I had tried to passthrough my (only) GPU with mixed results. I thought I'd make my life easier by buying a second GPU. Unfortunately, it didn't solve my issue.

 

My Win10 VM is running very well. When I tried to change the GPU from VNC to Nvidia-passhtrough (using my second GPU in 2nd slot), my VM still starts, but it only shows a black screen. I tried to disable PCIe ACS and also disable Hyper-V. Still no improvement and I cannot get the GPU passthrough to work.

Any idea? What info would be helpful for trouble-shooting?

Spent the last two days trying to come up with a solution to pass-through one of my Nvidia GPUs to my WIndows 10 VM. Unfortunately, I can still not get the Nvidia passthrough to the Win VM to work.

 

In the meantime, I have set up a Fedora VM and it works to passthrough both of the Nvidia GPUs (individually, not at the same time).

 

However, it still not working with my Win10 VM. See below what I have tried:

 

* Enable PCIe ACS override: yes

* Hyper-V: No

* Bios: Seabios (requires new install of Windows, so didn't try to change)

* Tried both GPUs individually

* Manually added vbios rom file to XML (dumped via commandline or downloaded from techpowerup)

 

I am really running out of the options what I can still try to make it work. Setting up a new Win10 VM with OVMF bios may be an option, but this will be huge work and I'd need to buy another license. And it used to work for a short time period before, so there must be a way to get it to work with Seabios.

 

Any other idea what I can do? I am getting quite desperate. Let me know if any diagnostic or related info may be helpful. Thanks!

Here we go with the log from the VM. Maybe this helps the experts?

 

https://pastebin.com/HUfrvTW7

If your Graphics card is older than the 600 series, it will not work. I learned that the hard way.

My GPU is a GTX1050, so this should not be the issue. Actually, I even have two GTX1050.

 

I created a second Win10 VM with OVMF and now things work. So, Seabios is the issue. I used to have things working with Seabios though. Any idea what I can still try. Would love to keep my first Win10 VM (with Seabios) and now passthrough the second VM. Would this work?

There is an excellent 2 part video series from SpaceInvader One on YouTube. Search for Daily Driver. The second part covers passthrough.

 

I followed them and worked, and I have very similar config as you.

 

If you are passing through primary video there is another video that instructs to add a ROM file. He demonstrates passing through 2 video cards.

 

Good luck!