Re: [Qemu-devel] [libvirt] [PATCH v3 2/2] Add configure option --enable-pc-1-0-qemu-kvm

[Paolo Bonzini <pbonzini@redhat.com>]

Il 22/09/2014 17:24, Markus Armbruster ha scritto:
> You're right.  However, this particular horse left the barn a long time
> ago: the pc-* machine types differ in qemu-kvm and upstream QEMU.
> 
> Sure, when qemu-kvm was merged back into QEMU, its machine type variants
> were dropped.  But they live on in various downstreams that just like
> QEMU had to pick between compatibility with upstream QEMU and qemu-kvm,
> but unlike QEMU picked compatibility with qemu-kvm.

And fixing this should have been downstream's job.  Fedora did it at the
time, RHEL7 did it.  Ubuntu didn't, and probably neither did Debian.

This patch singles out pc-1.0 just because it used to be the default in
Ubuntu 12.04.  So basically it's making upstream carry the burden of a
decision of the Ubuntu folks.  It's understandable that Alex disagrees
with the decision, but nevertheless it's not something that upstream
should agree with.

Also, another horse that has left the barn: it's already too late to
apply this patch to upstream Ubuntu.  If you do that, any machine
created with 12.04 and reused with 14.04 will fail to migrate to another
14.04 machine that includes this patch, as I understand it.

So as things stand, I don't see a reason to apply this patch upstream.

Paolo