Re: [PATCH 3/8] KVM: Activate fpu on clts

Avi Kivity
2010-01-24T07:20:30Z

On 01/23/2010 08:56 PM, Marcelo Tosatti wrote:
> On Thu, Jan 21, 2010 at 03:31:47PM +0200, Avi Kivity wrote:
>
>> Assume that if the guest executes clts, it knows what it's doing, and load the
>> guest fpu to prevent an #NM exception.
>>
>> Signed-off-by: Avi Kivity<avi@redhat.com>
>> ---
>>
> Out of curiosity, previously you assumed lazy activation on clts was a
> win. Why undo it?
>

It wasn't so much assuming it's a win, it's more I was too lazy to find
out. But it was easy to see from the traces that clts is often followed
by #NM.

--
Do not meddle in the internals of kernels, for they are subtle and quick to panic.