From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=53085 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PSMkD-0005yF-5D for qemu-devel@nongnu.org; Mon, 13 Dec 2010 23:44:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PSMkC-0006LT-9q for qemu-devel@nongnu.org; Mon, 13 Dec 2010 23:44:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:14798) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PSMkC-0006LC-2E for qemu-devel@nongnu.org; Mon, 13 Dec 2010 23:44:08 -0500 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oBE4i62u029518 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 13 Dec 2010 23:44:06 -0500 Date: Tue, 14 Dec 2010 06:43:43 +0200 From: "Michael S. Tsirkin" Message-ID: <20101214044342.GE9554@redhat.com> References: <1292171345.2857.43.camel@x201> <1292262202.2857.114.camel@x201> <20101213175010.GD7182@redhat.com> <1292263244.2857.120.camel@x201> <20101213185437.GB9554@redhat.com> <1292266756.2857.122.camel@x201> <20101213190619.GD9554@redhat.com> <1292267708.2857.123.camel@x201> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1292267708.2857.123.camel@x201> Subject: [Qemu-devel] Re: [PATCH] rtl8139: IO memory is not part of vmstate List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alex Williamson Cc: qemu-devel@nongnu.org, quintela@redhat.com On Mon, Dec 13, 2010 at 12:15:08PM -0700, Alex Williamson wrote: > On Mon, 2010-12-13 at 21:06 +0200, Michael S. Tsirkin wrote: > > On Mon, Dec 13, 2010 at 11:59:16AM -0700, Alex Williamson wrote: > > > On Mon, 2010-12-13 at 20:54 +0200, Michael S. Tsirkin wrote: > > > > On Mon, Dec 13, 2010 at 11:00:44AM -0700, Alex Williamson wrote: > > > > > On Mon, 2010-12-13 at 19:50 +0200, Michael S. Tsirkin wrote: > > > > > > On Mon, Dec 13, 2010 at 10:43:22AM -0700, Alex Williamson wrote: > > > > > > > So, unfortunately, I stand by my original patch. > > > > > > > > > > > > What about the one that put -1 in saved index for a hotplugged device? > > > > > > > > > > There are still examples that don't work even without hotplug (example 2 > > > > > and example 3 after the reboot). That hack limits the damage, but still > > > > > leaves a latent bug for reboot and doesn't address the non-hotplug > > > > > scenarios. So, I don't think it's worthwhile to pursue, and we > > > > > shouldn't pretend we can use it to avoid bumping the version_id. > > > > > Thanks, > > > > > > > > > > Alex > > > > > > > > I guess when we bump it we tell users: migration is completely > > > > borken to the old version, don't even try it. > > > > > > > > Is there a way for libvirt to discover such incompatibilities > > > > and avoid the migration? > > > > > > I don't know if libvirt has a way to query this in advance. If a > > > migration is attempted, the target will report: > > > > > > savevm: unsupported version 5 for '0000:00:03.0/rtl8139' v4 > > > > > > And the source will continue running. We waste plenty of bits getting > > > to that point, > > > > Yes, this happens after all of memory has been migrated. > > Better late than never :^\ One other question: can we do the same by creating a new (empty) section? As was discussed in the past this is easier for downstreams to cherry-pick. -- MST