On Mon, Aug 04, 2014 at 04:47:11PM +0100, Alex Bligh wrote: > > On 4 Aug 2014, at 16:38, Serge Hallyn <serge.hallyn@xxxxxxxxxx> wrote: > > >> > >> If you really want it to be called pc-1.0, you > >> can make it a machine property instead. > >> E.g. qemu-kvm-compatibility. > >> Teach management to set it if remote is qemu-kvm: > >> -machine pc-1.0,qemu-kvm-compatibility=on > > > > That sounds nice - Alex, what do you think? > > Not having used the machine property stuff before, > or played with libvirt much, I'm not sure how this > helps libvirt. > > I thought the issue here was that migrating from > 1.0-qemu-kvm to 2.x OR 1.0-qemu-git to 2.x, libvirt > is going to to supply the same command line. > As > libvirt doesn't know what the sender is (and > it's not possible to detect this automatically - > at least not without a far more intrusive patch), Yes, this is up to higher level user. At libvirt xml level, you would just specify something like "legacy qemu-kvm compatibility" in the xml. > one has to make a choice at build time as to what > 'pc-1.0' represents. There's no choice really. Downstreams must make sure their machine types are distinct from upstream ones. qemu-kvm as a downstream violated this rule but I don't think this means upstream should violate it. > This is what patch #2 does. > I fully agree it is not pretty. The problem is not prettyness. The problem is, it creates a situation where two instances of qemu have different ideas about what a specific machine type is. > So I am not sure why > -machine pc-1.0,qemu-kvm-compatibility=on > is any easier for libvirt than > -machine pc-1.0-qemu-kvm > > IE what does using a machine property rather than > a machine type buy us? Seems to be easier to understand that it maps to pc-1.0 on the other side. > -- > Alex Bligh > > > -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list