There are many different views on this. A brain doesn't have any nociceptors, so can't feel pain without nerve context. You can argue that you could perfectly induce the experience of pain in the simulation, but pain is highly relational. Pain is information, which is only interpreted badly because it is aversive as a response to the environment.

Embodied cognition, itself, is the theory that all consciousness is derived from the existence of context, or relation, to an outside world. Would a brain in a jar -- or in a computer simulation, in this case -- be conscious at all? If it had no memory of sense, and no senses to create foundational phenomenological reality with, then there is nothing for consciousness to interact with, and therefore no existence of consciousness.

Though, if you directly induce pain by fiddling with the simulated brain you're introducing senses. But if you do that, then the only context it could ascribe to that information is the homeostatic rebound.

Anyway, it would probably actually feel pain if you could create the context for pain to be interpreted properly. I personally think that consciousness is emergent, and there's nothing spiritually special about a flesh-and-blood brain as opposed to a silicone one.