I suspect that it will not. I am hoping to unblock our use on NVidia and then to get in touch with some of the gfx team to hear more about the details of how they think we should architect this (I've been unable to figure out their plans from some casual IRC conversations or the source/wiki pages, though I'm pretty new to this space). They did tell me that if you share an X pixmap, it's tied to the X display connection it was created on, so I suspect we would either need to `dup()` the X display socket or be sharing something else.