In VirtualBox without the extensions, I believe we will currently fall back to either VESA or EFI GOP modesetting, neither of which indeed have KMS support yet.

In VirtualBox without the extensions, I believe we will currently fall back to either VESA or EFI GOP modesetting, neither of which indeed have KMS support yet. There was a patchset to support KMS for simple fb fallbacks, but it hasn't been merged yet. http://cgit.freedesktop.org/~dvdhrm/linux/log/?h=simpledrm http://cgit.freedesktop.org/~dvdhrm/linux/log/?h=simpledrm However, I definitely wouldn't throw out KMS just to support VESA / GOP. They don't support page flipping, so you get lots of tearing. With the extensions, vboxdrv supplies a KMS driver. https://www.virtualbox.org/svn/vbox/trunk/src/VBox/Additions/linux/drm/vboxvideo_drm.c https://www.virtualbox.org/svn/vbox/trunk/src/VBox/Additions...