Even though it is preferrable to use SPEC_CTRL (represented by X86_FEATURE_AMD_SSBD) instead of VIRT_SPEC, VIRT_SPEC is always supported anyway because otherwise it would be impossible to migrate from old to new CPUs. Make this apparent in the result of KVM_GET_SUPPORTED_CPUID as well. Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> Reported-by: Eduardo Habkost <ehabkost@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/cpuid.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 145ec050d45d..5865bc73bbb5 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -747,11 +747,13 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); /* - * The preference is to use SPEC CTRL MSR instead of the - * VIRT_SPEC MSR. + * VIRT_SPEC is only implemented for AMD processors, + * but the host could set AMD_SSBD if it wanted even + * for Intel processors. */ - if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && - !boot_cpu_has(X86_FEATURE_AMD_SSBD)) + if ((boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) || + boot_cpu_has(X86_FEATURE_AMD_SSBD)) && + boot_cpu_has(X86_FEATURE_SVM)) entry->ebx |= F(VIRT_SSBD); break; } -- 1.8.3.1
