So as part of my quick hacks work I got an accelerated X server on intel hw that ran as a user today.
The hacked up patches were around 300 lines total, one bit in the xserver, lots of non-root ioctl hacks to the drm and the intel driver had to register it wasn't a hw driver with X, and then fix up its buffer allocations to be non-evicted.
Surprisingly it mostly seems to work, I can start the server + gnome-session + DRI2 + compiz + glxgears on a cube, granted it oopses soon afterwards but it does show we are very close to realising the dream.
The xserver patch is in master, the drm patches are in modesetting-101 and the intel hacks are in the intel-kernelmode branch of my personal repo, as they are very hacky.
Lots of things need to be fixed so this can be done properly but it nice to just see what it looked like e.g. the frontbuffer isn't pinned properly or the cursors etc.
I have to log in on the console on vt2 and then run the following.
/opt/xorg/bin/Xorg -logfile ~/xorglog -sharevts -novtswitch vt02
Granted I'm not sure how reproducible this is, it was afternoon hacks to get over the F9 bugfixing :)