GPU PCIE Passtrough - Nvidia High Definition Audio Device available -> no Audio Device

[DeineMudda_1981]

Dear Proxmox community

I'm getting mad with my problem. Therefore I am now turning to the International Forum, in the hope that you can help me.

I have the problem that I cannot get one of my Proxmox servers to output the audio signal via HDMI from a GTX1080TI graphics card connected via PCIE passtrough. I've tried everything possible and can't get any further.

I have another Proxmox server in operation in which an Nvidia Quadro P400 runs for a VM with passtrough. Everything works fine here. To check, I tested this card in the system with the 1080TI. With the same result: no Nvidia high definition audio device. Therefore no sound. Although it works with this card in the other Proxmox server. However, the image is output hardware-accelerated via the GPU without any problems.

So I think it's a problem with the server's host system. Either a little something is wrongly set in the BIOS or there is a problem with the hardware itself. However, I have also found configs with comparable hardware where it also runs perfectly.

My hardware:
I7 6800k
Gigabyte GA-x99 Ultra Gaming Motherboard
32GB RAM
Nvidia GTX1080TI - secondary card for guest VM
Nvidia 8200GS - primary card for host

I have already tested various configurations.
IOMMU is activated

The Nvidia High Definition Audio Device is simply missing, which is why the driver for it cannot be installed. The graphics card is output to the VM complete with all functions via PCIE pass-through. Even if I release the graphics card and the audio from the graphics card individually to the VM, the problem does not change. Repositioning the cards in the slots did not improve the situation either.



Do you have any ideas what else I can do?

 

[leesteken]

Did you make sure the snd_hda_intel driver of the Proxmox host does not touch the audio device of the GPU? This can be done either by blacklisting that driver or binding vfio-pci using the ids of the device. I don't know what you did for the VGA device of the GPU.

 

[DeineMudda_1981]

Did you make sure the snd_hda_intel driver of the Proxmox host does not touch the audio device of the GPU? This can be done either by blacklisting that driver or binding vfio-pci using the ids of the device. I don't know what you did for the VGA device of the GPU.

Thank you for your reply. Can you explain how i can check that in detail?

if you mean the entrys in the /etc/modprobe.d/pve-blacklist.conf
I did add this lines:
blacklist nvidiafb
blacklist nvidia
blacklist radeon
blacklist nouveau

But now i think i did understand what you mean. The snd_hda_intel is the used driver for the Audio Device.
How can i check if it is used or not?

 

[leesteken]

Thank you for your reply. Can you explain how i can check that in detail?

If you reboot the Proxmox host and don't start the VM, is the snd_hda_intel driver in use or vfio-pci? You can check with lspci -ks 05:00.1. If the snd_hda_intel is the kernel driver in use, then either blacklist it as you did for nouveau etc. or use vfio_pci.ids=xxxx:yyyy kernel parameter (use lspci -ns 05:00.1 to find the id), or add a line with options vfio_pci ids=xxxx:yyyy to /etc/modprobe.d/pve-blacklist.conf, to bind the vfio_pci driver before snd_hda_intel.

 

[DeineMudda_1981]

If you reboot the Proxmox host and don't start the VM, is the snd_hda_intel driver in use or vfio-pci? You can check with lspci -ks 05:00.1. If the snd_hda_intel is the kernel driver in use, then either blacklist it as you did for nouveau etc. or use vfio_pci.ids=xxxx:yyyy kernel parameter (use lspci -ns 05:00.1 to find the id), or add a line with options vfio_pci ids=xxxx:yyyy to /etc/modprobe.d/pve-blacklist.conf, to bind the vfio_pci driver before snd_hda_intel.

yes, i checked that:

Because i changed the slots the GPU now has the 04:00.1
Result:
04:00.1 Audio device: NVIDIA Corporation GP102 HDMI Audio Controller (rev a1)
Subsystem: ASUSTeK Computer Inc. GP102 HDMI Audio Controller
Kernel driver in use: vfio-pci
Kernel modules: snd_hda_intel

So it looks like that the snd_hda_intel isnt touched right?

Additionally i added teh line into the /etc/modprobe.d/pve-blacklist.conf. Now its this:
blacklist nvidiafb
blacklist nvidia
blacklist radeon
blacklist nouveau
options vfio_pci ids=10de:10ef

 

[leesteken]

yes, i checked that:

Because i changed the slots the GPU now has the 04:00.1
Result:
04:00.1 Audio device: NVIDIA Corporation GP102 HDMI Audio Controller (rev a1)
Subsystem: ASUSTeK Computer Inc. GP102 HDMI Audio Controller
Kernel driver in use: vfio-pci
Kernel modules: snd_hda_intel

So it looks like that the snd_hda_intel isnt touched right?

It depends, did you reboot the Proxmox host and not start the VM before running this command?
If so, then there is a file in /etc/modprobe.d/ what has a line with options vfio_pci, or your /etc/default/grub or /etc/kernel/cmdline contains kernel parameters with vfio_pci.ids.Tthe _ can also be a -.

 

[DeineMudda_1981]

It depends, did you reboot the Proxmox host and not start the VM before running this command?
If so, then there is a file in /etc/modprobe.d/ what has a line with options vfio_pci, or your /etc/default/grub or /etc/kernel/cmdline contains kernel parameters with vfio_pci.ids.Tthe _ can also be a -.

I am not sure if i understand you correct.
First, yes, i did a fresh reboot and didnt start a vm.

SO now i need to check in the /etc/modprobe.d/ about a file?
Can you please explain how i should to that in detail? Wich commands?

Sorry for my neewbe questions...

 

[DeineMudda_1981]

that?

root@buero:~# cd /etc/modprobe.d/
root@buero:/etc/modprobe.d# ls
iommu_unsafe_interrupts.conf pve-blacklist.conf vfio.conf

iommu_unsafe_interrupts.conf :
options vfio_iommu_type1 allow_unsafe_interrupts=1

pve-blacklist.conf:
blacklist nvidiafb
blacklist nvidia
blacklist radeon
blacklist nouveau
options vfio_pci ids=10de:10ef

vfio.conf:
options vfio-pci ids=10de:1b06,10de:10ef disable_vga=1

 

[leesteken]

No need, then the problem cannot be that snd_intel_hda touches the audio device. Sorry, I am out of ideas for now.

EDIT: Does this work for you? Some people find that it works for some monitors and not for others. Have you tried a different display, or tested your display with another GPU? Maybe try a Linux VM (instead of Windows) and see if it is a NVidia driver issue?

 

[DeineMudda_1981]

No need, then the problem cannot be that snd_intel_hda touches the audio device. Sorry, I am out of ideas for now.

same here... Thank you very much anyway for your help.
So, it looks correct right? Can it be a hardware issue of the the cpu or the mainboard?
i am very sad that i cant bring it to work. :-(

 

[DeineMudda_1981]

No need, then the problem cannot be that snd_intel_hda touches the audio device. Sorry, I am out of ideas for now.

EDIT: Does this work for you? Some people find that it works for some monitors and not for others. Have you tried a different display, or tested your display with another GPU? Maybe try a Linux VM (instead of Windows) and see if it is a NVidia driver issue?

Great Idea! I tryed, but nothing happens. I also tryed 2 different monitor types. Nothing changes :-(
I now setup an Ubuntu VM to check if there is some sound...

 

[DeineMudda_1981]

ok, i did a ubuntu install with the same setup as the windows machine.
During the installation i got some sounds, but they are not correct. The sound is like in a echo and repeating and lagging.
When i try to start a video in youtube the sound lags again and the video stutters,
What do we know now?
That there is a problem with a driver? Or is the problem more hardware related and maybe because of my setup?
The p400 doesnt work also in that system but works without any problems in a different system.
So it must be a Hardware Problem? I think not because of the gpu. I guess it is maybe the mainboard? Would it be change if try a different mainboard with a different chipset?