Nvidia P620 PCI Passthrough to Multiple VMs

[amerikiwi]

I have been able to pass-through the Nvidia Quadro P620 into a single VM via the tutorial to a Windows VM:

Proxmox 8.0 - PCIe Passthrough Tutorial

However I have not been able to run two VMs using the same graphics cards. I continually get the error:

TASK ERROR: PCI device '0000:81:00.0' already in use by VMID '104'

I was under the impression that I would be able to use one single PGU for multipe VMs. Am I mistaken?

 

[leesteken]

PCIe passthrough is only possible with one VM at a time, which explains the error message. If you GPU support mediated device passthrough, then you can share (part of) it with multiple VMs (but no display output). I don't know if a P620 supports mediated device passthrough.

 

[VinnyG]

you're looking for grid drivers

 

[Anotheruser]

There are more or less currently two ways to use a single gpu in multiple vms
Nvidia VGPU - directly from nvidia, officially requires a license but can be worked around, craft computing did several very detailed videos on that.
https://www.youtube.com/watch?v=cPrOoeMxzu0
The other way would be VirtGL GPU, opensource, but only limited amount of features will work inside the vms, no nvenc encoder for example https://www.youtube.com/watch?v=TqrT6foTH6o

Both require installing drivers on the host.