Re: [PATCH 22/22] KVM: nSVM: enable GMET for guests

[Paolo Bonzini]

On Tue, Mar 24, 2026 at 8:57 PM Jon Kohler <jon@xxxxxxxxxxx> wrote:
> On Mar 20, 2026, at 8:09 PM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> > vmcb02->control.nested_ctl &= ~SVM_NESTED_CTL_GMET_ENABLE;
> > if (guest_cpu_cap_has(vcpu, X86_FEATURE_GMET))
> >      vmcb02->control.nested_ctl |=
> >            (svm->nested.ctl.nested_ctl & SVM_NESTED_CTL_GMET_ENABLE);

The issue is with nNPT disabled; these four lines of code have to be
moved inside the "if (nested_npt_enabled(svm))".

(The giveaway is the kvmmmu:fast_page_fault event in the trace, which
never appears with shadow paging).

I have fixed Kai's reported issues and EPT page tests, and will post
the next version after doing some more testing.

Paolo