This is only lightly tested at the moment.
For context see:
https://bugzilla.redhat.com/show_bug.cgi?id=1138203#c40
https://bugzilla.redhat.com/show_bug.cgi?id=1075143
https://bugzilla.redhat.com/show_bug.cgi?id=1075164
Note this is not a complete fix. At least one more libguestfs patch
is required (to implement virDomainPtr in the python bindings). Plus
a virt-manager patch.
Rich.