Re: PCIe MSI-X interrupts

One thing to note::
The PCIe root complex may send out an address, but when the
MMI/O receiver of said address then uses bits in the address
for routing purposes or interpretation purposes, it matters not that the sender did not know those bits were being used thusly--those bits actually do carry specific meaning--just not to the sender.
At some level in architecture, you have to look both ways
and amalgamate the meanings, such that the common meaning
is useful looking in either direction.
Not a miff--just a statement of what architecture is.