AMD Ryzen with Two Nvidia GPUs, One for Host, One for VM Passthrough?

[coolspot]

Hi all,

I have an AMD Ryzen 7 5800X based Proxmox homelab, the system is working fine, with a single Nvidia Quadro T400 in PCIe Slot 2 passed through to my Windows VM.

No issues there everything is working as expected.

What I like to do is install a second Nvidia T400 in PCIe Slot 1 to replace the temporary Radeon HD2400 for the host GPU to use in LXC and Plex.

Is there a way to selectively blacklist PCIe devices by address rather than by driver? What's the best way to keep the Nvidia T400 in PCIe Slot 1 active for the host without impacting my passthrough in PCIe Slot 2 for my VM?

Thanks.

 

[Dunuin]

Is there a way to selectively blacklist PCIe devices by address rather than by driver?

Jep, thats possible and explained in several threads here in the forum. Not sure what the exact command was but you should be able to find it using the forums seach function.

What's the best way to keep the Nvidia T400 in PCIe Slot 1 active for the host without impacting my passthrough in PCIe Slot 2 for my VM?

In BIOS/UEFI you often can select the GPU that should be the primary GPU that is used while booting. So you might want to select the slot1 GPU there.
And after adding a second GPU the address of your old GPU might increase by one so you might need to edit the VMs config once so the VM is using your slot2 GPU again. Same with NIC names that might change when adding a new PCIe device.