Re: [PATCH v2 5/6] KVM/nVMX: Set the CPU_BASED_USE_MSR_BITMAPS if we have a valid L02 MSR bitmap

Ingo Molnar
2018-02-11T10:19:31Z

* David Woodhouse <dwmw@amazon.co.uk> wrote:

> From: KarimAllah Ahmed <karahmed@amazon.de>
>
> We either clear the CPU_BASED_USE_MSR_BITMAPS and end up intercepting all
> MSR accesses or create a valid L02 MSR bitmap and use that. This decision
> has to be made every time we evaluate whether we are going to generate the
> L02 MSR bitmap.
>
> Before commit 086e7d4118cc ("KVM: VMX: Allow direct access to MSR_IA32_SPEC_CTRL")
> this was probably OK since the decision was always identical. This is no
> longer the case now since the MSR bitmap might actually change once we
> decide to not intercept SPEC_CTRL and PRED_CMD.

Note, I fixed the changelog to refer to the correct upstream SHA1, which is:

d28b387fb74d: KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL

Thanks,

Ingo