I don't know all the ins and outs of checkpointing, but it looks ok to me. You aren't serializing all the state in the Interrupts object, but the things you left out I think are set up from configuration parameters directly or indirectly. Someone else will have to say whether that's ok, but I suspect it is.

I don't know about the interrupt device, the but TLB code is good - recently duplicated this myself :(.  Not that it was a lot of work, but still :(.