Yes, you still will create a 32 bit DWORD and it should be a "0" in decimal mode. You can verify if this is working with 3DMark 06. On our system here with a Quadro 4000 we have seen the FPS on the first test briefly reach 70 FPS in some scenes (mainly at the beginning) and finishing with a total of 4200 frames over the duration of the first test. As mentioned previously in this thread the other tests really don't run (errors are thrown) through the view client. Through the console the whole test suite will run, but it will not with the view client.
With regard to the P0 state. I do not believe there is a way currently to bind the GPU to always use max performance (P0 state) like you can in various Windows GPU utilities or even in some Linux distros. Accessing a GPU at the Hypervisor level is still new, so I'd imagine it may be a while if ever that there are any GPU utilities that will have this capability of GPU tuning that you are asking about unless it will be added to the nvidia-smi command line tool set in the future. Besides I do not believe that this action would really get you much of a performance increase (maybe a little). When there is GPU work it throttles up and if there is not it throttles down (to conserve power).