KVM: MMU: only update unsync page in invlpg path

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

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 22f13797f521..0671d7a29c3c 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -461,6 +461,7 @@ 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;
@@ -472,10 +473,13 @@ 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;
@@ -493,7 +497,7 @@ 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;
         }