linux-kernel - Re: [PATCH 0/4] KVM: x86: kvm_mwait_in

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Message-ID: <20170504175642.GH2246@HEDWIG.INI.CMU.EDU>
Date:   Thu, 4 May 2017 13:56:44 -0400
From:   "Gabriel L. Somlo" <gsomlo@...il.com>
To:     Radim Krčmář <rkrcmar@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Alexander Graf <agraf@...e.de>,
        "Michael S. Tsirkin" <mst@...hat.com>
Subject: Re: [PATCH 0/4] KVM: x86: kvm_mwait_in_guest() cleanup and fixes

Hi Radim,

On Wed, May 03, 2017 at 09:37:29PM +0200, Radim Krčmář wrote:
> kvm_mwait_in_guest() was overcomplicated and also missed one AMD bug
> that should prevent MWAIT pass through.
> 
> This series ignores errata that don't have any Linux bug defined;
> I know of two minor (not affecting the host) Core 2 errata:
>   AG36.  Split Locked Stores May not Trigger the Monitoring Hardware
>   AG106.  A REP STOS/MOVS to a MONITOR/MWAIT Address Range May Prevent
>           Triggering of the Monitoring Hardware
> 
> None of them are really worthy of a new condition if Linux never hit
> them ... we still have the OS X bug that Gabriel is hitting, but I'm ok
> with the original approach that sacrificed it for "greater good".

If I wanted to test this (e.g. with OS X 10.8 guests on several of my older
Mac boxes running Fedora), which git repo would you have me use? (The series
won't apply directly on top of git://git.kernel.org/pub/scm/virt/kvm/kvm.git).

Thanks much,
--Gabriel

> Radim Krčmář (4):
>   KVM: svm: prevent MWAIT in guest with erratum 400
>   KVM: x86: prevent MWAIT in guest with buggy MONITOR
>   KVM: x86: drop bogus MWAIT check
>   KVM: x86: simplify kvm_mwait_in_guest()
> 
>  arch/x86/kvm/x86.h | 33 +++------------------------------
>  1 file changed, 3 insertions(+), 30 deletions(-)
> 
> -- 
> 2.12.2
>