Re: [PATCH] kvm: x86: Report STIBP on GET_SUPPORTED_CPUID

[Jim Mattson]

On Wed, Dec 5, 2018 at 11:19 AM Eduardo Habkost <ehabkost@xxxxxxxxxx> wrote:
>
> Months ago, we have added code to allow direct access to MSR_IA32_SPEC_CTRL
> to the guest, which makes STIBP available to guests.  This was implemented
> by commits d28b387fb74d ("KVM/VMX: Allow direct access to
> MSR_IA32_SPEC_CTRL") and b2ac58f90540 ("KVM/SVM: Allow direct access to
> MSR_IA32_SPEC_CTRL").
>
> However, we never updated GET_SUPPORTED_CPUID to let userspace know that
> STIBP can be enabled in CPUID.  Fix that by updating
> kvm_cpuid_8000_0008_ebx_x86_features and kvm_cpuid_7_0_edx_x86_features.
>
> Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx>
Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>