providers the guest reserved */
- vcpu->arch.shadow_msr |= (vcpu->arch.msr & vcpu->arch.guest_owned_ext);
+ smsr |= (vcpu->arch.shared->msr & vcpu->arch.guest_owned_ext);
/* 64-bit Process MSR values */
#ifdef CONFIG_PPC_BOOK3S_64
- vcpu->arch.shadow_msr |= MSR_ISF | MSR_HV;
+ smsr |= MSR_ISF | MSR_HV;
#endif
+ vcpu->arch.shadow_msr = smsr;
}
void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
{
- ulong old_msr = vcpu->arch.msr;
+ ulong old_msr = vcpu->arch.shared->msr;
#ifdef EXIT_DEBUG
printk(KERN_INFO "KVM: Set MSR to 0x%llx\n", msr);
#endif
msr &= to_book3s(vcpu)->msr_mask;
- vcpu->arch.msr = msr;
+ vcpu->arch.shared->msr = msr;
kvmppc_recalc_shadow_msr(vcpu);
if (msr & (MSR_WE|MSR_POW)) {
@@ -149,21 +149,21 @@
}
}
- if ((vcpu->arch.msr & (MSR_PR|MSR_IR|MSR_DR)) !=
+ if ((vcpu->arch.shared->msr & (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 FPU if it's enabled */
- if (vcpu->arch.msr & MSR_FP)
+ if (vcpu->arch.shared->msr & MSR_FP)
kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);
}
void kvmppc_inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 flags)
{
vcpu->arch.srr0 = kvmppc_get_pc(vcpu);
- vcpu->arch.srr1 = vcpu->arch.msr | flags;
+ vcpu->arch.srr1 = vcpu->arch.shared->msr | flags;
kvmppc_set_pc(vcpu, to_book3s(vcpu)->hior + vec);
vcpu->arch.mmu.reset_msr(vcpu);
}
@@ -254,11 +254,11 @@
switch (priority) {
case BOOK3S_IRQPRIO_DECREMENTER:
- deliver = vcpu->arch.msr & MSR_EE;
+ deliver = vcpu->arch.shared->msr & MSR_EE;
vec = BOOK3S_INTERRUPT_DECREMENTER;
break;
case BOOK3S_IRQPRIO_EXTERNAL:
- deliver = vcpu->arch.msr & MSR_EE;
+ deliver = vcpu->arch.shared->msr & MSR_EE;
vec = BOOK3S_INTERRUPT_EXTERNAL;
break;
case BOOK3S_IRQPRIO_SYSTEM_RESET:
@@ -437,7 +437,7 @@
static int kvmppc_xlate(struct kvm_vcpu *vcpu, ulong eaddr, bool data,
struct kvmppc_pte *pte)
{
- int relocated = (vcpu->arch.msr & (data ? MSR_DR : MSR_IR));
+ int relocated = (vcpu->arch.shared->msr & (data ? MSR_DR : MSR_IR));
int r;
if (relocated) {
@@ -545,8 +545,8 @@
int page_found = 0;
struct kvmppc_pte pte;
bool is_mmio = false;
- bool dr = (vcpu->arch.msr & MSR_DR) ? true : false;
- bool ir = (vcpu->arch.msr & MSR_IR) ? true : false;
+ bool dr = (vcpu->arch.shared->msr & MSR_DR) ? true : false;
+ bool ir = (vcpu->arch.shared->msr & MSR_IR) ? true : false;
u64 vsid;
relocated = data ? dr : ir;
@@ -563,7 +563,7 @@
pte.vpage = eaddr >> 12;
}
- switch (vcpu->arch.msr & (MSR_DR|MSR_IR)) {
+ switch (vcpu->arch.shared->msr & (MSR_DR|MSR_IR)) {
case 0:
pte.vpage |= ((u64)VSID_REAL << (SID_SHIFT - 12));
break;
@@ -571,7 +571,7 @@
case MSR_IR:
vcpu->arch.mmu.esid_to_vsid(vcpu, eaddr >> SID_SHIFT, &vsid);
- if ((vcpu->arch.msr & (MSR_DR|MSR_IR)) == MSR_DR)
+ if ((vcpu->arch.shared->msr & (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));
@@ -596,14 +596,16 @@
/* Page not found in guest PTE entries */
vcpu->arch.dear = kvmppc_get_fault_dar(vcpu);
to_book3s(vcpu)->dsisr = to_svcpu(vcpu)->fault_dsisr;
- vcpu->arch.msr |= (to_svcpu(vcpu)->shadow_srr1 & 0x00000000f8000000ULL);
+ vcpu->arch.shared->msr |=
+ (to_svcpu(vcpu)->shadow_srr1 & 0x00000000f8000000ULL);
kvmppc_book3s_queue_irqprio(vcpu, vec);
} else if (page_found == -EPERM) {
/* Storage protection */
vcpu->arch.dear = kvmppc_get_fault_dar(vcpu);
to_book3s(vcpu)->dsisr = to_svcpu(vcpu)->fault_dsisr & ~DSISR_NOHPTE;
to_book3s(vcpu)->dsisr |= DSISR_PROTFAULT;
- vcpu->arch.msr |= (to_svcpu(vcpu)->shadow_srr1 & 0x00000000f8000000ULL);
+ vcpu->arch.shared->msr |=
+ (to_svcpu(vcpu)->shadow_srr1 & 0x00000000f8000000ULL);
kvmppc_book3s_queue_irqprio(vcpu, vec);
} else if (page_found == -EINVAL) {
/* Page not found in guest SLB */
@@ -695,9 +697,11 @@
ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false);
if (ret == -ENOENT) {
- vcpu->arch.msr = kvmppc_set_field(vcpu->arch.msr, 33, 33, 1);
- vcpu->arch.msr = kvmppc_set_field(vcpu->arch.msr, 34, 36, 0);
- vcpu->arch.msr = kvmppc_set_field(vcpu->arch.msr, 42, 47, 0);
+ ulong msr = vcpu->arch.shared->msr;
+
+ msr = kvmppc_set_field(msr, 33, 33, 1);
+ msr = kvmppc_set_field(msr, 34, 36, 0);
+ vcpu->arch.shared->msr = kvmppc_set_field(msr, 42, 47, 0);
kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE);
return EMULATE_AGAIN;
}
@@ -736,7 +740,7 @@
if (vcpu->arch.hflags & BOOK3S_HFLAG_PAIRED_SINGLE)
return RESUME_GUEST;
- if (!(vcpu->arch.msr & msr)) {
+ if (!(vcpu->arch.shared->msr & msr)) {
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
return RESUME_GUEST;
}
@@ -804,7 +808,7 @@
if ((exit_nr != 0x900) && (exit_nr != 0x500))
printk(KERN_EMERG "exit_nr=0x%x | pc=0x%lx | dar=0x%lx | msr=0x%lx\n",
exit_nr, kvmppc_get_pc(vcpu), kvmppc_get_fault_dar(vcpu),
- vcpu->arch.msr);
+ vcpu->arch.shared->msr);
#endif
kvm_resched(vcpu);
switch (exit_nr) {
@@ -836,7 +840,8 @@
kvmppc_mmu_pte_flush(vcpu, kvmppc_get_pc(vcpu), ~0xFFFUL);
r = RESUME_GUEST;
} else {
- vcpu->arch.msr |= to_svcpu(vcpu)->shadow_srr1 & 0x58000000;
+ vcpu->arch.shared->msr |=
+ to_svcpu(vcpu)->shadow_srr1 & 0x58000000;
kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
kvmppc_mmu_pte_flush(vcpu, kvmppc_get_pc(vcpu), ~0xFFFUL);
r = RESUME_GUEST;
@@ -904,7 +909,7 @@
program_interrupt:
flags = to_svcpu(vcpu)->shadow_srr1 & 0x1f0000ull;
- if (vcpu->arch.msr & MSR_PR) {
+ if (vcpu->arch.shared->msr & MSR_PR) {
#ifdef EXIT_DEBUG
printk(KERN_INFO "Userspace triggered 0x700 exception at 0x%lx (0x%x)\n", kvmppc_get_pc(vcpu), kvmppc_get_last_inst(vcpu));
#endif
@@ -1052,7 +1057,7 @@
regs->ctr = kvmppc_get_ctr(vcpu);
regs->lr = kvmppc_get_lr(vcpu);
regs->xer = kvmppc_get_xer(vcpu);
- regs->msr = vcpu->arch.msr;
+ regs->msr = vcpu->arch.shared->msr;
regs->srr0 = vcpu->arch.srr0;
regs->srr1 = vcpu->arch.srr1;
regs->pid = vcpu->arch.pid;
@@ -1353,7 +1358,7 @@
local_irq_enable();
/* Preload FPU if it's enabled */
- if (vcpu->arch.msr & MSR_FP)
+ if (vcpu->arch.shared->msr & MSR_FP)
kvmppc_handle_ext(vcpu, BOOK3S_INTERRUPT_FP_UNAVAIL, MSR_FP);
ret = __kvmppc_vcpu_entry(kvm_run, vcpu);
