Re: [PATCH v2 0/3] KVM: EFER.LMSLE cleanup

[Sean Christopherson]

On Tue, Sep 20, 2022, Borislav Petkov wrote:
> On Tue, Sep 20, 2022 at 01:59:19PM -0700, Jim Mattson wrote:
> > Jim Mattson (3):
> >   Revert "KVM: SVM: Allow EFER.LMSLE to be set with nested svm"
> >   x86/cpufeatures: Introduce X86_FEATURE_NO_LMSLE
> >   KVM: SVM: Unconditionally enumerate EferLmsleUnsupported
> 
> Why do you need those two if you revert the hack? After the revert,
> anything that tries to set LMSLE should get a #GP anyway, no?

Yes, but ideally KVM would explicitly tell the guest "you don't have LMSLE".
Probably a moot point, but at the same time I don't see a reason not to be
explicit.