qemu-kvm w2k3 virtio disk drivers

1.) Download the disk-virtio ISO and copy the content into the guest's partition.
2.) Start VM and attach a disk:
virsh attach-disk w2k3 /mnt/bgerofi-virtual_machines/winxp/winxp.raw vdb --type disk --type file
3.) Specify the disk-virtio driver for the new SCSI device.
4.) Shutdown, undefine VM, modify xml and redifine VM so that disk is virtio.