Hi,
For (2), you cannot use bus=X,addr=Y because it makes assumptions about the PCI topology which may change in newer -M pc's.
Why should the PCI topology for 'pc' ever change?We'll probably get q35 support some day, but when this lands I expect we'll see a new machine type 'q35', so '-m q35' will pick the ich9 chipset (which will have a different pci topology of course) and '-m pc' will pick the existing piix chipset (which will continue to look like it looks today).
cheers, Gerd
