1 files changed, 82 insertions, 55 deletions

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 7456f9ad424b..06a278b3701d 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -54,7 +54,24 @@ static u32 xstate_required_size(u64 xstate_bv, bool compacted)
 
 #define F feature_bit
 
-static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
+static inline struct kvm_cpuid_entry2 *cpuid_entry2_find(
+	struct kvm_cpuid_entry2 *entries, int nent, u32 function, u32 index)
+{
+	struct kvm_cpuid_entry2 *e;
+	int i;
+
+	for (i = 0; i < nent; i++) {
+		e = &entries[i];
+
+		if (e->function == function && (e->index == index ||
+		    !(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX)))
+			return e;
+	}
+
+	return NULL;
+}
+
+static int kvm_check_cpuid(struct kvm_cpuid_entry2 *entries, int nent)
 {
 	struct kvm_cpuid_entry2 *best;
 
@@ -62,7 +79,7 @@ static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
 	 * The existing code assumes virtual address is 48-bit or 57-bit in the
 	 * canonical address checks; exit if it is ever changed.
 	 */
-	best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
+	best = cpuid_entry2_find(entries, nent, 0x80000008, 0);
 	if (best) {
 		int vaddr_bits = (best->eax & 0xff00) >> 8;
 
@@ -107,6 +124,13 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu)
 		(best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
 		best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
 
+	/*
+	 * save the feature bitmap to avoid cpuid lookup for every PV
+	 * operation
+	 */
+	if (best)
+		vcpu->arch.pv_cpuid.features = best->eax;
+
 	if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) {
 		best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 		if (best)
@@ -121,8 +145,6 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 	struct kvm_lapic *apic = vcpu->arch.apic;
 	struct kvm_cpuid_entry2 *best;
 
-	kvm_x86_ops.vcpu_after_set_cpuid(vcpu);
-
 	best = kvm_find_cpuid_entry(vcpu, 1, 0);
 	if (best && apic) {
 		if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
@@ -146,7 +168,9 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 	kvm_pmu_refresh(vcpu);
 	vcpu->arch.cr4_guest_rsvd_bits =
 	    __cr4_reserved_bits(guest_cpuid_has, vcpu);
-	kvm_x86_ops.update_exception_bitmap(vcpu);
+
+	/* Invoke the vendor callback only after the above state is updated. */
+	kvm_x86_ops.vcpu_after_set_cpuid(vcpu);
 }
 
 static int is_efer_nx(void)
@@ -186,7 +210,6 @@ int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
 not_found:
 	return 36;
 }
-EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
 
 /* when an old userspace process fills a new kernel module */
 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
@@ -194,46 +217,53 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 			     struct kvm_cpuid_entry __user *entries)
 {
 	int r, i;
-	struct kvm_cpuid_entry *cpuid_entries = NULL;
+	struct kvm_cpuid_entry *e = NULL;
+	struct kvm_cpuid_entry2 *e2 = NULL;
 
-	r = -E2BIG;
 	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
-		goto out;
+		return -E2BIG;
+
 	if (cpuid->nent) {
-		cpuid_entries = vmemdup_user(entries,
-					     array_size(sizeof(struct kvm_cpuid_entry),
-							cpuid->nent));
-		if (IS_ERR(cpuid_entries)) {
-			r = PTR_ERR(cpuid_entries);
-			goto out;
+		e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent));
+		if (IS_ERR(e))
+			return PTR_ERR(e);
+
+		e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT);
+		if (!e2) {
+			r = -ENOMEM;
+			goto out_free_cpuid;
 		}
 	}
 	for (i = 0; i < cpuid->nent; i++) {
-		vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
-		vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
-		vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
-		vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
-		vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
-		vcpu->arch.cpuid_entries[i].index = 0;
-		vcpu->arch.cpuid_entries[i].flags = 0;
-		vcpu->arch.cpuid_entries[i].padding[0] = 0;
-		vcpu->arch.cpuid_entries[i].padding[1] = 0;
-		vcpu->arch.cpuid_entries[i].padding[2] = 0;
+		e2[i].function = e[i].function;
+		e2[i].eax = e[i].eax;
+		e2[i].ebx = e[i].ebx;
+		e2[i].ecx = e[i].ecx;
+		e2[i].edx = e[i].edx;
+		e2[i].index = 0;
+		e2[i].flags = 0;
+		e2[i].padding[0] = 0;
+		e2[i].padding[1] = 0;
+		e2[i].padding[2] = 0;
 	}
-	vcpu->arch.cpuid_nent = cpuid->nent;
-	r = kvm_check_cpuid(vcpu);
+
+	r = kvm_check_cpuid(e2, cpuid->nent);
 	if (r) {
-		vcpu->arch.cpuid_nent = 0;
-		kvfree(cpuid_entries);
-		goto out;
+		kvfree(e2);
+		goto out_free_cpuid;
 	}
 
+	kvfree(vcpu->arch.cpuid_entries);
+	vcpu->arch.cpuid_entries = e2;
+	vcpu->arch.cpuid_nent = cpuid->nent;
+
 	cpuid_fix_nx_cap(vcpu);
 	kvm_update_cpuid_runtime(vcpu);
 	kvm_vcpu_after_set_cpuid(vcpu);
 
-	kvfree(cpuid_entries);
-out:
+out_free_cpuid:
+	kvfree(e);
+
 	return r;
 }
 
@@ -241,26 +271,32 @@ int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
 			      struct kvm_cpuid2 *cpuid,
 			      struct kvm_cpuid_entry2 __user *entries)
 {
+	struct kvm_cpuid_entry2 *e2 = NULL;
 	int r;
 
-	r = -E2BIG;
 	if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
-		goto out;
-	r = -EFAULT;
-	if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
-			   cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
-		goto out;
-	vcpu->arch.cpuid_nent = cpuid->nent;
-	r = kvm_check_cpuid(vcpu);
+		return -E2BIG;
+
+	if (cpuid->nent) {
+		e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent));
+		if (IS_ERR(e2))
+			return PTR_ERR(e2);
+	}
+
+	r = kvm_check_cpuid(e2, cpuid->nent);
 	if (r) {
-		vcpu->arch.cpuid_nent = 0;
-		goto out;
+		kvfree(e2);
+		return r;
 	}
 
+	kvfree(vcpu->arch.cpuid_entries);
+	vcpu->arch.cpuid_entries = e2;
+	vcpu->arch.cpuid_nent = cpuid->nent;
+
 	kvm_update_cpuid_runtime(vcpu);
 	kvm_vcpu_after_set_cpuid(vcpu);
-out:
-	return r;
+
+	return 0;
 }
 
 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
@@ -941,17 +977,8 @@ out_free:
 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
 					      u32 function, u32 index)
 {
-	struct kvm_cpuid_entry2 *e;
-	int i;
-
-	for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
-		e = &vcpu->arch.cpuid_entries[i];
-
-		if (e->function == function && (e->index == index ||
-		    !(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX)))
-			return e;
-	}
-	return NULL;
+	return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent,
+				 function, index);
 }
 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);