Comment 1 for bug 517478

virsh;
$ virsh -c qemu+ssh://<email address hidden>/system
error: server closed connection
error: failed to connect to the hypervisor

virt-manager:
Unable to open connection to hypervisor URI 'qemu+ssh://<email address hidden>/system':
server closed connection
Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/connection.py", line 896, in _try_open
    None], flags)
  File "/usr/lib/python2.6/dist-packages/libvirt.py", line 111, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: server closed connection

Maybe you need to install ssh-askpass in order to authenticate.