Re: [PATCH v2 1/2] KVM: SVM: Triple fault L1 on unintercepted EFER.SVME clear by L2

[Sean Christopherson]

On Fri, Feb 27, 2026, Yosry Ahmed wrote:
> > > What if we key off vcpu->wants_to_run?
> >
> > That crossed my mind too.
> >
> > > It's less protection against false positives from things like
> > > kvm_vcpu_reset() if it didn't leave nested before clearing EFER, but
> > > more protection against the #VMEXIT case you mentioned. Also should be
> > > much lower on the fugliness scale imo.
> >
> > Yeah, I had pretty much the exact same thought process and assessment.  I suggested
> > the WRMSR approach because I'm not sure how I feel about using wants_to_run for
> > functional behavior.  But after realizing that hooking WRMSR won't handle RSM,
> > I'm solidly against my WRMSR idea.
> >
> > Honestly, I'm leaning slightly towards dropping this patch entirely since it's
> > not a bug fix.  But I'm definitely not completely against it either.  So what if
> > we throw it in, but plan on reverting if there are any more problems (that aren't
> > obviously due to goofs elsewhere in KVM).
> 
> I am okay with that.
> 
> >
> > Is this what you were thinking?
> 
> Yeah, exactly.

Nice.  No need for a v3, I'll fixup when applying (it might be a while before
this gets any "thanks", as I want to land it behind all of the stable@ fixes).