Hello,

 

I'm trying to setup a passthrough to my RTX 3090 TI with my Windows 11 VM to do some cloud gaming.

There is no screen connected to the card, just a dummy HDMI plug.

 

My unraid system has 2 cards :

1. RTX 3090 Ti for VM Gaming
2. Quadro P620 for Unraid, Plex, dockers, ...

 

The Windows 11 VM is not new, it was working perfectly with VNC and RDP has been allowed.

I have a NVME SSD and a network card already configured in passthrough to the VM.

 

Here's what I'v done as of now :

• Bind to VFIO the card :

 

• Because I had a warning message in the KVM logs, I modified my syslinux.cfg with video=efifb:off (no warning anymore)

 

• The VM has been configured with the graphic card :

 

• I added the multifunction='on' to the XML template.
• I tried to modify the VM type from Q35-6.2 to Q35-7.1

 

The VM starts but does not go online, I cannot reach it through RDP, it seems the network stack does not even go up as I can't ping it.

I have attached my diagnostic file and the XML of my VM.

 

dune-diagnostics-20221020-1412.zip VM_Template.xml

Edited October 20, 20223 yr by hot22shot

Hey take a look at the bug report I filed.

 

 

Try recreating the VM and point it to the original vdisk.

Not sure I have the same issue as I can go back and forth from VNC to the 3090 (even though I have a black screen) without the message you have.

I'll try to plug a monitor on the 3090 to see if something is shown at boot.

 

Edit : I tried to plug a monitor on the HDMI connector of the GPU, without any luck.

Nothing is displayed and the monitor just goes in save mode because it does not receive any signal.

 

I also tried to create a recreate the VM and point it to my old vdisk, same result.

 

With some dumb luck I have successfully dumped the vbios of my card with @SpaceInvaderOne script, but even with that it does not work.

 

RTX3090TIFE.rom

Edited October 20, 20223 yr by hot22shot

Yesterday I made some tests with 2 new fresh VM, one Windows 10 and the other one Windows 11.

None of them were able to boot once the GPU was associated to it.

 

@SanderScamper it seems I have now the same issue as you, my initial Windows 11 VM display the same thing.

 Ok I have finally solved my boot problem, thanks to 2 links : 

• https://forum.level1techs.com/t/solved-rtx-3090-gpu-passthrough-just-displays-a-black-screen-with-qemu/175538/3
• https://www.reddit.com/r/VFIO/comments/qx4rg7/can_anyone_else_confirm_that_vfio_doesnt_work_w/

The root cause was that my card supports Resizable BAR and that it have lots of memory (24G), it then reach the default limit adress space of the OMVF UEFI :

Quote

 

the default mmio address space for edk2/ovmf is 32GB, since the bar size option doubles each time you need a 32GB BAR for a 3090 to fit the 24GB of ram (which you should see in lspci), this means that there isn't enough address space to fit the 3090's bar alongside other devices.

The fix for this is to extend the available mmio space for the guest to 64GB instead and then it should work fine.

 

 

I just applied the specific settings in the XML form view and now it works, see attached file for an example.

 

VM_Template_Fixed.xml

Edited October 22, 20223 yr by hot22shot

Hey sorry my thing didn't help, but I'm glad you've solved your issue! Thanks for communicating it back, it's super interesting.