The interrupts are inputs TO microblaze? As in there is an external interrupt source and microblaze is the sink for 9 seperate interrupts?
You could of course do the following:
You wire-or the 9 interrupt inputs, the result of which is a single interrupt line going into microblaze. And you conveniently also read in the 9 lines as GPIO. So you have 1 interrupt input, and then 9 regular boring inputs for priority decoding. And if you feel like it you can do the priority decoding before you send it to microblaze, which would get you a 4-bit priority.