X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=arch%2Fx86%2Fkvm%2Fmmu.c;h=50fe8541ed3906f5f8f3991d26b2c084adbac9d6;hb=2aaf65e8c40468b198b709a765abe311f91c1a1d;hp=5f97dbd242916a7cadebde539d964e29d7bcabcb;hpb=988a2cae6a3c0dea6df59808a935a9a697bfc28c;p=safe%2Fjmp%2Flinux-2.6

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 5f97dbd..50fe854 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -250,6 +250,15 @@ static int is_rmap_spte(u64 pte)
 	return is_shadow_present_pte(pte);
 }
 
+static int is_last_spte(u64 pte, int level)
+{
+	if (level == PT_PAGE_TABLE_LEVEL)
+		return 1;
+	if (level == PT_DIRECTORY_LEVEL && is_large_pte(pte))
+		return 1;
+	return 0;
+}
+
 static pfn_t spte_to_pfn(u64 pte)
 {
 	return (pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT;
@@ -1313,25 +1322,17 @@ static void kvm_mmu_page_unlink_children(struct kvm *kvm,
 
 	pt = sp->spt;
 
-	if (sp->role.level == PT_PAGE_TABLE_LEVEL) {
-		for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
-			if (is_shadow_present_pte(pt[i]))
-				rmap_remove(kvm, &pt[i]);
-			pt[i] = shadow_trap_nonpresent_pte;
-		}
-		return;
-	}
-
 	for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
 		ent = pt[i];
 
 		if (is_shadow_present_pte(ent)) {
-			if (!is_large_pte(ent)) {
+			if (!is_last_spte(ent, sp->role.level)) {
 				ent &= PT64_BASE_ADDR_MASK;
 				mmu_page_remove_parent_pte(page_header(ent),
 							   &pt[i]);
 			} else {
-				--kvm->stat.lpages;
+				if (is_large_pte(ent))
+					--kvm->stat.lpages;
 				rmap_remove(kvm, &pt[i]);
 			}
 		}
@@ -2381,8 +2382,7 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
 
 	pte = *spte;
 	if (is_shadow_present_pte(pte)) {
-		if (sp->role.level == PT_PAGE_TABLE_LEVEL ||
-		    is_large_pte(pte))
+		if (is_last_spte(pte, sp->role.level))
 			rmap_remove(vcpu->kvm, spte);
 		else {
 			child = page_header(pte & PT64_BASE_ADDR_MASK);
@@ -2673,8 +2673,9 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code)
 		++vcpu->stat.mmio_exits;
 		return 0;
 	case EMULATE_FAIL:
-		kvm_report_emulation_failure(vcpu, "pagetable");
-		return 1;
+		vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+		vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION;
+		return 0;
 	default:
 		BUG();
 	}
@@ -3044,6 +3045,55 @@ static gva_t canonicalize(gva_t gva)
 	return gva;
 }
 
+
+typedef void (*inspect_spte_fn) (struct kvm *kvm, struct kvm_mmu_page *sp,
+				 u64 *sptep);
+
+static void __mmu_spte_walk(struct kvm *kvm, struct kvm_mmu_page *sp,
+			    inspect_spte_fn fn)
+{
+	int i;
+
+	for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
+		u64 ent = sp->spt[i];
+
+		if (is_shadow_present_pte(ent)) {
+			if (sp->role.level > 1 && !is_large_pte(ent)) {
+				struct kvm_mmu_page *child;
+				child = page_header(ent & PT64_BASE_ADDR_MASK);
+				__mmu_spte_walk(kvm, child, fn);
+			}
+			if (sp->role.level == 1)
+				fn(kvm, sp, &sp->spt[i]);
+		}
+	}
+}
+
+static void mmu_spte_walk(struct kvm_vcpu *vcpu, inspect_spte_fn fn)
+{
+	int i;
+	struct kvm_mmu_page *sp;
+
+	if (!VALID_PAGE(vcpu->arch.mmu.root_hpa))
+		return;
+	if (vcpu->arch.mmu.shadow_root_level == PT64_ROOT_LEVEL) {
+		hpa_t root = vcpu->arch.mmu.root_hpa;
+		sp = page_header(root);
+		__mmu_spte_walk(vcpu->kvm, sp, fn);
+		return;
+	}
+	for (i = 0; i < 4; ++i) {
+		hpa_t root = vcpu->arch.mmu.pae_root[i];
+
+		if (root && VALID_PAGE(root)) {
+			root &= PT64_BASE_ADDR_MASK;
+			sp = page_header(root);
+			__mmu_spte_walk(vcpu->kvm, sp, fn);
+		}
+	}
+	return;
+}
+
 static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
 				gva_t va, int level)
 {
@@ -3059,12 +3109,7 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
 
 		va = canonicalize(va);
 		if (level > 1) {
-			if (ent == shadow_notrap_nonpresent_pte)
-				printk(KERN_ERR "audit: (%s) nontrapping pte"
-				       " in nonleaf level: levels %d gva %lx"
-				       " level %d pte %llx\n", audit_msg,
-				       vcpu->arch.mmu.root_level, va, level, ent);
-			else
+			if (is_shadow_present_pte(ent))
 				audit_mappings_page(vcpu, ent, va, level - 1);
 		} else {
 			gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
@@ -3072,6 +3117,11 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
 			pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
 			hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
 
+			if (is_error_pfn(pfn)) {
+				kvm_release_pfn_clean(pfn);
+				continue;
+			}
+
 			if (is_shadow_present_pte(ent)
 			    && (ent & PT64_BASE_ADDR_MASK) != hpa)
 				printk(KERN_ERR "xx audit error: (%s) levels %d"
@@ -3136,9 +3186,47 @@ static int count_rmaps(struct kvm_vcpu *vcpu)
 	return nmaps;
 }
 
-static int count_writable_mappings(struct kvm_vcpu *vcpu)
+void inspect_spte_has_rmap(struct kvm *kvm, struct kvm_mmu_page *sp, u64 *sptep)
+{
+	unsigned long *rmapp;
+	struct kvm_mmu_page *rev_sp;
+	gfn_t gfn;
+
+	if (*sptep & PT_WRITABLE_MASK) {
+		rev_sp = page_header(__pa(sptep));
+		gfn = rev_sp->gfns[sptep - rev_sp->spt];
+
+		if (!gfn_to_memslot(kvm, gfn)) {
+			if (!printk_ratelimit())
+				return;
+			printk(KERN_ERR "%s: no memslot for gfn %ld\n",
+					 audit_msg, gfn);
+			printk(KERN_ERR "%s: index %ld of sp (gfn=%lx)\n",
+					audit_msg, sptep - rev_sp->spt,
+					rev_sp->gfn);
+			dump_stack();
+			return;
+		}
+
+		rmapp = gfn_to_rmap(kvm, rev_sp->gfns[sptep - rev_sp->spt], 0);
+		if (!*rmapp) {
+			if (!printk_ratelimit())
+				return;
+			printk(KERN_ERR "%s: no rmap for writable spte %llx\n",
+					 audit_msg, *sptep);
+			dump_stack();
+		}
+	}
+
+}
+
+void audit_writable_sptes_have_rmaps(struct kvm_vcpu *vcpu)
+{
+	mmu_spte_walk(vcpu, inspect_spte_has_rmap);
+}
+
+static void check_writable_mappings_rmap(struct kvm_vcpu *vcpu)
 {
-	int nmaps = 0;
 	struct kvm_mmu_page *sp;
 	int i;
 
@@ -3155,20 +3243,16 @@ static int count_writable_mappings(struct kvm_vcpu *vcpu)
 				continue;
 			if (!(ent & PT_WRITABLE_MASK))
 				continue;
-			++nmaps;
+			inspect_spte_has_rmap(vcpu->kvm, sp, &pt[i]);
 		}
 	}
-	return nmaps;
+	return;
 }
 
 static void audit_rmap(struct kvm_vcpu *vcpu)
 {
-	int n_rmap = count_rmaps(vcpu);
-	int n_actual = count_writable_mappings(vcpu);
-
-	if (n_rmap != n_actual)
-		printk(KERN_ERR "%s: (%s) rmap %d actual %d\n",
-		       __func__, audit_msg, n_rmap, n_actual);
+	check_writable_mappings_rmap(vcpu);
+	count_rmaps(vcpu);
 }
 
 static void audit_write_protection(struct kvm_vcpu *vcpu)
@@ -3176,20 +3260,28 @@ static void audit_write_protection(struct kvm_vcpu *vcpu)
 	struct kvm_mmu_page *sp;
 	struct kvm_memory_slot *slot;
 	unsigned long *rmapp;
+	u64 *spte;
 	gfn_t gfn;
 
 	list_for_each_entry(sp, &vcpu->kvm->arch.active_mmu_pages, link) {
 		if (sp->role.direct)
 			continue;
+		if (sp->unsync)
+			continue;
 
 		gfn = unalias_gfn(vcpu->kvm, sp->gfn);
 		slot = gfn_to_memslot_unaliased(vcpu->kvm, sp->gfn);
 		rmapp = &slot->rmap[gfn - slot->base_gfn];
-		if (*rmapp)
-			printk(KERN_ERR "%s: (%s) shadow page has writable"
-			       " mappings: gfn %lx role %x\n",
+
+		spte = rmap_next(vcpu->kvm, rmapp, NULL);
+		while (spte) {
+			if (*spte & PT_WRITABLE_MASK)
+				printk(KERN_ERR "%s: (%s) shadow page has "
+				"writable mappings: gfn %lx role %x\n",
 			       __func__, audit_msg, sp->gfn,
 			       sp->role.word);
+			spte = rmap_next(vcpu->kvm, rmapp, spte);
+		}
 	}
 }
 
@@ -3201,7 +3293,9 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg)
 	audit_msg = msg;
 	audit_rmap(vcpu);
 	audit_write_protection(vcpu);
-	audit_mappings(vcpu);
+	if (strcmp("pre pte write", audit_msg) != 0)
+		audit_mappings(vcpu);
+	audit_writable_sptes_have_rmaps(vcpu);
 	dbg = olddbg;
 }