From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44500) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYEVm-0001dT-MX for qemu-devel@nongnu.org; Tue, 23 Feb 2016 10:04:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aYEVi-00043q-Co for qemu-devel@nongnu.org; Tue, 23 Feb 2016 10:04:26 -0500 Received: from e06smtp05.uk.ibm.com ([195.75.94.101]:46369) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aYEVi-00043c-3Y for qemu-devel@nongnu.org; Tue, 23 Feb 2016 10:04:22 -0500 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 23 Feb 2016 15:04:20 -0000 Date: Tue, 23 Feb 2016 16:04:13 +0100 From: Greg Kurz Message-ID: <20160223160413.6d295ad3@bahia.huguette.org> In-Reply-To: <20160219172733.05882b0d@bahia.huguette.org> References: <20160218113211.9760.85475.stgit@bahia.huguette.org> <56C72986.2030205@redhat.com> <20160219172733.05882b0d@bahia.huguette.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v3 0/2] Fix migration of old pseries List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laurent Vivier Cc: Juan Quintela , qemu-devel@nongnu.org, "Dr. David Alan Gilbert" , qemu-ppc@nongnu.org, Amit Shah , David Gibson On Fri, 19 Feb 2016 17:27:33 +0100 Greg Kurz wrote: > On Fri, 19 Feb 2016 15:41:10 +0100 > Laurent Vivier wrote: >=20 > > On 18/02/2016 12:32, Greg Kurz wrote: =20 > > > QEMU 2.4 broke the migration of old pseries machine with the addition > > > of configuration sections, which are sent unconditionally. > > >=20 > > > We assume that QEMU 2.3 is more deployed than any newer release (base= d on > > > the versions currently shipped by most distros). This v3 series hence > > > reverses the logic from v2: it now fully fixes migration of old pseri= es > > > from/to QEMU 2.3 and provides a manual workaround for the QEMU 2.4/2.= 4.1/2.5 > > > case. > > >=20 > > > 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. =20 > >=20 > > I've tested all possible combinations, with and without these patches. > > The result is here: > >=20 > > http://wiki.qemu.org/Migration/Compatibility/pseries > > =20 >=20 > Excellent ! Thanks for setting this up. >=20 > > - Migration is totally broken in qemu-2.2 =20 >=20 > Hmm... I get another error with qemu-2.2: >=20 > htab_load() bad index -65536 (0+8454 entries) in htab stream (htab_shift= =3D26) > qemu: warning: error while loading state section id 20 > qemu-system-ppc64: load of migration failed: Invalid argument >=20 and this happens on my ppc64le host because QEMU 2.2 doesn't have: commit e094c4c12f33a1c965f5af02f33968a337348739 Author: C=C3=A9dric Le Goater Date: Mon Nov 3 16:14:50 2014 +0100 target-ppc: explicitly save page table headers in big endian > but my command line is different from yours. >=20 > > - without these patches, migration cannot be done from/to qemu-2.3 > > - with these patches, qemu-2.3 can migrate to/from qemu-2.6 > > - 1st patch breaks pseries-2.2, pseries-2.3 migration from/to > > qemu-2.4/2.5 but 2nd patch allows to fix this manually. > >=20 > > Feel free to update the page. > >=20 > > Laurent > > =20 >=20 >=20