linux-kernel - Re: [PATCH] KVM: SVM: Add xsetbv intercept

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Message-ID: <4CFD0B06.9010308@redhat.com>
Date:	Mon, 06 Dec 2010 18:10:46 +0200
From:	Avi Kivity <avi@...hat.com>
To:	Joerg Roedel <joerg.roedel@....com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>, kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] KVM: SVM: Add xsetbv intercept

On 12/03/2010 06:42 PM, Joerg Roedel wrote:
> This patch implements the xsetbv intercept to the AMD part
> of KVM. This makes AVX usable in a save way for the guest on
> AVX capable AMD hardware.
> The patch is tested by using AVX in the guest and host in
> parallel and checking for data corruption. I also used the
> KVM xsave unit-tests and they all pass.
>

That is really strange.  You didn't need to do anything to get cpuid.avx 
recognized.  So running an older kvm on newer hardware will happily 
expose avx even though it's not supported.

We screwed up - we should have made cpuid.avx dependent on vendor support.

The patch itself looks fine, I just want to understand this point first.

-- 
error compiling committee.c: too many arguments to function

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