On Fri, 19 Feb 2016 17:27:33 +0100 Greg Kurz <gk...@linux.vnet.ibm.com> wrote:
> On Fri, 19 Feb 2016 15:41:10 +0100 > Laurent Vivier <lviv...@redhat.com> wrote: > > > On 18/02/2016 12:32, 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. > > > > I've tested all possible combinations, with and without these patches. > > The result is here: > > > > http://wiki.qemu.org/Migration/Compatibility/pseries > > > > Excellent ! Thanks for setting this up. > > > - Migration is totally broken in qemu-2.2 > > Hmm... I get another error with qemu-2.2: > > htab_load() bad index -65536 (0+8454 entries) in htab stream (htab_shift=26) > qemu: warning: error while loading state section id 20 > qemu-system-ppc64: load of migration failed: Invalid argument > and this happens on my ppc64le host because QEMU 2.2 doesn't have: commit e094c4c12f33a1c965f5af02f33968a337348739 Author: Cédric Le Goater <c...@fr.ibm.com> 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. > > > - 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. > > > > Feel free to update the page. > > > > Laurent > > > >
