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authorMarcelo Tosatti <mtosatti@redhat.com>2008-12-01 22:32:05 -0200
committerAvi Kivity <avi@redhat.com>2008-12-31 16:55:44 +0200
commitad218f85e388e8ca816ff09d91c246cd014c53a8 (patch)
tree73fff9d1b3f01e760c2da8bc2276c1a74f4a36e4 /arch/x86
parent6cffe8ca4a2adf1ac5003d9cad08fe4434d6eee0 (diff)
KVM: MMU: prepopulate the shadow on invlpg
If the guest executes invlpg, peek into the pagetable and attempt to prepopulate the shadow entry. Also stop dirty fault updates from interfering with the fork detector. 2% improvement on RHEL3/AIM7. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/kvm_host.h3
-rw-r--r--arch/x86/kvm/mmu.c25
-rw-r--r--arch/x86/kvm/paging_tmpl.h25
-rw-r--r--arch/x86/kvm/x86.c2
4 files changed, 40 insertions, 15 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 65b1ed29569..97215a458e5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -602,7 +602,8 @@ unsigned long segment_base(u16 selector);
void kvm_mmu_flush_tlb(struct kvm_vcpu *vcpu);
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
- const u8 *new, int bytes);
+ const u8 *new, int bytes,
+ bool guest_initiated);
int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva);
void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu);
int kvm_mmu_load(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index cbac9e4b156..863baf70506 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2441,7 +2441,8 @@ static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
}
void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
- const u8 *new, int bytes)
+ const u8 *new, int bytes,
+ bool guest_initiated)
{
gfn_t gfn = gpa >> PAGE_SHIFT;
struct kvm_mmu_page *sp;
@@ -2467,15 +2468,17 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
kvm_mmu_free_some_pages(vcpu);
++vcpu->kvm->stat.mmu_pte_write;
kvm_mmu_audit(vcpu, "pre pte write");
- if (gfn == vcpu->arch.last_pt_write_gfn
- && !last_updated_pte_accessed(vcpu)) {
- ++vcpu->arch.last_pt_write_count;
- if (vcpu->arch.last_pt_write_count >= 3)
- flooded = 1;
- } else {
- vcpu->arch.last_pt_write_gfn = gfn;
- vcpu->arch.last_pt_write_count = 1;
- vcpu->arch.last_pte_updated = NULL;
+ if (guest_initiated) {
+ if (gfn == vcpu->arch.last_pt_write_gfn
+ && !last_updated_pte_accessed(vcpu)) {
+ ++vcpu->arch.last_pt_write_count;
+ if (vcpu->arch.last_pt_write_count >= 3)
+ flooded = 1;
+ } else {
+ vcpu->arch.last_pt_write_gfn = gfn;
+ vcpu->arch.last_pt_write_count = 1;
+ vcpu->arch.last_pte_updated = NULL;
+ }
}
index = kvm_page_table_hashfn(gfn);
bucket = &vcpu->kvm->arch.mmu_page_hash[index];
@@ -2615,9 +2618,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_page_fault);
void kvm_mmu_invlpg(struct kvm_vcpu *vcpu, gva_t gva)
{
- spin_lock(&vcpu->kvm->mmu_lock);
vcpu->arch.mmu.invlpg(vcpu, gva);
- spin_unlock(&vcpu->kvm->mmu_lock);
kvm_mmu_flush_tlb(vcpu);
++vcpu->stat.invlpg;
}
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index e644d81979b..d2064015421 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -82,6 +82,7 @@ struct shadow_walker {
int *ptwrite;
pfn_t pfn;
u64 *sptep;
+ gpa_t pte_gpa;
};
static gfn_t gpte_to_gfn(pt_element_t gpte)
@@ -222,7 +223,7 @@ walk:
if (ret)
goto walk;
pte |= PT_DIRTY_MASK;
- kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte));
+ kvm_mmu_pte_write(vcpu, pte_gpa, (u8 *)&pte, sizeof(pte), 0);
walker->ptes[walker->level - 1] = pte;
}
@@ -468,8 +469,15 @@ static int FNAME(shadow_invlpg_entry)(struct kvm_shadow_walk *_sw,
struct kvm_vcpu *vcpu, u64 addr,
u64 *sptep, int level)
{
+ struct shadow_walker *sw =
+ container_of(_sw, struct shadow_walker, walker);
if (level == PT_PAGE_TABLE_LEVEL) {
+ struct kvm_mmu_page *sp = page_header(__pa(sptep));
+
+ sw->pte_gpa = (sp->gfn << PAGE_SHIFT);
+ sw->pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);
+
if (is_shadow_present_pte(*sptep))
rmap_remove(vcpu->kvm, sptep);
set_shadow_pte(sptep, shadow_trap_nonpresent_pte);
@@ -482,11 +490,26 @@ static int FNAME(shadow_invlpg_entry)(struct kvm_shadow_walk *_sw,
static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
{
+ pt_element_t gpte;
struct shadow_walker walker = {
.walker = { .entry = FNAME(shadow_invlpg_entry), },
+ .pte_gpa = -1,
};
+ spin_lock(&vcpu->kvm->mmu_lock);
walk_shadow(&walker.walker, vcpu, gva);
+ spin_unlock(&vcpu->kvm->mmu_lock);
+ if (walker.pte_gpa == -1)
+ return;
+ if (kvm_read_guest_atomic(vcpu->kvm, walker.pte_gpa, &gpte,
+ sizeof(pt_element_t)))
+ return;
+ if (is_present_pte(gpte) && (gpte & PT_ACCESSED_MASK)) {
+ if (mmu_topup_memory_caches(vcpu))
+ return;
+ kvm_mmu_pte_write(vcpu, walker.pte_gpa, (const u8 *)&gpte,
+ sizeof(pt_element_t), 0);
+ }
}
static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 774db00d2db..ba102879de3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2046,7 +2046,7 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
ret = kvm_write_guest(vcpu->kvm, gpa, val, bytes);
if (ret < 0)
return 0;
- kvm_mmu_pte_write(vcpu, gpa, val, bytes);
+ kvm_mmu_pte_write(vcpu, gpa, val, bytes, 1);
return 1;
}