Re: [PATCH 26/28] KVM: SVM: enable GMET and set it in MMU role

From: Sean Christopherson

Date: Thu Apr 30 2026 - 15:17:01 EST


On Thu, Apr 30, 2026, Paolo Bonzini wrote:
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index e7fdd7a9c280..3895d8794366 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -138,6 +138,9 @@ module_param(pause_filter_count_max, ushort, 0444);
> bool __ro_after_init npt_enabled = true;
> module_param_named(npt, npt_enabled, bool, 0444);
>
> +bool gmet_enabled = true;

This really should be hardcoded false, with no module param, until "enable GMET
for guests". Otherwise stopping here means KVM is over-reporting support.

I think the same goes for MBEC. IIUC, KVM doesn't fully support MBEC until
"KVM: nVMX: advertise MBEC to nested guests".