Thanks for the PSA, That warning is more for the xen side of things, but yes, on KVM, Nvidia should be fine.

The second part about signing drivers and anti-cheat will sound really scary to anybody none the wiser to the first part if they glanced over it. So for their sake, just to clarify, by adding a few steps to the original setup procedure, Nvidia cards will work no problem, without test signing, or worry of anti-cheat.

It’s not like it’s insanely hard to hide the hypervisor from the drivers.

Absolutely. You need to hide the kvm extensions from the vm, or you’ll need to patch the Nvidia drivers (requires test signing mode in windows which can set off anti-cheat software) but it will work.

The reason for having a 1080 is to play games on a 120Hz screen. Is possible to do that with passthrough?

As Kyle mentioned, This build is designed to skirt all the pitfalls of vfio setup for newcomers. While cards up to about a 1070 would work well in this system, the 570 is compatible and stays within the scope and budget of the build.

The gtx 1080 is really only required for 144hz or 4k gaming, so unless you’re doing either of those, you likely won’t need a 1080. The reason Tyson recommended the AMD card is that Nvidia intentionally disables their drivers for GeForce cards when it detects its in a vm. If you are willing to go through a process to hide the hypervisor from the drivers, they’ll work fine, but this article is designed for those who want a solution with the least difficulty or resistance.