Re: [PATCH v4] KVM: X86: Allow userspace to define the microcode version

From: Borislav Petkov
Date: Tue Feb 27 2018 - 04:43:36 EST


On Tue, Feb 27, 2018 at 09:38:12AM +0100, Paolo Bonzini wrote:
> On 27/02/2018 03:35, Wanpeng Li wrote:
> > From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> >
> > Linux (among the others) has checks to make sure that certain features
> > aren't enabled on a certain family/model/stepping if the microcode version
> > isn't greater than or equal to a known good version.
> >
> > By exposing the real microcode version, we're preventing buggy guests that
> > don't check that they are running virtualized (i.e., they should trust the
> > hypervisor) from disabling features that are effectively not buggy.
> >
> > Suggested-by: Filippo Sironi <sironi@xxxxxxxxx>
> > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> > Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
> > Cc: Liran Alon <liran.alon@xxxxxxxxxx>
> > Cc: Nadav Amit <nadav.amit@xxxxxxxxx>
> > Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> > ---
> > v3 -> v4:
> > * add the shifts back
>
> Please wait for a review instead of pushing new versions continuously.

... and pls CC me on your submissions.

Thx.

--
Regards/Gruss,
Boris.

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