From mboxrd@z Thu Jan 1 00:00:00 1970 From: Weidong Han Subject: Re: [PATCH 2/4] XSAVE/XRSTOR: enable guest save/restore Date: Tue, 31 Aug 2010 20:28:09 +0800 Message-ID: <4C7CF559.5010805@intel.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: Jeremy Fitzhardinge , Xen-devel , Jan Beulich List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > On 31/08/2010 08:08, "Jan Beulich" wrote: > > >>> #define VGCF_I387_VALID (1<<0) >>> #define VGCF_IN_KERNEL (1<<2) >>> #define _VGCF_i387_valid 0 >>> >> As Keir already indicated, you can't change the size of this structure. >> I'd say that it was a mistake to include the FPU state directly here in >> the first place - you'll have to invent a mechanism to (compatibly) >> not make this a requirement anymore. E.g. use the reserved part of >> fpu_ctxt to store a guest handle referring to the actual area: This >> ought to work as (iirc) the structure is used as input only >> (VCPUOP_initialize) outside of the tools, and the domctl interface is >> allowed to change as long as you don't break compatibility with >> stored data (saved guest images). >> > > I would agree but for the fact that it appears that XSAVE is only supported > for HVM guests right now. Hence this whole rigmarole is actually currently > pointless, since HVM guests do not initialise/save/restore the > vcpu_guest_context structure. I think probably this bit of the patch could > simply be dropped until PV support is added. > > -- Keir > > I will send out other patches soon, and revise this patch later. Regards, Weidong > >