If we get to the point where minds can simulate other minds

Human minds (given the biological constraints) are unlikely to be able to simulate other human minds to the extent that we need to start worrying about the rights of the simulated mind. In cases where something similar happens (split personality, tulpas) I haven't seen serious ethical concerns raised, partially, I think, because it's all still you. People can and do torture themselves by their thoughts but suggesting to forbid it is... silly.

Now, if we are talking about enhanced cyborg brains or uploads (ems) running on powerful hardware, well, maybe it could become a problem at that point. Until then I don't see how this is an issue.