From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: Test if on newer xen all SSE2 and SSE3 instructions are effectively working Date: Thu, 21 Nov 2013 15:22:06 +0000 Message-ID: <528E251E.1020907@citrix.com> References: <528DE5D7.60701@m2r.biz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Fabio Fantoni Cc: George Dunlap , xen-devel , "Dong, Eddie" , "Nakajima, Jun" , Jan Beulich List-Id: xen-devel@lists.xenproject.org On 21/11/13 15:12, George Dunlap wrote: > On Thu, Nov 21, 2013 at 10:52 AM, Fabio Fantoni wrote: >> I'm trying to test if on newer xen all SSE2 and SSE3 instructions are >> effectively working. >> I tried this simple program to test SSE2: >> http://forum.nasm.us/index.php?topic=1605.0 >> But probably use only instructions with short operand because SSE2 on this >> program is working also on old xen 4.0 where Jan Beulich patches to support >> long operands are missing. >> Are there any minimal program to test if SSE instructions with MMIO operands >>> 8 byte are working? > I don't see the code there doing MMIO -- it's just doing operations on > normal RAM, which is not emulated by Xen at all, but executed natively > by the processor. > > What you need is a program that will do this to an MMIO region -- that > will be a much trickier thing to set up, I think. > > -George The problem with SSE is only when the guest performs an SSE (or larger) operation on a piece of memory which ends up being emulated and handed to qemu. The ioreq protocol doesn't have a way of signalling an operand width greater than 64 bits. All operations on regular RAM should be fine, and should have no Xen interception. ~Andrew