Yes. Then, I think that the MMU (Memory Management Unit) has a special case to multiprocessor in pmap.c. If It's correct, then we don't need to implement multiprocessor support in MMU (may we need to fix any error, of course).
So, to implement SMP, we have to add IPI support in process scheduler and isolate the drivers. Is It correct?
About drivers, I think that isolate Linux drivers are a good option, while the migration to userspace is in development. Once this migration will be ready, we will undo the isolation of this drivers.
Thanks, and excuse me the offtopic.