Re: [PATCH 0/4] XSA-52..54 follow-up

[George Dunlap <george.dunlap@eu.citrix.com>]

On 06/04/2013 11:00 AM, Keir Fraser wrote:
> On 04/06/2013 08:58, "Jan Beulich" <JBeulich@suse.com> wrote:
>
>> The first patch really isn't as much of a follow-up than what triggered
>> the security issues to be noticed in the first place.
>>
>> 1: x86: preserve FPU selectors for 32-bit guest code
>> 2: x86: fix XCR0 handling
>> 3: x86/xsave: adjust state management
>> 4: x86/fxsave: bring in line with recent xsave adjustments
>>
>> The first two I would see as candidates for 4.3 (as well as
>> subsequent backporting, albeit I realize that especially the first
>> one is non-trivial), while the third is code improvement only,
>> and the fourth is really just cleanup, and hence I'd be fine with
>> deferring them until after 4.3.
>>
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>
> I like the patches, 1 & 2 are good bug fixes.
> Acked-by: Keir Fraser <keir@xen.org>
>
> Patch #1 is quite scary though! I wonder really whether these long-lived
> issues must be fixed right now, let alone backported?

Yeah, I was going to say, with all this tricky code going in, including 
this one, and the XSA-55 (?) one that seems to have tons of tricky 
changes, whether it might not be a good idea to make sure we have at 
least 2 weeks of testing and another test day -- or, delay the test day 
Wednesday until we can get all of these in.

Jan, looking at the comments, it seems like 3 and 4 are more about 
performance than correctness?  I think those should probably wait until 
the 4.4 dev window opens up.

  -George