Re: [PATCH v2 1/6] KVM: SVM: Use maxphyaddr in emulator RAX check for VMRUN/VMLOAD/VMSAVE

[Yosry Ahmed]

> > Right, but I am trying to have the #GP check for VMLOAD/VMSAVE behave
> > consistently with vls=1, whether it's done by the hardware or the
> > emulator.
>
> Consistency should not be an issue, since VLS cannot be enabled when
> the MAXPHYADDRs differ. VLS doesn't work in that scenario.

Why? It's only broken if VMLOAD/VMSAVE is executed with a GPA that
exceeds the guest's MAXPHYADDR, but not the host's, right? So only
broken if the guest is misbehaving.

Taking a step back, I am not disagreeing that VLS should not be used
with different MAXPHYADDRs, I am just saying it might be.

All that being said, I am fine with using cpuid_maxphyaddr(vcpu)
instead of kvm_host.maxphyaddr. Will wait for Sean's feedback to
figure out if a new version is needed.