Re: [RFC PATCH] docs/about/deprecated: Deprecate 32-bit host systems

[BALATON Zoltan]

On Tue, 4 Apr 2023, Cédric Le Goater wrote:
> > Unrelated to KVM: Do you happen to know whether there are any problems when 
> > running 32-bit guests with TCG with the mac99 or g3beige machine while 
> > using qemu-system-ppc64 ?
>
> We removed rfi support for 64bit machine in QEMU 2.7.  Commit a2e71b28e8
> ("ppc: Fix rfi/rfid/hrfi/... emulation"). So a mac99 machine using a 970
> CPU needs a 64 bit kernel. The rfi insn was deleted from the ISA ...

I don't know about that issue but maybe this does not really answer the 
question. AFAIK you could still run 32 bit guests with qemu-system-ppc64 
and they seem to work. One could still get the qemu-system-ppc -M mac99 
machine as qemu-system-ppc64 -M mac99 -cpu G4 but this is very confusing 
and nobody could guess it. Other machines should work the same in 
qemu-system-ppc64, the only concern is that some defines such as 
TARGET_ULONG are different between qemu-system-ppc and qemu-system-ppc64 
and it's not known if this could cause any problems. It's more frequently 
happens that people try qemu-system-ppc64 -M mac99 when they want a G4 Mac 
and get confused that it emulates a G5 Mac instead which does not even 
work for anything than a Linux guest.

Regards,
BALATON Zoltan