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From: David Matlack <dmatlack@google.com>
Date: Tue, 8 Nov 2016 14:12:24 -0800
Message-ID: <CALzav=dPGkW2oq2H5zBuO9Yc4VBZYFrYHBUfG5is0XDyenRW=w@mail.gmail.com>
Subject: Re: [PATCH v10 7/7] KVM: x86: virtualize cpuid faulting
To: Kyle Huey <me@kylehuey.com>
Cc: "Robert O'Callahan" <robert@ocallahan.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@redhat.com>,
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On Tue, Nov 8, 2016 at 10:39 AM, Kyle Huey <me@kylehuey.com> 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.
>
> Signed-off-by: Kyle Huey <khuey@kylehuey.com>

Reviewed-by: David Matlack <dmatlack@google.com>

(v10)