My comment may not apply to this, but I'll make it anyhow:
I upgraded my host server from ubuntu 12.04 to 14.04. Afterwards, none of my desktop VM's worked (I haven't even tried the server VM's yet). I made a new guest VM using the exact same "virst-install" command I had used for the original VM creation on the 12.04 host server, and compared the resulting .xml file. There were 3 or 4 differences, but this one:
I used "virsh edit" and changed that line and the guest VM originally created under a 12.04 server host then worked under the 14.04 server host.
Note: So far, this change has been made to 6 VM's (5 are either 14.04 originally or as upgraded from 13.10, and one was a 12.04 Desktop guest VM) and 5 of them are now working. The one is only not working for one log in type out of 5 possible (GNOME; GNOME Classic; GNOME Flashback (Compiz); GNOME Flashback (Metacity); Ubuntu (Default)).
My comment may not apply to this, but I'll make it anyhow:
I upgraded my host server from ubuntu 12.04 to 14.04. Afterwards, none of my desktop VM's worked (I haven't even tried the server VM's yet). I made a new guest VM using the exact same "virst-install" command I had used for the original VM creation on the 12.04 host server, and compared the resulting .xml file. There were 3 or 4 differences, but this one:
<type arch='x86_64' machine= 'pc-1.0' >hvm</type>
in 14.04 became this:
<type arch='x86_64' machine= 'pc-i440fx- 1.7'>hvm< /type>
I used "virsh edit" and changed that line and the guest VM originally created under a 12.04 server host then worked under the 14.04 server host.
Note: So far, this change has been made to 6 VM's (5 are either 14.04 originally or as upgraded from 13.10, and one was a 12.04 Desktop guest VM) and 5 of them are now working. The one is only not working for one log in type out of 5 possible (GNOME; GNOME Classic; GNOME Flashback (Compiz); GNOME Flashback (Metacity); Ubuntu (Default)).