https://bugzilla.kernel.org/show_bug.cgi?id=66281
--- Comment #3 from Ilia Mirkin imirkin@alum.mit.edu --- Make sure that
(a) You're using a kernel 3.14 or higher (3.13 introduced modesetting but not the firmware required for acceleration for the gk208) (b) You're not using bumblebee (3.12 introduced runtime pm support for nouveau) (c) You have runtime pm and vga switcheroo enabled in your kernel (d) You're using xf86-video-nouveau 1.0.10 (first version to add gk208 support)
If you want 3d accel to be anywhere near working, I would also recommend grabbing mesa 10.2-rc1 as that has a number of instruction emission fixes, although simple programs like glxgears are likely to work on older mesa versions as well.
Lastly, as per http://nouveau.freedesktop.org/wiki/Bugs/, you will find the fdo bugtracker a much more reliable way to reach nouveau developers.