From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52971) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZFyK-0007tF-KR for qemu-devel@nongnu.org; Fri, 26 Feb 2016 05:50:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aZFyG-0001lI-KR for qemu-devel@nongnu.org; Fri, 26 Feb 2016 05:50:08 -0500 Received: from e06smtp15.uk.ibm.com ([195.75.94.111]:57198) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aZFyG-0001l6-BQ for qemu-devel@nongnu.org; Fri, 26 Feb 2016 05:50:04 -0500 Received: from localhost by e06smtp15.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 26 Feb 2016 10:50:02 -0000 Date: Fri, 26 Feb 2016 11:49:56 +0100 From: Greg Kurz Message-ID: <20160226114956.7e08af4d@bahia.huguette.org> In-Reply-To: <20160222010912.GB2808@voom.fritz.box> References: <20160218113211.9760.85475.stgit@bahia.huguette.org> <20160219001147.GN15224@voom.fritz.box> <20160219085944.281f4a73@bahia.huguette.org> <20160222010912.GB2808@voom.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/2] Fix migration of old pseries List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: Laurent Vivier , Juan Quintela , qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , qemu-ppc@nongnu.org, Amit Shah On Mon, 22 Feb 2016 12:09:12 +1100 David Gibson wrote: > On Fri, Feb 19, 2016 at 08:59:44AM +0100, Greg Kurz wrote: > > On Fri, 19 Feb 2016 11:11:47 +1100 > > David Gibson wrote: > > > > > On Thu, Feb 18, 2016 at 12:32:11PM +0100, Greg Kurz wrote: > > > > QEMU 2.4 broke the migration of old pseries machine with the addition > > > > of configuration sections, which are sent unconditionally. > > > > > > > > We assume that QEMU 2.3 is more deployed than any newer release (based on > > > > the versions currently shipped by most distros). This v3 series hence > > > > reverses the logic from v2: it now fully fixes migration of old pseries > > > > from/to QEMU 2.3 and provides a manual workaround for the QEMU 2.4/2.4.1/2.5 > > > > case. > > > > > > > > With this series, I could migrate the same pseries-2.3 instance in a full > > > > 2.3->2.6->2.5->2.6->2.4->2.6->2.3 cycle. > > > > > > Sorry, I've lost track slightly here. Does this series apply on top > > > of, or instead of your earlier series that peeks for the config > > > section? > > > > > > > This v3 series applies instead of the v2 that peeks for the config section. > > Ok, thanks for the clarification. > > > It was suggested by Laurent during review, and motivated by your decision > > to favor fixing 2.3 over 2.4. > > > > As shown in Laurent's detailed test report, migration from/to 2.3.x now works > > out of the box and 2.4.x/2.5 requires qom-set. > > > > I was also feeling a bit uncomfortable with all these machine properties to > > disable the configuration section, which was explicitly coded to be non-optional > > according to the changelog of commit 61964c23. The logic inversion in v3 seem > > to be friendlier with the configuration section design. > > > > Juan, could you share your thoughts ? > > With an ack from Juan I'll be happy to merge this to ppc-for-2.6. > And the patches even got reviewed by Juan ! Please merge ! :)