[SOLVED] GPU passthrough strange behaviour AMD RX 5500XT GPU on 2nd gaming vm Proxmox 8.02 VE only function after enabling virtio-GPU as Display

[ZelliBigED]

Hello togehter,
till now I only red this forum passive, but now I want to share my experience:

I have 2 GPU installed and I am using proxmox 8.02 VE on a Threadripper 3970X as my virtual LAB.
I have some VMs up and runnig and just for me and my daughter, to game little, I decided to put a 2nd GPU on and just to have some fun and to educate her a little.
I have had lost some days on setting up my 2nd gaming vm.
The solution was to set first disable resizable bar in BIOS / UEFI settings and after I used to start the win 10 vm with virtio-GPU Display, all worked fine.
Standard display won't function, after all and also enabling or disabling it I always got the GPU 43 Error on the AMD GPU.

I will try now to activate again resizable bar and above 4G decoding and so on, to be for sure that it only was the display option virtio-GPU that led to function properly. Afterwards I disabled Display Option, still working.

On my long journey I bind vfio drivers at early boot, blacklisted drivers, vendor reset and much more to get it working, nothing seemed to help.

Did anybody else have had such a phenomenom?
I have used very often GPU Passthrough on Linux and also on Proxmox but never have had an error like this, but also have had only nvidia GPUs.
This was my first AMD RX 5500XT AMD GPU I used.

The other gaming vm GPU is a nvidia RTX 3080 TI and there it worked all like a charme.
Both vm were identically cloned from one base vm only keyboard, mouse, soundcard and gpu etc. added on.

Thanks for your time maybe it could als help someone with simillar issues.

 

[leesteken]

I will try now to activate again resizable bar and above 4G decoding and so on, to be for sure that it only was the display option virtio-GPU that led to function properly.

Nopte that Resizable BAR (SMA, CMA) is not supported (yet) by QEMU/KVM and Proxmox.

This was my first AMD RX 5500XT AMD GPU I used.

You might want to install and setup vendor-reset to work-around the reset issue of that GPU. My experience with recent Proxmox kernel versions is that activating vendor-reset is enough and you don't really need other work-arounds.

 

[ZelliBigED]

Nopte that Resizable BAR (SMA, CMA) is not supported (yet) by QEMU/KVM and Proxmox.

You might want to install and setup vendor-reset to work-around the reset issue of that GPU. My experience with recent Proxmox kernel versions is that activating vendor-reset is enough and you don't really need other work-arounds.

OK Resizable Bar checked, it is not working, above 4G decoding as option in BIOS / UEFI works fine.
Vendor reset ist also installed it was not mentioned under my lomg journey.