From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: [PATCH] libxl: Remove qxl support for the 4.3 release Date: Tue, 28 May 2013 19:09:03 +0100 Message-ID: References: <20900.57461.535517.705987@mariner.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20900.57461.535517.705987@mariner.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Jackson , George Dunlap Cc: Fabio Fantoni , Ian Campbell , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org 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. -- Keir > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel