On Tue, Nov 24, 2009 at 03:20:47PM +0100, Juan Quintela wrote: > "Michael S. Tsirkin" <m...@redhat.com> wrote: > > >> But to really make it work, we need to take a list of each savevm format > >> change and put it here. Notice that several changes are needed: > >> - savevm infrastructure save functions don't know about version id > >> - devices don't know to "behave" as other version > >> - other things that I have probably missed > >> > >> Later, Juan. > > > > Why do you think this the right place for it, I wonder? > > This describes the machine, it does not seem to have > > anything to do with how we migrate it. > > Becase here is where we know that _this_ machine had _this_ versions of > each device.
So? migration format is not related to what devices you have at all. It's how you save them. > And this is also the trivial part to describe: I want a > machine like the one in qemu-0.11. Yes, but there might be a ton of reasons to want a machine like the one in qemu 0.11. The need to migrate to old qemu is very rare, it is a completely separate decision one might take long after starting qemu, > What is more, it makes trivial for downstream to do things like: > - I define my machine, called foo-7.0, and the changes that it has over > any other machine. > > Later, Juan. Yes, machine desacription is a good thing. No, using it for things that have nothing to do with describing the machine is not a good thing. -- MST
