Comment 11 for bug 1853083

Answering comment #4:
> What I don't understand is ppc64 for IBM machine emulation, but qemu ppc64
> can't support AIX most of the time, but can support Linux on power very well.

QEMU doesn't implement the full PAPR specification. Historically we've only
added the bits that are essential for a Linux guest to be happy.

AIX 5.1 is fairly old and neither IBM, nor the QEMU community invested time
and effort in getting it to work under QEMU. AIX being a closed source OS
certainly didn't help things to go forward.

Things have changed recently though. IBM added virtio drivers and some
workarounds to AIX, as well some fixes to QEMU. Latest AIX 7.2 releases
should now be able to run under QEMU with a POWER8 or newer CPU model.