The local spice renderer assumes the primary surface is located at the
start of the "ram" bar. This used to be a requirement in qxl hardware
revision 1. In revision 2+ this is relaxed. Nevertheless guest drivers
continued to use the traditional location, for historical and backward
compatibility reasons. The qxl kms driver doesn't though as it depends
on qxl revision 4+ anyway.
Result is that local rendering is hosed for recent linux guests, you'll
get pixel garbage with non-spice ui (gtk, sdl, vnc) and when doing
screendumps. Fix that by doing a proper mapping of the guest-specified
memory location.
https://bugzilla.redhat.com/show_bug.cgi?id=948717
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
