Passing through two RTX 4090 to a same VM

[mjrosa]

Greetings,

I'm having a hard time configuring two RTX 4090 for our Rocky Linux in Proxmox. I managed to passthrough a single GPU by following some docs on the internet, and everything works perfectly fine. But when it comes to using two GPUs in the same VM, the VM simply freezes in a "display output is not active" screen and then I have to stop the VM.

I wonder if it has something to do with the fact that both GPUs have the same vendor:device ID, perhaps causing some conflict when passing through?

Does anyone please have any idea of what can this issue be?

Both cards are in different IOMMU groups.
Here are my VM specs:

 

[dcsapak]

hi,

in the posted screenshot, you only have one pci device configured for the vm, how does it look like when you have both configured?

also the output of 'lspci -v' and 'dmesg' (after trying to start) would be interesting.