Can't Unbind GPU for Passthrough Unless I unplug my Display Port cables

Operating Systems & Open Source Virtualization
1

I have spent the better part of two days trying to setup a single GPU passthrough, following many guides including this Rising Prism one.
But no matter what scripts or guide etc I use, I was unable to unbind amdgpu. This is regardless of whether I use modprobe -r amdgpu or virsh nodedev-detach etc.

The ONLY way I have been able to succeed in unbinding amdgpu, is to physically unplug my Display Port cables from the GPU, BEFORE attempting to unbind. Which, ok it works but is incredibly inconvenient, especially with my current setup.

So I ssh in, I unplug my cables, I run sudo virsh start win10, wait for it to succeed, if I VNC in I can see the windows vm etc. Also sudo virsh destory win10 will also hang and never finish unless I unplug my display port cables…

Does anyone have any clue as to what is going on here? How do I even begin to figure out what specifically is causing this issue? Any help would be appreciated.

OS: CachyOS x86_64
Host: MS-7C95 (1.0)
Kernel: Linux 6.19.9-1-cachyos
Display (LS32DG30X): 1920x1080 in 32", 60 Hz [External]
Display (DELL C2422HE): 1920x1080 in 24", 60 Hz [External]
DE: KDE Plasma 6.6.3
WM: KWin (X11)
Terminal: konsole 25.12.3
CPU: AMD Ryzen 5 5600 (12) @ 4.47 GHz
GPU: AMD Radeon RX 6700 XT [Discrete]
Memory: 5.08 GiB / 31.26 GiB (16%)
Swap: 1.64 MiB / 31.26 GiB (0%)
Disk (/): 32.07 GiB / 931.01 GiB (3%) - btrfs

2

Ok so I did figure this out, but unfortunately due to busyness and family using my computer I lost the pages that helped me.

TLDR: It was the displayport specifically to a Dell Monitor, change to HDMI

This is gonna be rambley sorry. So essentially I found a thread on I the Cachy Forums where they mentioned DP power issues and linked to a thread from some AMD devs who mentioned a patch (I’m so sorry) to solve this issue. Apparently they’d done all they can and the rest would have to be handled by the monitor manufacturer (DELL). So I looked for a firmware update but none of the updates even mentioned a similar issue so I doubt that would help. So I just changed my DP in my Dell C2422HE to a HDMI cable and magically the issue is gone. I can now unbind the GPU.

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