Re: [PATCH 2/3] KVM: x86: always expose VIRT_SSBD to guests

[Konrad Rzeszutek Wilk]

On Wed, Aug 21, 2019 at 10:26:41AM +0200, Paolo Bonzini wrote:
> 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.
> 
> While at it, reuse X86_FEATURE_* constants for the SVM leaf too.
> 
> However, we need to hide the bit on Intel processors, so move
> the setting to svm_set_supported_cpuid.
> 
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

Thank you!