This is my first try to use KVM (have been using VirtualBox for years) and everything was pretty easy to do except getting the VM to display on more than one monitor (I have 2). Both my host and guest are Ubuntu GNOME 16.04.1.
Per various doc, posts etc I have
> Set Display to Type:Spice server
> Set Video to Model: QXL (under which it says "Heads: 1"
I tried adding a second QXL device but when I booted the VM I only got a terminal, no desktop GUI.
An additional note: On the guest, in Display Settings there is only one display.