After many tweaks, still a black screen, posting the current state of my setup in case anyone has any suggestion that might help:
Bios settings:
SR-IOV: disabled (also tried enabling)
CSM: disabled (also tried enabling)
ReBar: disabled (also tried enabling)
ACS override: none
Iommu: enabled
AER: enabled
amd-VI: enabled
bios: 1.28 (x670e steel legend)
I’m using stubs for the driver, it’s working flawlessly, i cannot find any errors in dmesg nor journalctl. Everything seems like it should be working. Windows boots, i can hear it and access through VNC, but all i get on my DP connection is a black screen. I plugged in another set of keyboard and mouse so i can debug without hard rebooting as well.
Stubs working:
03:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 31 [Radeon RX 7900 XT/7900 XTX] [1002:744c] (rev c8)
Subsystem: ASRock Incorporation Navi 31 [Radeon RX 7900 XT/7900 XTX] [1849:5304]
Kernel driver in use: vfio-pci
Kernel modules: amdgpu
03:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Navi 31 HDMI/DP Audio [1002:ab30]
Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Navi 31 HDMI/DP Audio [1002:ab30]
Kernel driver in use: vfio-pci
Kernel modules: snd_hda_intel