On Wed, Jul 28, 2010 at 18:43, Juan Quintela <quint...@redhat.com> wrote: > TeLeMan <gele...@gmail.com> wrote: >> If the new version adds the new subsection for some vmstate, the old >> version will load the new version's vmstate unsuccessfully. So we have >> to ignore the unrecognized subsections. > > No. That was the whole point of subsections. If one subsection is > sent, target machine has to understand it. If it don't understand it, > it fails. > > If subsection is not needed, it is the responsability of the source to > not send it. > > This was one of the design requirements. Subsections are optional but > it is the source which decides which ones to send/not to send. The > target has to understand everything that it gets or fail the migration. >
If the target must understand everything, the vmstate's version will be useless because the old version target maybe cannot load the new version target's vmstate.
