The automatic port allocation algorithm for displays in libvirt seems to
assume that it is the only thing that will be allocating ports in the
normal VNC range starting at port 5900.
My host is running vino to export it's display, which has bound itself
to port 5900, yet libvirt is still trying to use port 5900 for both VNC
and Spice displays if I leave it in auto allocation mode.
I thought that this used to work in F14 but having just tried it again
it looks like I may have been mistaken.
Certainly it doesn't seem to work properly in F15 either with the
standard libvirt or with the virt-preview one.
Tom
--
Tom Hughes (tom(a)compton.nu)
http://compton.nu/