I'm not sure, that's the point :-)
I know there are soft interrupts that can be triggered, eg calling CausePPCInterrupt() (or whatever it's called) from the 68K etc, as a fast way of getting the PPC to do something (no cache arbitrartion is performed).
I need to find out if I can get the PPC under warpos to respond to a CIA level interrupt, preferably without a lot of context switches (without any, preferably).