Re: [PATCH v11 7/7] KVM: x86: virtualize cpuid faulting

[Nadav Amit]

> On Nov 10, 2016, at 3:40 PM, Kyle Huey <me@xxxxxxxxxxxx> wrote:
> 
> Hardware support for faulting on the cpuid instruction is not required to
> emulate it, because cpuid triggers a VM exit anyways. KVM handles the relevant
> MSRs (MSR_PLATFORM_INFO and MSR_MISC_FEATURES_ENABLE) and upon a
> cpuid-induced VM exit checks the cpuid faulting state and the CPL.
> kvm_require_cpl is even kind enough to inject the GP fault for us.

I think that for consistency you should also revise em_cpuid() of KVM
instruction emulator. Otherwise it may be a potential security
hazard (as far fetched as it currently seems).

Nadav