[v2,10/10] KVM MMU: optimize sync/update unsync-page

Commit Message

Xiao Guangrong April 25, 2010, 7:02 a.m. UTC

None

Patch

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index add4658..3886207 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2697,7 +2697,8 @@  void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 
 restart:
 	hlist_for_each_entry_safe(sp, node, n, bucket, hash_link) {
-		if (sp->gfn != gfn || sp->role.direct || sp->role.invalid)
+		if (sp->gfn != gfn || sp->role.direct || sp->role.invalid ||
+		      sp->unsync)
 			continue;
 		pte_size = sp->role.cr4_pae ? 8 : 4;
 		misaligned = (offset ^ (offset + bytes - 1)) & ~(pte_size - 1);
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 38b4d23..b4fb737 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -474,16 +474,16 @@  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)) {
-			sp = page_header(__pa(sptep));
-
-			if (PTTYPE == 32) {
-				if (level == PT_DIRECTORY_LEVEL)
-					offset = PAGE_SHIFT - 4;
-				else
-					offset = PT64_LEVEL_BITS;
-				offset = sp->role.quadrant << offset;
-			}
+			if (!sp->unsync)
+				break;
+
+			WARN_ON(level != PT_PAGE_TABLE_LEVEL);
+
+			if (PTTYPE == 32)
+				offset = sp->role.quadrant << PT64_LEVEL_BITS;
+
 			gfn = sp->gfn;
 			offset = (sptep - sp->spt + offset) *
 					sizeof(pt_element_t);
@@ -498,7 +498,7 @@  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;
 	}
 
@@ -520,8 +520,7 @@  static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
 
 	mmu_guess_page_from_pte_write(vcpu, gfn_to_gpa(gfn) + offset, gentry);
 	spin_lock(&vcpu->kvm->mmu_lock);
-	if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter &&
-		sp->role.level == PT_PAGE_TABLE_LEVEL) {
+	if (atomic_read(&vcpu->kvm->arch.invlpg_counter) == invlpg_counter) {
 		++vcpu->kvm->stat.mmu_pte_updated;
 		FNAME(update_pte)(vcpu, sp, sptep, &gentry);
 	}