[libvirt] [PATCH]: Implement Qemu/KVM live migration

All, Attached is a patch to implement Qemu/KVM live migration in libvirt. Now that upstream Qemu has settled on an interface that is friendly to libvirt (i.e. one that doesn't block the monitor on -incoming), we can implement it here. Note that the bulk of this patch was written by Rich Jones quite a while ago. My hand in it has mostly been to forward port it to current libvirt CVS, tweak it for the new Qemu style, and test it out with a recent KVM (kvm-78, in particular). Note that there is a FIXME in the code. When testing this out with kvm-78, I found that if I let the source side kill the source VM immediately after the "migrate" monitor command completed, the migration to the destination would never complete. This seems to be a bug in Qemu; the migrate monitor command shouldn't return until the migrate is really, truly complete. I'm posting this now so I can get reviews, and start to address review comments while I try to figure out what's going on with Qemu. With my temporary hack of the sleep() call in there, though, I was able to successfully live migrate an F-9 guest between two machines. Signed-off-by: Chris Lalancette <clalance(a)redhat.com&gt;