1 files changed, 26 insertions, 32 deletions

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c42613cfb5ba..fe03bd978761 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -208,30 +208,6 @@ static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu)
 	kvm_mmu_after_set_cpuid(vcpu);
 }
 
-static int is_efer_nx(void)
-{
-	return host_efer & EFER_NX;
-}
-
-static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
-{
-	int i;
-	struct kvm_cpuid_entry2 *e, *entry;
-
-	entry = NULL;
-	for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
-		e = &vcpu->arch.cpuid_entries[i];
-		if (e->function == 0x80000001) {
-			entry = e;
-			break;
-		}
-	}
-	if (entry && cpuid_entry_has(entry, X86_FEATURE_NX) && !is_efer_nx()) {
-		cpuid_entry_clear(entry, X86_FEATURE_NX);
-		printk(KERN_INFO "kvm: guest NX capability removed\n");
-	}
-}
-
 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best;
@@ -302,7 +278,6 @@ int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 	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);
 
@@ -401,7 +376,6 @@ static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask)
 
 void kvm_set_cpu_caps(void)
 {
-	unsigned int f_nx = is_efer_nx() ? F(NX) : 0;
 #ifdef CONFIG_X86_64
 	unsigned int f_gbpages = F(GBPAGES);
 	unsigned int f_lm = F(LM);
@@ -515,7 +489,7 @@ void kvm_set_cpu_caps(void)
 		F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
 		F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 		F(PAT) | F(PSE36) | 0 /* Reserved */ |
-		f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
+		F(NX) | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
 		F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) |
 		0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW)
 	);
@@ -765,7 +739,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 
 		edx.split.num_counters_fixed = min(cap.num_counters_fixed, MAX_FIXED_COUNTERS);
 		edx.split.bit_width_fixed = cap.bit_width_fixed;
-		edx.split.anythread_deprecated = 1;
+		if (cap.version)
+			edx.split.anythread_deprecated = 1;
 		edx.split.reserved1 = 0;
 		edx.split.reserved2 = 0;
 
@@ -940,8 +915,21 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
 		unsigned phys_as = entry->eax & 0xff;
 
-		if (!g_phys_as)
+		/*
+		 * If TDP (NPT) is disabled use the adjusted host MAXPHYADDR as
+		 * the guest operates in the same PA space as the host, i.e.
+		 * reductions in MAXPHYADDR for memory encryption affect shadow
+		 * paging, too.
+		 *
+		 * If TDP is enabled but an explicit guest MAXPHYADDR is not
+		 * provided, use the raw bare metal MAXPHYADDR as reductions to
+		 * the HPAs do not affect GPAs.
+		 */
+		if (!tdp_enabled)
+			g_phys_as = boot_cpu_data.x86_phys_bits;
+		else if (!g_phys_as)
 			g_phys_as = phys_as;
+
 		entry->eax = g_phys_as | (virt_as << 8);
 		entry->edx = 0;
 		cpuid_entry_override(entry, CPUID_8000_0008_EBX);
@@ -964,12 +952,18 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 	case 0x8000001a:
 	case 0x8000001e:
 		break;
-	/* Support memory encryption cpuid if host supports it */
 	case 0x8000001F:
-		if (!kvm_cpu_cap_has(X86_FEATURE_SEV))
+		if (!kvm_cpu_cap_has(X86_FEATURE_SEV)) {
 			entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
-		else
+		} else {
 			cpuid_entry_override(entry, CPUID_8000_001F_EAX);
+
+			/*
+			 * Enumerate '0' for "PA bits reduction", the adjusted
+			 * MAXPHYADDR is enumerated directly (see 0x80000008).
+			 */
+			entry->ebx &= ~GENMASK(11, 6);
+		}
 		break;
 	/*Add support for Centaur's CPUID instruction*/
 	case 0xC0000000: