KVM: MMU: audit: check whether have unsync sps after root sync

After root synced, all unsync sps are synced, this patch add a check to make
sure it's no unsync sps in VCPU's page table
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/mmu.c

@@ -53,14 +53,18 @@ enum {
 	AUDIT_PRE_PAGE_FAULT,
 	AUDIT_POST_PAGE_FAULT,
 	AUDIT_PRE_PTE_WRITE,
-	AUDIT_POST_PTE_WRITE
+	AUDIT_POST_PTE_WRITE,
+	AUDIT_PRE_SYNC,
+	AUDIT_POST_SYNC
 };
 
 char *audit_point_name[] = {
 	"pre page fault",
 	"post page fault",
 	"pre pte write",
-	"post pte write"
+	"post pte write",
+	"pre sync",
+	"post sync"
 };
 
 #undef MMU_DEBUG
@@ -2516,6 +2520,8 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu)
 
 	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
 		return;
+
+	trace_kvm_mmu_audit(vcpu, AUDIT_PRE_SYNC);
 	if (vcpu->arch.mmu.root_level == PT64_ROOT_LEVEL) {
 		hpa_t root = vcpu->arch.mmu.root_hpa;
 		sp = page_header(root);
@@ -2531,6 +2537,7 @@ static void mmu_sync_roots(struct kvm_vcpu *vcpu)
 			mmu_sync_children(vcpu, sp);
 		}
 	}
+	trace_kvm_mmu_audit(vcpu, AUDIT_POST_SYNC);
 }
 
 void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)

arch/x86/kvm/mmu_audit.c

@@ -164,6 +164,14 @@ static void audit_sptes_have_rmaps(struct kvm_vcpu *vcpu, u64 *sptep, int level)
 		inspect_spte_has_rmap(vcpu->kvm, sptep);
 }
 
+static void audit_spte_after_sync(struct kvm_vcpu *vcpu, u64 *sptep, int level)
+{
+	struct kvm_mmu_page *sp = page_header(__pa(sptep));
+
+	if (audit_point == AUDIT_POST_SYNC && sp->unsync)
+		audit_printk("meet unsync sp(%p) after sync root.\n", sp);
+}
+
 static void check_mappings_rmap(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	int i;
@@ -179,7 +187,7 @@ static void check_mappings_rmap(struct kvm *kvm, struct kvm_mmu_page *sp)
 	}
 }
 
-void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp)
+static void audit_write_protection(struct kvm *kvm, struct kvm_mmu_page *sp)
 {
 	struct kvm_memory_slot *slot;
 	unsigned long *rmapp;
@@ -215,6 +223,7 @@ static void audit_spte(struct kvm_vcpu *vcpu, u64 *sptep, int level)
 {
 	audit_sptes_have_rmaps(vcpu, sptep, level);
 	audit_mappings(vcpu, sptep, level);
+	audit_spte_after_sync(vcpu, sptep, level);
 }
 
 static void audit_vcpu_spte(struct kvm_vcpu *vcpu)