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