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 - Migration is totally broken in qemu-2.2 - 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
