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Rockingcool

Member

Registered: 2022-03-16

Posts: 8

[SOLVED] VFIO GPU Passthrough doesn't work after shutting down VM

Hey everyone,

I just built a new PC, with a Ryzen 5 5600G, and an RX 6600XT. I intend to pass the 6600XT to a Windows VM for gaming, and I've followed the arch wiki guide to set it up. There seems to be a problem, however. The GPU Passthrough works flawlessly when I do it the first time after a reboot of my host system, but fails to work every subsequent time after I shut down the VM, unless I reboot the host again. I get an error 43 on Windows. Is there something I'm overlooking? Is the GPU not being released by the VM after I shut it down?

I would be happy to post logs, but I'm unsure where virt-manager stores its logs.

EDIT: I don't know if this helps anyone, but I just noticed that the line 'vfio-pci 0000:03:00.0: enabling device (0002 -> 0003)' only shows up in dmesg when I start the VM for the first time.

Thanks in advance.

Last edited by Rockingcool (2022-06-15 03:59:15)

Rockingcool

Member

Registered: 2022-03-16

Posts: 8

Re: [SOLVED] VFIO GPU Passthrough doesn't work after shutting down VM

Ok, so I think I've solved this issue. I realized that my GPU is split into two IOMMU groups. Group 10 contains the VGA controller, and group 11 contains the audio device. I had only passed the VGA controller, while I had to pass both of them to the VM.

After doing this, the GPU is released by the VM upon shutting it down, and can be reused a second time in the VM. I had feared that it was the AMD reset bug rearing its head, but that issue is apparently not present in the RX 6000 cards.

Thanks to anyone who took their time to read my original post. I will now mark this thread as solved.