Before getting started with KVM pci passthrough for gaming

[Derheim]

Hi all,

I’ve been long time Linux user, dual booting most the time, but now that we have Proton in steam, I decided to stop dual booting and just go with Linux as my work and home PC.

I have to say, 18 years ago I would have never imagine that Linux would get to be in such a awesome state for gaming.

I will soon be upgrading my 5 year old gaming PC, I’m waiting for Ryzen 4000 to come out so I can get get started. Actually I’ll be buying a new CPU keeping only my existing RX 5700xt.

I’m planning on setting up KVM with GPU passthrough in order to run the games I can’t on linux. however there some things I still don’t or don’t understand about this kind of setup, so I have some questions that hopefully you can answer for me so I can make a better purchase decision when upgrading my PC and also deciding if it’s even worth a try.

1. Using GPU passtrough I’m guessing I will have to dedicate one monitor to the KVM machine? Unless I use something like Looking Glass
2. Does HDR works using this kind of setup? (either with a monitor connected to the GPU given to the KVM or through Looking Glass)
3. Do I need some sort of KVM switch in order to use a keyboard and mouse on the virtual machine? or is there a way to share the same keyboard and mouse between guest and host machines.

And just as a question to the community here, what’s been the biggest issues/hurdles you’ve had running this kind of setup.

Keep in mind that I’m only just planning my setup, so any advice about hardware and software is surely welcome.

Regards.

[TheCakeIsNaOH]

@Derheim

Using GPU passtrough I’m guessing I will have to dedicate one monitor to the KVM machine? Unless I use something like Looking Glass

Yes, with a third option of using a KVM, like this.

Display Port 1.4 KVM Switch - Dual Monitor — Level 1 Techs

@Derheim

Does HDR works using this kind of setup? (either with a monitor connected to the GPU given to the KVM or through Looking Glass)

If the monitor is connected directly, then yes, AFAIK. It should be no different than connecting the GPU to that monitor on a normal windows install.

As for Looking Glass, I don’t know.

@Derheim

Do I need some sort of KVM switch in order to use a keyboard and mouse on the virtual machine? or is there a way to share the same keyboard and mouse between guest and host machines.

You can use USB or edev passthrough, these can be shared or dedicated. With looking glass you can use the standard emulated devices, just like using a normal QEMU or virtualbox VM, but GPU accelerated.

[Windforce]

You can use one monitor with multiple inputs. I do just this and have host connected via HDMI with the guest connected via display port. The only annoyance with this method is having to switch the display input manually using the monitor interface as some monitors may have a one button setup to quickly swap between inputs on the fly while others may require you to actually go into a menu to switch inputs.

As for the mouse/keyboard you can use synergy. I am no professional gamer but I have used it for a couple years without any issue.

The icing on the cake would be looking glass to make things simple and convenient if you are running at 1080p resolution. You can use looking glass for the mouse/keyboard input and also bring up the guest display while on the host without having to switch between inputs on the monitor.