Re: Qemu / KVM On Powermac G5 MP970

[BALATON Zoltan]

On Thu, 19 Jan 2023, Dan Whitehouse wrote:
> I’m running Debian from ports (64-bit) on my G5 as the host.
> Thanks for your advice - attempting to install a 64-bit Debian guest was 
> my next target, although I believe I struggled with that when I tried it 
> before (hence the 32-bit guests!).

You of course need a 64 bit machine from qemu-system-ppc64 for that and a 
Linuc distro that works on it. I've tried a live CD from 
https://www.adelielinux.org/ which I think supports real G5 Macs with

qemu-system-ppc64 -M mac99 -m 1g -boot d -cdrom 
adelie-live-mate-ppc64-1.0-rc2.iso

on x86_64 host (which means only TCG) and this boots at least so you could 
verify it also works with TCG on a G5 Mac host then with KVM then go on to 
32-bit PPC versions with qemu-system-ppc. Starting from some known working 
guest is always a good idea to avoid problems with guests that don't run 
on the real hardware either which can also happen as PPC Linux is not too 
active nowadays. So use what's known runnning on your host or something 
known running on the guest you're emulating at first and add factors one 
by one instead of trying to boot MacOS 9 on KVM right away which is known 
not to be easy.

> I wasn’t actually sure if KVM would work with a 32-bit guest even if I 
> could get it working hence my question.
> I’ll read through those links.

It should work but there could be bugs and some guests may work while 
others don't. It seems Linux guests may work but others like MacOS9 or 
MorphOS don't and the point should be to find out why so it can be fixed 
eventually. Bugs can be both in QEMU or KVM module in Linux kernel so you 
should learn how to get traces from these for debugging. I've tried to 
give pointers to that in previous messages. For QEMU there's the -trace 
and -d options but for KVM Linux traces may be more useful which are 
accessible somewhere in /sys filesystem I think but haven't used those 
much so search for docs ot try links I've sent.

Regards,
BALATON Zoltan