QEMU GPU vfio-pci pass through

an article from a while ago, in Italian

https://www.commodorecomputerblog.com/search/label/A-Eon

Great document:
AmigaOS from Computer Science to Religion:

https://mega.nz/file/zgA0yCoZ#M-dT9wKs ... RkLD5EE3MSthjeh7NZgqcx0xM

Another interesting little article Dave Haynie:

https://www.appuntidigitali.it/15622/d ... formazioni-e-riflessioni/

I reply here to not spam the Kyvos thread.
AmigaOS apparently does not have an HDMI audio driver so even if you can pass through the sound function of your card and in theory this could work it doesn't because AmigaOS can't output sound through that.
The emulated sound cards (of which AmigaOS can use at least via-ac97 and ES1370) go through your host's audio system and works well as long as you run QEMU as you user. Your problem, which is not related to QEMU in any way, is that on your Linux distro applications run as root cannot connect to the sound server for some reason. Ask on the support forum of your Linux distro about how to solve this not here as we don't know.
If I had the same problem I would uninstall all of pipewire and pulseaudio and just use plain alsa which should work even as root but on some distros it may not be that simple as it may have dependencies on these. Even if pipewire and pulseadio cannot be uninstalled you can try to disable it with systemctl so they are not started and then use alsa or you can try to switch to jack which should also work.
I've explained this before several times but it seems you don't get it so you ignore it and keep looking for a solution somewhere else where the problem cannot be solved.

@Balaton

I tried removing Pipewire, but uninstalling it basically wipes out half the Ubuntu system. I even installed ALSA, so much so that I had to log back into the shell and reinstall Pipewire, otherwise nothing would start.

Anyway, I appreciate the various suggestions.
But this is a problem I'll try to solve on my own.
Because I see that the problem is only with my hardware.

I'm just sorry I don't have access to Virtio-GPU, but I imagine the audio problem would persist.
Because I would use it for many things.

I'm not young anymore, and I don't have the friends I used to have
Otherwise, I would have invited some friends over like I used to, and I would definitely have solved the problem

I have never used Ubuntu but always other Linux systems in this case I am using it because I didn't want to complicate things for myself.
Instead I got exactly the opposite.

Thanks anyway.

@Balaton
I followed your advice.
I stopped PipeWire (not uninstalled it).
I installed Jack.
Rebooted.
I started the Jack server.

Same problem. As soon as I use sudo to switch the GPU, the audio is lost.

Something changed over time in the Qemu compilation.
Now I have to add --slirp to use the network with AmigaOS.

For example, if I do:
./configure
to install the entire Qemu package, the network isn't recognized by AmigaOS.

I just wanted to close the topic and let you know that I followed your additional advice.

Well, I must be unlucky.
And yet, both GPUs are recognized and work without problems.

Never mind, you can't have everything

@white
Quote:
The problem is not with QEMU/AmigaOS nor with your hardware but with the settings of the Linux distro you use. Why not try a different Linux distro if you can't fix Ubuntu. You said you prefer another distro anyway so maybe it's easier to fix sound on that.
Does QEMU use the audio backend you want? Check output from configure, it has an Audio backends section. On my machine it only says YES for OSS, ALSA and JACK and I don't have pipewire or pulseaudio so no problem with that but there are options to disable those backends when compiling QEMU so it won't even try them. Try configure --with-alsa --without-pa --without-pipewire to make sure you have alsa working.

@white
Quote:
I don't have acces to it either but I think it does not need to run QEMU as root so it would work but you may need QEMU compiled with some patches on some hosts so maybe you'd get other problems instead.

@Balaton

I'm sorry you don't have a Virtio GPU. (driver)
You'd have every right to.

I understand why it's not available to me for many reasons.

Aside from that, I'll switch to another distro later.
Now I want to do something else.

WinUAE is more than enough to use a 68K system perfectly
to relive the AmigaOS moments
If you don't feel like configuring the 68K, you can download Coffin and it's all set.
even though I use another 68K system.

I have to be honest, I imagine, but I could be wrong, that they'd want to build a machine for around €1000 with a Virtio GPU.

It's still very expensive for what it would offer.

We'll see in time.
Have a good day.

And thanks again for your advice.