KVM: SVM: Advertise TSA CPUID bits to guests

Commit 31272abd5974b38ba312e9cf2ec2f09f9dd7dcba upstream.

Synthesize the TSA CPUID feature bits for guests. Set TSA_{SQ,L1}_NO on
unaffected machines.

Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: bp3tk0v

arch/x86/kvm/cpuid.c

@@ -758,6 +758,12 @@ void kvm_set_cpu_caps(void)
 	if (cpu_feature_enabled(X86_FEATURE_SRSO_NO))
 		kvm_cpu_cap_set(X86_FEATURE_SRSO_NO);
 
+	kvm_cpu_cap_mask(CPUID_8000_0021_EAX, F(VERW_CLEAR));
+
+	kvm_cpu_cap_init_kvm_defined(CPUID_8000_0021_ECX,
+		F(TSA_SQ_NO) | F(TSA_L1_NO)
+	);
+
 	/*
 	 * Hide RDTSCP and RDPID if either feature is reported as supported but
 	 * probing MSR_TSC_AUX failed.  This is purely a sanity check and
@@ -1243,7 +1249,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 		entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
 		break;
 	case 0x80000021:
-		entry->ebx = entry->ecx = entry->edx = 0;
+		entry->ebx = entry->edx = 0;
 		/*
 		 * Pass down these bits:
 		 *    EAX      0      NNDBP, Processor ignores nested data breakpoints
@@ -1259,6 +1265,7 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 			entry->eax |= BIT(2);
 		if (!static_cpu_has_bug(X86_BUG_NULL_SEG))
 			entry->eax |= BIT(6);
+		cpuid_entry_override(entry, CPUID_8000_0021_ECX);
 		break;
 	/*Add support for Centaur's CPUID instruction*/
 	case 0xC0000000:

arch/x86/kvm/reverse_cpuid.h

@@ -14,6 +14,7 @@
 enum kvm_only_cpuid_leafs {
 	CPUID_12_EAX	 = NCAPINTS,
 	CPUID_7_2_EDX,
+	CPUID_8000_0021_ECX,
 	NR_KVM_CPU_CAPS,
 
 	NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
@@ -45,6 +46,10 @@ enum kvm_only_cpuid_leafs {
 #define KVM_X86_FEATURE_BHI_CTRL	KVM_X86_FEATURE(CPUID_7_2_EDX, 4)
 #define X86_FEATURE_MCDT_NO		KVM_X86_FEATURE(CPUID_7_2_EDX, 5)
 
+/* CPUID level 0x80000021 (ECX) */
+#define KVM_X86_FEATURE_TSA_SQ_NO	KVM_X86_FEATURE(CPUID_8000_0021_ECX, 1)
+#define KVM_X86_FEATURE_TSA_L1_NO	KVM_X86_FEATURE(CPUID_8000_0021_ECX, 2)
+
 struct cpuid_reg {
 	u32 function;
 	u32 index;
@@ -71,6 +76,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
 	[CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX},
 	[CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX},
 	[CPUID_7_2_EDX]       = {         7, 2, CPUID_EDX},
+	[CPUID_8000_0021_ECX] = {0x80000021, 0, CPUID_ECX},
 };
 
 /*
@@ -107,6 +113,8 @@ static __always_inline u32 __feature_translate(int x86_feature)
 	KVM_X86_TRANSLATE_FEATURE(SGX2);
 	KVM_X86_TRANSLATE_FEATURE(RRSBA_CTRL);
 	KVM_X86_TRANSLATE_FEATURE(BHI_CTRL);
+	KVM_X86_TRANSLATE_FEATURE(TSA_SQ_NO);
+	KVM_X86_TRANSLATE_FEATURE(TSA_L1_NO);
 	default:
 		return x86_feature;
 	}