From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41526) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W8UtR-0003dB-U3 for qemu-devel@nongnu.org; Wed, 29 Jan 2014 08:09:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W8UtL-00079o-V8 for qemu-devel@nongnu.org; Wed, 29 Jan 2014 08:09:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2327) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W8UtL-00079a-M0 for qemu-devel@nongnu.org; Wed, 29 Jan 2014 08:09:19 -0500 Message-ID: <52E8FD39.8030307@redhat.com> Date: Wed, 29 Jan 2014 14:08:09 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [BUG] BSoD on Windows XP installation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefano Stabellini Cc: Anthony Perard , George Dunlap , xen-devel@lists.xensource.com, qemu-devel@nongnu.org Il 29/01/2014 13:00, Stefano Stabellini ha scritto: > Hi Paolo, > we have been trying to fix a BSOD that would happen during the Windows > XP installation, once every ten times on average. > After many days of bisection, we found out that commit > > commit 149f54b53b7666a3facd45e86eece60ce7d3b114 > Author: Paolo Bonzini > Date: Fri May 24 12:59:37 2013 +0200 > > memory: add address_space_translate > > breaks Xen support in QEMU, in particular the Xen mapcache. > The reason is that after this commit, l in address_space_rw can span a > page boundary, however qemu_get_ram_ptr still calls xen_map_cache asking > to map a single page (if block->offset == 0). > The appended patch works around the issue by reverting to the old > behaviour. > > What do you think is the right fix for this? > Maybe we need to add a size parameter to qemu_get_ram_ptr? Yeah, that would be best but the patch you attached is fine too with a FIXME comment. Paolo > I should add that this problem is time sensitive because is a blocker > for the Xen 4.4 release (Xen is in RC2 right now). > > Thanks for your feedback, From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [BUG] BSoD on Windows XP installation Date: Wed, 29 Jan 2014 14:08:09 +0100 Message-ID: <52E8FD39.8030307@redhat.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-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org To: Stefano Stabellini Cc: Anthony Perard , George Dunlap , xen-devel@lists.xensource.com, qemu-devel@nongnu.org List-Id: xen-devel@lists.xenproject.org Il 29/01/2014 13:00, Stefano Stabellini ha scritto: > Hi Paolo, > we have been trying to fix a BSOD that would happen during the Windows > XP installation, once every ten times on average. > After many days of bisection, we found out that commit > > commit 149f54b53b7666a3facd45e86eece60ce7d3b114 > Author: Paolo Bonzini > Date: Fri May 24 12:59:37 2013 +0200 > > memory: add address_space_translate > > breaks Xen support in QEMU, in particular the Xen mapcache. > The reason is that after this commit, l in address_space_rw can span a > page boundary, however qemu_get_ram_ptr still calls xen_map_cache asking > to map a single page (if block->offset == 0). > The appended patch works around the issue by reverting to the old > behaviour. > > What do you think is the right fix for this? > Maybe we need to add a size parameter to qemu_get_ram_ptr? Yeah, that would be best but the patch you attached is fine too with a FIXME comment. Paolo > I should add that this problem is time sensitive because is a blocker > for the Xen 4.4 release (Xen is in RC2 right now). > > Thanks for your feedback,