I migrated my mail-server KVM and built a couple others since F17. No major problems. A little glitchiness wrt SELinux. I'm using libvirtd/virt-manager.
When you say ...
Does "It" refer to the kvm tool or to the guest ?
I *think* that trap & 'cnopen' message is from the BSD guest, but it's unclear.
Are you using libvirtd & virt-manager or are you rolling your own qemu-kvm command ?
Can you post the full command ?
I *suspect* you have configured the guest w/ no console device (maybe due to a kvm command parameter change).
Have you checked all the command parameters (there are a few changes to the command) ?
IMO running strace will be completely useless - waste of time.
The F17 changes to the executable and library layout has ZERO to do with this.