* [PATCH 1/2] KVM: Replace reads of vcpu->arch.cr3 by an accessor
2010-12-05 17:01 [PATCH 0/2] Keep cr3 cached in VMCS Avi Kivity
@ 2010-12-05 17:01 ` Avi Kivity
2010-12-05 17:01 ` [PATCH 2/2] KVM: Fetch guest cr3 from hardware on demand Avi Kivity
1 sibling, 0 replies; 4+ messages in thread
From: Avi Kivity @ 2010-12-05 17:01 UTC (permalink / raw)
To: Marcelo Tosatti, kvm
This allows us to keep cr3 in the VMCS, later on.
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/kvm_cache_regs.h | 5 +++++
arch/x86/kvm/mmu.c | 6 +++---
arch/x86/kvm/svm.c | 8 ++++----
arch/x86/kvm/vmx.c | 7 ++++---
arch/x86/kvm/x86.c | 19 ++++++++++---------
5 files changed, 26 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 95ac3af..a6bf8db 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -73,6 +73,11 @@ static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
return vcpu->arch.cr4 & mask;
}
+static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.cr3;
+}
+
static inline ulong kvm_read_cr4(struct kvm_vcpu *vcpu)
{
return kvm_read_cr4_bits(vcpu, ~0UL);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 04c49b9..e0c447f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2726,13 +2726,13 @@ void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu)
static void paging_new_cr3(struct kvm_vcpu *vcpu)
{
- pgprintk("%s: cr3 %lx\n", __func__, vcpu->arch.cr3);
+ pgprintk("%s: cr3 %lx\n", __func__, kvm_read_cr3(vcpu));
mmu_free_roots(vcpu);
}
static unsigned long get_cr3(struct kvm_vcpu *vcpu)
{
- return vcpu->arch.cr3;
+ return kvm_read_cr3(vcpu);
}
static void inject_page_fault(struct kvm_vcpu *vcpu,
@@ -3631,7 +3631,7 @@ static int kvm_pv_mmu_write(struct kvm_vcpu *vcpu,
static int kvm_pv_mmu_flush_tlb(struct kvm_vcpu *vcpu)
{
- (void)kvm_set_cr3(vcpu, vcpu->arch.cr3);
+ (void)kvm_set_cr3(vcpu, kvm_read_cr3(vcpu));
return 1;
}
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index ae943bb..5e4b120 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1135,7 +1135,7 @@ static void svm_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
switch (reg) {
case VCPU_EXREG_PDPTR:
BUG_ON(!npt_enabled);
- load_pdptrs(vcpu, vcpu->arch.walk_mmu, vcpu->arch.cr3);
+ load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
break;
default:
BUG();
@@ -2063,7 +2063,7 @@ static int nested_svm_vmexit(struct vcpu_svm *svm)
nested_vmcb->save.idtr = vmcb->save.idtr;
nested_vmcb->save.efer = svm->vcpu.arch.efer;
nested_vmcb->save.cr0 = kvm_read_cr0(&svm->vcpu);
- nested_vmcb->save.cr3 = svm->vcpu.arch.cr3;
+ nested_vmcb->save.cr3 = kvm_read_cr3(&svm->vcpu);
nested_vmcb->save.cr2 = vmcb->save.cr2;
nested_vmcb->save.cr4 = svm->vcpu.arch.cr4;
nested_vmcb->save.rflags = vmcb->save.rflags;
@@ -2256,7 +2256,7 @@ static bool nested_svm_vmrun(struct vcpu_svm *svm)
if (npt_enabled)
hsave->save.cr3 = vmcb->save.cr3;
else
- hsave->save.cr3 = svm->vcpu.arch.cr3;
+ hsave->save.cr3 = kvm_read_cr3(&svm->vcpu);
copy_vmcb_control_area(hsave, vmcb);
@@ -3507,7 +3507,7 @@ static void set_tdp_cr3(struct kvm_vcpu *vcpu, unsigned long root)
svm->vmcb->control.nested_cr3 = root;
/* Also sync guest cr3 here in case we live migrate */
- svm->vmcb->save.cr3 = vcpu->arch.cr3;
+ svm->vmcb->save.cr3 = kvm_read_cr3(vcpu);
force_new_asid(vcpu);
}
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 72cfdb7..92f2c72 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1940,7 +1940,7 @@ static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
if (enable_ept) {
eptp = construct_eptp(cr3);
vmcs_write64(EPT_POINTER, eptp);
- guest_cr3 = is_paging(vcpu) ? vcpu->arch.cr3 :
+ guest_cr3 = is_paging(vcpu) ? kvm_read_cr3(vcpu) :
vcpu->kvm->arch.ept_identity_map_addr;
ept_load_pdptrs(vcpu);
}
@@ -3184,8 +3184,9 @@ static int handle_cr(struct kvm_vcpu *vcpu)
case 1: /*mov from cr*/
switch (cr) {
case 3:
- kvm_register_write(vcpu, reg, vcpu->arch.cr3);
- trace_kvm_cr_read(cr, vcpu->arch.cr3);
+ val = kvm_read_cr3(vcpu);
+ kvm_register_write(vcpu, reg, val);
+ trace_kvm_cr_read(cr, val);
skip_emulated_instruction(vcpu);
return 1;
case 8:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ed373ba..4748499 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -469,8 +469,8 @@ static bool pdptrs_changed(struct kvm_vcpu *vcpu)
(unsigned long *)&vcpu->arch.regs_avail))
return true;
- gfn = (vcpu->arch.cr3 & ~31u) >> PAGE_SHIFT;
- offset = (vcpu->arch.cr3 & ~31u) & (PAGE_SIZE - 1);
+ gfn = (kvm_read_cr3(vcpu) & ~31u) >> PAGE_SHIFT;
+ offset = (kvm_read_cr3(vcpu) & ~31u) & (PAGE_SIZE - 1);
r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte),
PFERR_USER_MASK | PFERR_WRITE_MASK);
if (r < 0)
@@ -515,7 +515,7 @@ int kvm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
} else
#endif
if (is_pae(vcpu) && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
- vcpu->arch.cr3))
+ kvm_read_cr3(vcpu)))
return 1;
}
@@ -607,7 +607,8 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
return 1;
} else if (is_paging(vcpu) && (cr4 & X86_CR4_PAE)
&& ((cr4 ^ old_cr4) & pdptr_bits)
- && !load_pdptrs(vcpu, vcpu->arch.walk_mmu, vcpu->arch.cr3))
+ && !load_pdptrs(vcpu, vcpu->arch.walk_mmu,
+ kvm_read_cr3(vcpu)))
return 1;
if (cr4 & X86_CR4_VMXE)
@@ -627,7 +628,7 @@ EXPORT_SYMBOL_GPL(kvm_set_cr4);
int kvm_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
{
- if (cr3 == vcpu->arch.cr3 && !pdptrs_changed(vcpu)) {
+ if (cr3 == kvm_read_cr3(vcpu) && !pdptrs_changed(vcpu)) {
kvm_mmu_sync_roots(vcpu);
kvm_mmu_flush_tlb(vcpu);
return 0;
@@ -4070,7 +4071,7 @@ static unsigned long emulator_get_cr(int cr, struct kvm_vcpu *vcpu)
value = vcpu->arch.cr2;
break;
case 3:
- value = vcpu->arch.cr3;
+ value = kvm_read_cr3(vcpu);
break;
case 4:
value = kvm_read_cr4(vcpu);
@@ -5502,7 +5503,7 @@ int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
sregs->cr0 = kvm_read_cr0(vcpu);
sregs->cr2 = vcpu->arch.cr2;
- sregs->cr3 = vcpu->arch.cr3;
+ sregs->cr3 = kvm_read_cr3(vcpu);
sregs->cr4 = kvm_read_cr4(vcpu);
sregs->cr8 = kvm_get_cr8(vcpu);
sregs->efer = vcpu->arch.efer;
@@ -5570,7 +5571,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
kvm_x86_ops->set_gdt(vcpu, &dt);
vcpu->arch.cr2 = sregs->cr2;
- mmu_reset_needed |= vcpu->arch.cr3 != sregs->cr3;
+ mmu_reset_needed |= kvm_read_cr3(vcpu) != sregs->cr3;
vcpu->arch.cr3 = sregs->cr3;
kvm_set_cr8(vcpu, sregs->cr8);
@@ -5586,7 +5587,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
mmu_reset_needed |= kvm_read_cr4(vcpu) != sregs->cr4;
kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
if (!is_long_mode(vcpu) && is_pae(vcpu)) {
- load_pdptrs(vcpu, vcpu->arch.walk_mmu, vcpu->arch.cr3);
+ load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
mmu_reset_needed = 1;
}
--
1.7.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] KVM: Fetch guest cr3 from hardware on demand
2010-12-05 17:01 [PATCH 0/2] Keep cr3 cached in VMCS Avi Kivity
2010-12-05 17:01 ` [PATCH 1/2] KVM: Replace reads of vcpu->arch.cr3 by an accessor Avi Kivity
@ 2010-12-05 17:01 ` Avi Kivity
2010-12-06 16:41 ` Avi Kivity
1 sibling, 1 reply; 4+ messages in thread
From: Avi Kivity @ 2010-12-05 17:01 UTC (permalink / raw)
To: Marcelo Tosatti, kvm
Instead of syncing the guest cr3 every exit, which is expensince on vmx
with ept enabled, sync it only on demand.
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/kvm_cache_regs.h | 2 ++
arch/x86/kvm/svm.c | 5 +++++
arch/x86/kvm/vmx.c | 17 +++++++++++------
4 files changed, 20 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index cfbcbfa..4bd8daa 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -117,6 +117,7 @@ enum kvm_reg {
enum kvm_reg_ex {
VCPU_EXREG_PDPTR = NR_VCPU_REGS,
+ VCPU_EXREG_CR3,
};
enum {
@@ -532,6 +533,7 @@ struct kvm_x86_ops {
struct kvm_segment *var, int seg);
void (*get_cs_db_l_bits)(struct kvm_vcpu *vcpu, int *db, int *l);
void (*decache_cr0_guest_bits)(struct kvm_vcpu *vcpu);
+ void (*decache_cr3)(struct kvm_vcpu *vcpu);
void (*decache_cr4_guest_bits)(struct kvm_vcpu *vcpu);
void (*set_cr0)(struct kvm_vcpu *vcpu, unsigned long cr0);
void (*set_cr3)(struct kvm_vcpu *vcpu, unsigned long cr3);
diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index a6bf8db..3377d53 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -75,6 +75,8 @@ static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
{
+ if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
+ kvm_x86_ops->decache_cr3(vcpu);
return vcpu->arch.cr3;
}
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 5e4b120..91af472 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1286,6 +1286,10 @@ static void svm_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
{
}
+static void svm_decache_cr3(struct kvm_vcpu *vcpu)
+{
+}
+
static void svm_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
}
@@ -3683,6 +3687,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.get_cpl = svm_get_cpl,
.get_cs_db_l_bits = kvm_get_cs_db_l_bits,
.decache_cr0_guest_bits = svm_decache_cr0_guest_bits,
+ .decache_cr3 = svm_decache_cr3,
.decache_cr4_guest_bits = svm_decache_cr4_guest_bits,
.set_cr0 = svm_set_cr0,
.set_cr3 = svm_set_cr3,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 92f2c72..8d7b85a 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1817,6 +1817,14 @@ static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu)
vcpu->arch.cr0 |= vmcs_readl(GUEST_CR0) & cr0_guest_owned_bits;
}
+static void vmx_decache_cr3(struct kvm_vcpu *vcpu)
+{
+ /* Can only be called with EPT enabled */
+ if (enable_ept)
+ vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
+ __set_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail);
+}
+
static void vmx_decache_cr4_guest_bits(struct kvm_vcpu *vcpu)
{
ulong cr4_guest_owned_bits = vcpu->arch.cr4_guest_owned_bits;
@@ -3713,11 +3721,6 @@ static int vmx_handle_exit(struct kvm_vcpu *vcpu)
if (vmx->emulation_required && emulate_invalid_guest_state)
return handle_invalid_guest_state(vcpu);
- /* Access CR3 don't cause VMExit in paging mode, so we need
- * to sync with guest real CR3. */
- if (enable_ept && is_paging(vcpu))
- vcpu->arch.cr3 = vmcs_readl(GUEST_CR3);
-
if (exit_reason & VMX_EXIT_REASONS_FAILED_VMENTRY) {
vcpu->run->exit_reason = KVM_EXIT_FAIL_ENTRY;
vcpu->run->fail_entry.hardware_entry_failure_reason
@@ -4034,7 +4037,8 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu)
);
vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP)
- | (1 << VCPU_EXREG_PDPTR));
+ | (1 << VCPU_EXREG_PDPTR)
+ | (1 << VCPU_EXREG_CR3));
vcpu->arch.regs_dirty = 0;
vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
@@ -4306,6 +4310,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.get_cpl = vmx_get_cpl,
.get_cs_db_l_bits = vmx_get_cs_db_l_bits,
.decache_cr0_guest_bits = vmx_decache_cr0_guest_bits,
+ .decache_cr3 = vmx_decache_cr3,
.decache_cr4_guest_bits = vmx_decache_cr4_guest_bits,
.set_cr0 = vmx_set_cr0,
.set_cr3 = vmx_set_cr3,
--
1.7.1
^ permalink raw reply related [flat|nested] 4+ messages in thread