Messages in this thread | | | Date | Wed, 21 Sep 2022 11:28:24 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2 0/3] KVM: EFER.LMSLE cleanup |
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On Tue, Sep 20, 2022 at 09:36:18PM +0000, Sean Christopherson wrote: > 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.
Yes but...
On Tue, Sep 20, 2022 at 02:36:34PM -0700, Jim Mattson wrote: > Reporting that CPUID bit gives us the right to raise #GP. AMD CPUs > (going way back) that don't report EferLmsleUnsupported do not raise > #GP.
... what does "gives us the right" mean exactly?
I'm pretty sure I'm missing something about how KVM works but wouldn't it raise a guest #GP when the guest tries to set an unsupported EFER bit? I.e., why do you need to explicitly do
kvm_cpu_cap_set(X86_FEATURE_NO_LMSLE);
and not handle this like any other EFER reserved bit?
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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