From xen-devel-bounces@lists.xen.org Mon Sep 16 15:31:31 2013 Received: (at maildrop) by bugs.xenproject.org; 16 Sep 2013 14:31:31 +0000 Received: from lists.xen.org ([50.57.142.19]) by bugs.xenproject.org with esmtp (Exim 4.80) (envelope-from ) id 1VLZpr-0004mo-IU for xen-devel-maildrop-Eithu9ie@bugs.xenproject.org; Mon, 16 Sep 2013 15:31:31 +0100 Received: from localhost ([127.0.0.1] helo=lists.xen.org) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VLZnA-0003rf-Rw; Mon, 16 Sep 2013 14:28:44 +0000 Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1VLZn7-0003rY-Q8 for xen-devel@lists.xen.org; Mon, 16 Sep 2013 14:28:43 +0000 Received: from [85.158.139.211:5028] by server-8.bemta-5.messagelabs.com id 84/AC-17437-99517325; Mon, 16 Sep 2013 14:28:41 +0000 X-Env-Sender: JBeulich@suse.com X-Msg-Ref: server-13.tower-206.messagelabs.com!1379341720!2715200!1 X-Originating-IP: [130.57.49.28] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogMTMwLjU3LjQ5LjI4ID0+IDQ4MDU=\n X-StarScan-Received: X-StarScan-Version: 6.9.12; banners=-,-,- X-VirusChecked: Checked Received: (qmail 16296 invoked from network); 16 Sep 2013 14:28:40 -0000 Received: from nat28.tlf.novell.com (HELO nat28.tlf.novell.com) (130.57.49.28) by server-13.tower-206.messagelabs.com with DHE-RSA-AES256-SHA encrypted SMTP; 16 Sep 2013 14:28:40 -0000 Received: from EMEA1-MTA by nat28.tlf.novell.com with Novell_GroupWise; Mon, 16 Sep 2013 15:28:39 +0100 Message-Id: <523731B302000078000F3B25@nat28.tlf.novell.com> X-Mailer: Novell GroupWise Internet Agent 12.0.2 Date: Mon, 16 Sep 2013 15:28:35 +0100 From: "Jan Beulich" To: "George Dunlap" , "Fabio Fantoni" References: <1369813427.22605.38.camel@dagon.hellion.org.uk> <51A68060.7010500@citrix.com> <5237114A.9050201@m2r.biz> In-Reply-To: <5237114A.9050201@m2r.biz> Mime-Version: 1.0 Content-Disposition: inline Cc: Andrew Cooper , Keir Fraser , "xen-devel@lists.xen.org" Subject: Re: [Xen-devel] [PATCH] libxl: Remove qxl support for the 4.3 release X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org >>> On 16.09.13 at 16:10, Fabio Fantoni wrote: > Il 05/07/2013 18:59, George Dunlap ha scritto: >> On Wed, May 29, 2013 at 11:25 PM, Andrew Cooper >> wrote: >>> On 29/05/2013 08:43, Ian Campbell wrote: >>>> On Tue, 2013-05-28 at 19:09 +0100, Keir Fraser wrote: >>>>> On 28/05/2013 17:51, "Ian Jackson" wrote: >>>>> >>>>>> George Dunlap writes ("[PATCH] libxl: Remove qxl support for the 4.3 >>>>>> release"): >>>>>>> The qxl drivers for Windows and Linux end up calling instructions >>>>>>> that cannot be used for MMIO at the moment. Just for the 4.3 release, >>>>>>> remove qxl support. >>>>>>> >>>>>>> This patch should be reverted as soon as the 4.4 development window opens. >>>>>>> >>>>>>> The issue in question: >>>>>>> >>>>>>> (XEN) emulate.c:88:d18 bad mmio size 16 >>>>>>> (XEN) io.c:201:d18 MMIO emulation failed @ 0033:7fd2de390430: f3 0f 6f >>>>>>> 19 41 83 e8 403 >>>>>>> >>>>>>> The instruction in question is "movdqu (%rcx),%xmm3". Xen knows how >>>>>>> to emulate it, but unfortunately %xmm3 is 16 bytes long, and the interface >>>>>>> between Xen and qemu at the moment would appear to only allow MMIO accesses >>>>>>> of 8 bytes. >>>>>>> >>>>>>> It's too late in the release cycle to find a fix or a workaround. >>>>>> Acked-by: Ian Jackson >>>>> It could be plumbed through hvmemul_do_io's multi-cycle read/write logic, >>>>> and done as two 8-byte cycles to qemu. This would avoid bloating the ioreq >>>>> structure that communicates to qemu. >>>> Are you proposing we do this for 4.3? I'm not sure how big that change >>>> would be in terms of impact (just that one instruction, any 16 byte >>>> operand?). >>>> >>>> Of course even if we did this for 4.3 we don't know what the next issue >>>> will be with QXL. >>>> >>>> Ian. >>> Furthermore, AVX instruction emulation would require support for 32byte >>> operands. I don't see the multi-cycle logic scaling sensibly. >> Andrew, Keir, Jan, does any one of you fancy taking this on for 4.4? > > Is there someone that can add full support for SSE on hvm domUs? > Thanks for any reply. I was intending to take a look whether this can be done without altering the interface with qemu, in which case I may be able to get this implemented. But as long as higher priority work keeps showing up, this will continue to get deferred... Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel