"ding ding ding In this corner.. "
Cliched. And I've used it a number of times. But this actually caused me a lot of paralyzed excitement last night.
I took a VM I created as a Xen guest, one I've been using for years, and copied it over to a KVM host. And it ran.
No modifcations. No goofy xen kernel options. A plain jane vanilla install of F18, selecting the "infrastructure / virtualization" option, ran the updates, then copied over the VM and used the virt-manager to import the existing Xen VM image and it just runs.
mind=blown
brb switching to KVM.