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Date: Mon, 13 Jun 2011 11:45:34 +0300
From: Avi Kivity <avi@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH][uq/master] kvm: x86: Save/restore FPU OP,
	IP and DP
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To: Jan Kiszka <jan.kiszka@web.de>
Cc: Christophe Fergeau <cfergeau@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>, qemu-devel <qemu-devel@nongnu.org>, kvm <kvm@vger.kernel.org>, Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

On 06/11/2011 12:23 PM, Jan Kiszka wrote:
> From: Jan Kiszka<jan.kiszka@siemens.com>
>
> These FPU states are properly maintained by KVM but not yet by TCG. So
> far we unconditionally set them to 0 in the guest which may cause
> state corruptions - not only during migration.
>
>
> -#define CPU_SAVE_VERSION 12
> +#define CPU_SAVE_VERSION 13
>

Incrementing the version number seems excessive - I can't imagine a 
real-life guest will break due to fp pointer corruption

However, I don't think we have a mechanism for optional state.  We 
discussed this during the 18th VMState Subsection Symposium and IIRC 
agreed to re-raise the issue when we encountered it, which appears to be 
now.

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