According to one of the VirtualBox developers (Frank Mehnert), bugs
621893 (VirtualBox) and 623956 (KVM) may actually be the same bug in
Xorg affecting VESA 2.0. He filed an upstream bug
https://bugs.freedesktop.org/show_bug.cgi?id=30585
which was closed as a duplicate of
https://bugs.freedesktop.org/show_bug.cgi?id=30159
which was originally filed on 9-13 and for which Adam Jackson already
has a proposed patch. It's possible that other basic video bugs such as
627073, 632805, and 633247 affecting bare metal might be the same. Is it
possible to get a fix for this by Final TC1?