Fuzzing of bhyve uncovered an assertion failure in the NVMe emulation.
Investigation uncovered several corner cases the code did not handle.
This change handles several Controller initialization errors, including
- bad AQ sizes
- bad AQ vm_map_gpa
- doorbell writes prior to RDY
- doorbell writes to uninitialized queue
- CSTS.RDY if CFS set
PR: 256317,256319,256320,256322
Reported by: Cheolwoo Myung <cwmyung@snu.ac.kr>