On Mon, 22 Feb 2016 12:09:12 +1100 David Gibson <da...@gibson.dropbear.id.au> 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 <da...@gibson.dropbear.id.au> 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 ! :)
