0x00: i440fx
0x01: PIIX3 (and related - ide, ...)
0x02: graphic card (if present)

+1 Than by default NIC (we set different ADDR so doesn't apply)
+1 soundcards (when using -device we can set different address, but when using -soundhw all uses first free addresses so 0x03, 0x04, 0x05. When -device is not supported, we assume that every card is PCI so get addr per each soundcard)
+1 autocreated scsi HBA
...