[libvirt] device type 'interface' cannot be attached

[Gerry Reno]

I'm using libvirt 0.6.2 on F11 x86_64 and CPU supports hw 
virtualization.  When I try to do 'virsh attach-interface ...' I get an 
error that the function is not supported by the hypervisor device type 
'interface' cannot be attached.  Is this command not supported?  Or is 
there something special I need to do?  I found it in the man page.

-Gerry