- missing hotplug for disks
- daemon restart kills VMs
- missing migration support
Since KVM now supports PCI hotadd since a couple of releases I fixed up 1 today. I already sent a partial patch for 2 some time ago which I need to finish and clean up. Hopefully 3 is resolved upstream until then.
Once this is done libvirt plus kvm will be a great tandem for virtualization. On the desktop virt-manager does a great job while for H/A purposes it integrates with Redhat's cluster suite - you can use the vm.sh resource script for this after removing the xen specific code and replacing it with calls to ''virsh''.