R: Qemu / KVM On Powermac G5 MP970

Luigi,

Thanks for getting back to me.

I just tried:

qemu-system-ppc \

-L pc-bios \

-boot c \

-M mac99,via=pmu \

-enable-kvm \

-cpu g4 \

-m 2048 \

-prom-env 'auto-boot?=true' \

-prom-env 'boot-args=-v' \

-prom-env 'vga-ndrv?=true' \

-drive file=/srv/Qemu/debian_32bit.qcow2,format=qcow2,media=disk \

-netdev user,id=mynet0,net=192.168.76.0/24,dhcpstart=192.168.76.10 \

-device sungem,netdev=mynet0 \

-monitor stdio

And that doesn’t work for me (same dmesg output about illegal instructions).

It’s really interesting that your kernel is a lot older than mine. I would avoid updating it if you want to keep using KVM!

I also found this thread which looks like too much of a coincidence to me:

Kernel 5.8 - Page 3 - Hyperion Entertainment Message Boards

forum.hyperion-entertainment.com

I’m going to try and install 5.6.14 and see if I can get it to work.

Thanks for your help. This is beginning to feel more like a kernel / kvm issue than a Qemu one.

On 24 Jan 2023, at 10:37, luigi burdo <intermediadc@hotmail.com> wrote:

I Dan,

on my G5 i have Debian sid ppc64 and the kernel is my last build the 4.8

About the issue you are find with kvm. Did you test an old version of qemu? Did you try to force the cpu setting with mac99? example -cpu g4?

Ciao

Luigi

Da: qemu-ppc-bounces+intermediadc=hotmail.com@nongnu.org <qemu-ppc-bounces+intermediadc=hotmail.com@nongnu.org> per conto di Dan Whitehouse <drw@dim-sum.org>
Inviato: lunedì 23 gennaio 2023 15:42
A: luigi burdo <intermediadc@hotmail.com>
Cc: qemu-ppc@nongnu.org <qemu-ppc@nongnu.org>; BALATON Zoltan <balaton@eik.bme.hu>
Oggetto: Re: Qemu / KVM On Powermac G5 MP970

Hi Luigi,
It doesn’t work for me at all:

crab@powermac-g5:~/Documents/Qemu$ uname -a

Linux powermac-g5 6.0.0-6-powerpc64 #1 SMP Debian 6.0.12-1 (2022-12-09) ppc64 GNU/Linux

crab@powermac-g5:~/Documents/Qemu$ lsmod | grep kvm

kvm_pr 110777 0

kvm 309830 1 kvm_pr

#!/bin/bash

qemu-system-ppc64 \

-boot c \

-M mac99,via=pmu \

-m 2048 \

--enable-kvm \

-drive file=/srv/Qemu/debian_64bit.qcow2,format=qcow2,media=disk \

-netdev user,id=mynet0,net=192.168.76.0/24,dhcpstart=192.168.76.10 \

-device sungem,netdev=mynet0 \

-monitor stdio

Result:

dmesg is flooded with:

#!/bin/bash

[22936.303544] Couldn't emulate instruction 0x00000000 (op 0 xop 0)

[22936.315006] kvmppc_exit_pr_progint: emulation at 100 failed (00000000)

Exactly as described here:

Re: [PATCH 2/9] target/ppc: add errp to kvmppc_read_int_cpu_dt()

mail-archive.com

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Can you let me know:

1./ what is your host OS and kernel version?

2./ what version of Qemu you are using? (I’m using the version in Debian ports).

3./ what arguments are you using to start your guest?

Does it also work in Libvirt?

On 23 Jan 2023, at 14:21, luigi burdo <intermediadc@hotmail.com> wrote:

Hello Dan,

on G5 you need to have the Kernel with kvm modules installed and enabled, plus use --enable-kvm on the qemu command line.

by the way on my g5 quad all the linux distros guest works really well. Only if i dont use kvm all is slow because TGC.

This is an old video (qemu 3) but all was working good in multitasking with kvm.

https://youtu.be/so35SrThHUs?t=591

Ciao

Luigi

Da: qemu-ppc-bounces+intermediadc=hotmail.com@nongnu.org <qemu-ppc-bounces+intermediadc=hotmail.com@nongnu.org> per conto di Dan Whitehouse <drw@dim-sum.org>
Inviato: lunedì 23 gennaio 2023 12:17
A: BALATON Zoltan <balaton@eik.bme.hu>
Cc: qemu-ppc@nongnu.org <qemu-ppc@nongnu.org>
Oggetto: Re: Qemu / KVM On Powermac G5 MP970

Zoltan,
I have a “toy” macos9 install which works well (if extremely slowly).
I also have Debian powerpc (32-bit) installed and that works reasonably well but slowly too.
Finally after a lot of struggle over the weekend I have an install of Debian ppc64 (64-bit) which “works”.
It’s so slow it seems to always drop me to the emergency shell because of the filesystems timing out, but there may be a way to increase that in the kernel command line. It also doesn’t seem to want to shutdown or reboot properly - but maybe passing -M mac99,via=pdu may help that. I’m testing at the time of writing. So slow progress but I almost have something I can begin testing with.

Thanks,

Dan

> On 20 Jan 2023, at 23:05, BALATON Zoltan <balaton@eik.bme.hu> wrote:
>
> Hello,
>
> Keeping the qemi-ppc list posted in case there's anybody who could add something to this or for later reference for the benefit of those trying it later so they don't have to get through the same again.
>
> On Thu, 19 Jan 2023, Dan Whitehouse wrote:
>> 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!).
>> 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.
>
> I came across this lengthy forum thread:
>
> http://macos9lives.com/smforum/index.php/topic,4600.75.html
>
> where they debugged booting MacOS9 on G5 and found the same dcbz problem the other blog posts also mentioned and also rfi vs rfid which may be a problem as well. It also shows how to enable debug logging in MacOS9 nanokernel with the AAPL,debug property in the device tree which may be useful to know how far it gets and what's happening.
>
> After verifying KVM works with Linux guest you could go on to check if at least these known instruction differences with G5 that cause problem with MacOS9 are handled correctly by KVM or check you're not getting the same problem. Even if these are handled there can be problem with BATs that aren't there on G5 so maybe you'll need some patches to MacOS9 to boot. They used QEMU with gdb to debug this but I think with TCG, don't know if the same also works with KVM. This could give you some more info on where to go next or how to debug this.
>
> Regards,
> BALATON Zoltan

From:	luigi burdo
Subject:	R: Qemu / KVM On Powermac G5 MP970
Date:	Tue, 24 Jan 2023 11:35:02 +0000