Hi, to migrate your Xen instances to KVM you have to add some virtio kernel modules to the VMs image. Within the VM you can find the modules by running find /lib/modules/ -name *virtio*, add them all or just a few to the initrd (if dracut is installed): dracut --add-drivers "virtio virtio_scsi.ko <AND_SO_ON>" --force. This did the trick for us. You would have to upload the instances again, of course. Hope this helps!