https://bugs.freedesktop.org/show_bug.cgi?id=45018
--- Comment #41 from Alex Deucher agd5f@yahoo.com 2012-03-20 12:11:26 PDT --- Are you still getting any messages like the following in your dmesg with the latest mesa from git?
radeon 0000:01:00.0: offset 0x200000 is in reserved area 0x800000 radeon 0000:01:00.0: offset 0x200000 is in reserved area 0x800000
I pushed a patch yesterday that fixed up a missing va setup, although I don't think the driver should hit that path with cayman and vm support.