Re: [PATCH 2/2] KVM: x86: Forbid KVM_SET_CPUID{,2} after KVM_RUN

From: Igor Mammedov
Date: Tue Jan 11 2022 - 03:00:46 EST


On Fri, 7 Jan 2022 19:15:43 +0100
Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:

> On 1/7/22 10:02, Vitaly Kuznetsov wrote:
> >
> > I'm again leaning towards an allowlist and currently I see only two
> > candidates:
> >
> > CPUID.01H.EBX bits 31:24 (initial LAPIC id)
> > CPUID.0BH.EDX (x2APIC id)
> >
> > Anything else I'm missing?
>
> I would also ignore completely CPUID leaves 03H, 04H, 0BH, 80000005h,
> 80000006h, 8000001Dh, 8000001Eh (cache and processor topology), just to
> err on the safe side.

on top of that,

1Fh

> We could change kvm_find_cpuid_entry to WARN if any of those leaves are
> passed.
>
> Paolo
>