Comment 4 for bug 962376

I had a similar problem (spicevmc not supported) but when trying to start the guest from libvirt. The cause was the libvirt .XML file where it specified the emulator to always be the non-spice executable, ie:

<emulator>/usr/bin/kvm</emulator>

Remove this line completely, or change it to:

<emulator>/usr/bin/kvm-spice</emulator>

That allowed to me use the spice protocol, although I get a blank black screen when using any video driver other than cirrus. :(