Help needed. Spoofing device-id of passing-through gpu breaks monitor connection

[rdmitry0911]

I'm trying to spoof device-id of my radeon 550 gpu which I pass throug to a vm. What I'm doing is this:

• I'm adding a pci device related to my gpu to passthrogh in proxmox vm config web interface. It adds this line to a vm config file

hostpci0: 0000:02:00.0,pcie=1,x-vga=1

• I start vm and check the passthrough is working
• I run this command in proxmox shell and select a line related to my device

qm showcmd  103 --pretty|grep device

• I add new device-id in the end of this line
• I add thу resulting line to the end of args line in vm config file located in /etc/pve/qemu-server/

As a result I have this addition to args line in vm config file:

-device 'vfio-pci,host=0000:02:00.0,id=hostpci0,bus=ich9-pcie-port-1,addr=0x0,x-pci-device-id=0x67ff'

• I remove hostpci0: 0000:02:00.0,pcie=1,x-vga=1 line from vm config file

Now I start the vm. Spoofing works, however, the monitor attached to the gpu doesn't work. I can't even see a proxmox uefi logo during bootup. Replugging monitor and changing connectors doesn't help. As far as I remove this spoofing device-id addon

,x-pci-device-id=0x67ff

from the args line in vm config, monitor gets alive.

How to fix this?

Thank you, Dmitry

 

[T.Herrmann]

Hi Dmitry, If you need this for MacOS, this won't work. You can read this post and that could be work for you. https://forum.proxmox.com/threads/amd-radeon-rx6950xt-spoofing-for-macos-vm.125901/

 

[rdmitry0911]

Hi Dmitry, If you need this for MacOS, this won't work. You can read this post and that could be work for you. https://forum.proxmox.com/threads/amd-radeon-rx6950xt-spoofing-for-macos-vm.125901/

Ok, thank you. I managed to resolve the gpu related problem and posted the solution here Now the only problem is that proxmox uefi does not initialaize my gpu when tv is connected. If monitor is connected then gpu is intitialized properly. A workaround (very inconvinient thou) is either to connect any monitor to gpu at start and then reconnect it to the tv or to include a standard vga adapter into vm config as a secondary graphic device.

 

[T.Herrmann]

Ok, thank you. I managed to resolve the gpu related problem and posted the solution here Now the only problem is that proxmox uefi does not initialaize my gpu when tv is connected. If monitor is connected then gpu is intitialized properly. A workaround (very inconvinient thou) is either to connect any monitor to gpu at start and then reconnect it to the tv or to include a standard vga adapter into vm config as a secondary graphic device.

Thank you, very interesting, that PCI Path is changing PciRoot a little bit if change the OSTyp.

VM OSType Other:
IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/SE0@1C/IOPP/GFX0@0
PciRoot(0x1)/Pci(0x1C,0x0)/Pci(0x0,0x0)

VM OSType: Win10:
IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/SE0@1C/IOPP/GFX0@0
PciRoot(0x0)/Pci(0x1C,0x0)/Pci(0x0,0x0)

Best Tim

 

[rdmitry0911]

Ok, thank you. I managed to resolve the gpu related problem and posted the solution here Now the only problem is that proxmox uefi does not initialaize my gpu when tv is connected. If monitor is connected then gpu is intitialized properly. A workaround (very inconvinient thou) is either to connect any monitor to gpu at start and then reconnect it to the tv or to include a standard vga adapter into vm config as a secondary graphic device.

Finally I’ve made my gpu to work with the tv. Ther problem was deep color hdmi settings in the tv. It was set to “optimize for 4k”. I set it to “off” and now gop detects the tv at bootup.