qemu amigaos 4.1 sudo without no audio

@white
Quote:
Only if your monitor have multiple inputs or you use a monitor switcher because the two GPUs have their own outputs so you'll need to plug them somewhere to see their picture. You have two machines: your host and the virtual machine that now uses it's own graphics card so you need two monitors to view the output of two machines or any other way you would use to view two machines. That's why it's called a virtual machine, because it's like a real one just lives inside the host machine and not a physical one.

I think the QEMU_AUDIO_* env variables were removed in later QEMU versions and won't work in current version regardless of what ChatGPT told you. To configure audio backend in QEMU now you have to use the -audio option but that's not normally needed. If you haven't set any QEMU_AUDIO variables then they aren't there. You can check with set | grep QEMU and if that returns nothing then it's some other env variable needed by pipewire that needs to be preserved for sudo.

Edit: Here's the commit that removed QEMU_AUDIO_DRV almost 2 years ago.

@balaton
Thanks for the explanation
Now I can try so many things. Before, without audio, it was pointless for me.

I'll leave the sysmon screenshot:




Then, if (vokoscreenNG) allows it, I'll take some videos on the second monitor

@Balaton

I could use KVM x64 Nvidia GPU and run Arch-Linux directly, then emulate Qemu-PPC Radeon GPU inside it and use a single monitor. I did this with FS-UAE and used a single monitor.

I wonder if that would work and if speed would suffer.

@white
Quote:
Apparently you did not understand the explanation. How would you make a video on one machine of the monitor of another machine? So this won't work the way you might think. You would either need to make video on the guest but vokoscreenNG does not run there or maybe you need a video capture card where you plug the guest's GPU so you can view it on the host in a window then you can make a video of that. Remember that you have two separate machines with their own video cards. Forget that one of these is a virtual machine in the host, it still behaves like a separate machine.
Quote:
I don't even understand that. You can't use a single monitor with vfio-pci as the guest uses a dedicated GPU different from the GPU of the host. I doubt you did that with FS-UAE as it can't use vfio pass through of real GPU as far as I know. The only way to use a single monitor is to use separate inputs on the monitor and you then can switch between the two machines but can't view them on the same screen (unless your monitor does picture in picture but you can't record that).

@Balaton

Sorry, I read it correctly now.
I have this main monitor. It has 2 HDMI ports, 1 display port, and 1 VGA.
So it should work with a switch ?

@white
Did your monitor come with a manual? Maybe try reading that. As I said think of it like having two machines each with their own graphics card. You can connect two machines to this monitor and then you can view one of them by selecting the input you want to watch. Some monitors can even show multiple inputs at the same time often called picture in picture but that only happens in the monitor so you can't record that in the host that way.
You get lost because you're not specifying your goal clearly. Is your goal to view both machines on one monitor (then a monitor with multiple inputs will do but you can only view one at a time) or view both without having to switch on the same screen (then a monitor that can show multiple inputs is needed) or is it to record the guest (in that case you need to digitise the output of the virtual machine and show that on the host so you need a capture card in the host for that).

@balaton
Thanks for the explanation.
Now I understand what you meant.

note:
Paolo Bonzini, I think he participated in some way to the Virtio-GPU Driver for AmigaOS but I could be wrong I had read something about the QEMU commit.

@Balaton
Good, I'm doing some testing.
Now I'm working on it a bit on AmigaOS.

Thanks again for your work

I uploaded this demo, recorded with my phone, just to get started with the GPU and see what can be done.

I'd be curious to know what the command:
--preserve-env qemu-ppc does to fix it.

The command:
set | grep QEMU
didn't give me any results; the output is empty.

Here's a short video:

https://youtu.be/Jswch6RQkvQ

@white
Quote:
So ChatGPT suggested this but it can't explain why? Can it even tell you what the opion does or where it got it from? It looks like ChatGPT managed to help you by chance and not because of any intelligence. The 'set | grep QEMU' verified that you have no enviroment variables related to QEMU so this has nothing to do with QEMU_AUDIO_DRV mentioned by ChatGPT. Also all the other env variables it mentioned are irrelevant. Pipewire or Pulseaudio or whatever your distro uses may depend on some environment variables though to know where and how to connect and these are not preserved in sudo unless using this option. I don't know which variables may those be but one of the lot printed by the 'set' command without |grep. And it's not '--preserve-env qemu-ppc' but 'sudo --preserve-env' as it's an option to sudo, the qemu-system-ppc is another argument to sudo here which is the command to run.

@Balaton
To be honest, I didn't ask him to explain exactly which files and which permissions are changed.

I was more busy seeing if the sound would work on reboot

I'll get back to that.
Now I'm optimizing everything a bit, and then I'll eventually put everything on an SSD. I have a 500GB Samsung 860
and I'd like to use that like I did a few years ago, moving everything to an SSD:
400GB Linux, 100GB AmigaOS.

I ordered the HDMI-KVM switch. It's arriving tomorrow, along with two LITTLE FISH with catnip inside.

So I can see if it's convenient.
Because even with a second monitor, I still haven't found the right configuration for Windows-Linux or managing the two Nvidia and Radeon GPUs.
Every time I have to unplug the HDMI monitor cable at boot, and when I use Qemu for AmigaOS, I have to plug in the HDMI cable, and everything works fine.

If I could get the ability to switch to a single monitor, that would be great.

I haven't seen how I could possibly modify GRUB to avoid this problem yet:

Currently:

GRUB_CMDLINE_LINUX_DEFAULT='nowatchdog nvidia_drm.modeset=1 loglevel=3 amd_iommu=on iommu=pt'

I also tried blacklisting the Radeon GPU in GRUB, but the result is the same.
I still have some work to do.
And I'm using the GPU that consumes less (6+6), not the OC version of the R9 270X, even though both work.
I've tried them.

I'm happy, but I wasted a lot of time with the audio.
Now I can finally get my hands on it

Thanks again.

Note:

However, I didn't install the Linux drivers for the Radeon. It seemed superfluous since I only needed to use it for QEMU.
Question: Or do I have to install them ?
For dual boot to work properly.

For the Nvidia ones, I installed the proprietary ones.

@white
If you only use the Radeon card for AmigaOS then you don't need drivers for it on the host. To be able to pass it through to the guest, it has to be unbound from host drivers and assigned to vfio-pci driver so the host won't use it anyway and the drivers are blacklisted to not load before vfio-pci, so it does not matter if they are installed or not. That driver won't be used anyway, but better not to install them at all, just to make sure they won't interfere with vfio-pci. So no, you don't need Radeon drivers for Linux.

I don't understand what is your problem. You said your monitor has 2 HDMI inputs (and some others). Can't you just plug in both cards in different inputs and select which one to view in the monitor's menu? It's documented in the monitors manual and if you search for it there are other detailed docs on how to do this so why do you make your life more complicated with additional switch box? But if the cats need it or you find your life too boring otherwise then it's up to you.

@Balaton

So my intuition about not installing the Radeon drivers was right.

I use a single PC with a single motherboard that has two PCI slots: one with an Nvidia 4060 and the other with an R9 270X.

I don't dual-boot.
Windows is independent of Arch Linux GRUB.

And Arch Linux is installed on a single partition with its own GRUB, which is not tied to Windows 10 in any way.

They are two separate and distinct installations.
Even though they're on the same PC, it's for personal convenience.

I don't like putting GRUB on the primary Windows partition.

When I boot Arch Linux now that I'm using two monitors,
I log in on one monitor.
Then the other monitor, controlled by the Nvidia 4060, activates.
The other monitor stays BLACK until I launch QEMU to use AmigaOS, and then the AmigaOS screen opens on the second monitor.

Basically, if I connect the two HDMI cables to the same monitor, I can't boot Linux.
If I don't have a second monitor.
Because the login window appears on the second monitor.

A little complicated, but that's how it is.
The HDMI KVM switch should solve this problem (I hope).

Otherwise, I'll use it for other things.

Even when I make backups, they're separate; they don't depend on GRUB,
and I can do them separately.
I don't have the problem that if GRUB breaks, it will somehow also damage Windows.

If the HDMI KVM switch doesn't work, I'll have to modify GRUB so that Nvidia takes control of only one monitor so I can log in there, and then use QEMU to open AmigaOS on the second monitor, as I already do.

@Balaton

In short, if I only use the Nvidia HDMI, Linux boots normally, with output on the main monitor.
I log in and control Linux on the main monitor.
But I don't have to connect the Radeon HDMI to boot.
Then, when I use QEMU, the output moves to the second monitor, and I have to connect the Radeon's HDMI to display AmigaOS.

If, however, I boot with both cards already connected, I have the problem described above.

I've described this to you because I clearly consider you a Linux expert.

ChatGPT helps me; it's much better than many Linux forums, and it's obviously more straightforward, and you can implement various solutions.
It's instantaneous, and if they don't work, you can try other solutions.


note:

Aside from this little HDMI OT,

Even ignoring this, the command:

-device bochs-display,romfile=""

still requires a second monitor to be used correctly.
Correct me if I'm wrong.
Or are there alternative solutions ?
or is it possible to redirect to the same monitor ?

Thanks