KVM: x86: Advertise fast REP string features inherent to the CPU

Fast zero-length REP MOVSB, fast short REP STOSB, and fast short REP
{CMPSB,SCASB} are inherent features of the processor that cannot be
hidden by the hypervisor. When these features are present on the host,
enumerate them in KVM_GET_SUPPORTED_CPUID.

Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220901211811.2883855-2-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

arch/x86/kvm/cpuid.c

@@ -664,8 +664,9 @@ void kvm_set_cpu_caps(void)
 		kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD);
 
 	kvm_cpu_cap_mask(CPUID_7_1_EAX,
-		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) | F(AMX_FP16) |
-		F(AVX_IFMA)
+		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) |
+		F(FZRM) | F(FSRS) | F(FSRC) |
+		F(AMX_FP16) | F(AVX_IFMA)
 	);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,