Edit Video driver used and Video memory

Hi guys,

Wondering if anyone could help with this please, I am trying to add more video memory to my guest machines (E.g. for running a Desktop version of the operating system).

it seems by default it uses the followowing:

virsh dumpxml 377

Ideally i want it to use 32mb of RAM and a better drive (qxldriver for example).
is there any way i can do so in opennebula as if I edit the XML directly it messes the VM up.

I would like to see if the graphics do benifit from the additional video memory as it seems when i create desktop versions no matter how much ram I throw at it or CPU its always a bit sluggish.
i have tried Spice also and get the same results.

Any help on this would be appreciated or any other known tweaks for sorting graphics out.