You should try connecting to the VM via VNC and see what's happening on that
side. The XML you pasted was for a VM not running, when it's running, you'll
see a port defined in <graphics type='vnc' port='-1'
autoport='yes'
listen='127.0.0.1'/>.
Did you enter those MAC addresses or did you let libvirt generate them for
you?
.:. jeremy