[PATCH 3/3] KVM: MMU: only update unsync page in invlpg path

From: Xiao Guangrong
Date: Sat May 15 2010 - 06:57:09 EST


Only unsync pages need updated at invlpg time since other shadow
pages are write-protected

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx>
---
arch/x86/kvm/paging_tmpl.h | 8 ++++++--
1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 71c73fe..dfbc8c7 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -463,6 +463,7 @@ out_unlock:
static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
{
struct kvm_shadow_walk_iterator iterator;
+ struct kvm_mmu_page *sp;
gpa_t pte_gpa = -1;
int level;
u64 *sptep;
@@ -474,10 +475,13 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
level = iterator.level;
sptep = iterator.sptep;

+ sp = page_header(__pa(sptep));
if (is_last_spte(*sptep, level)) {
- struct kvm_mmu_page *sp = page_header(__pa(sptep));
int offset, shift;

+ if (!sp->unsync)
+ break;
+
shift = PAGE_SHIFT -
(PT_LEVEL_BITS - PT64_LEVEL_BITS) * level;
offset = sp->role.quadrant << shift;
@@ -495,7 +499,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
break;
}

- if (!is_shadow_present_pte(*sptep))
+ if (!is_shadow_present_pte(*sptep) || !sp->unsync_children)
break;
}

--
1.6.1.2


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