GPU Passthrough

Howdy all,

I'm primarily a Windows user (much to my own dismay) largely because I enjoy gaming and I also enjoy being able to use most applications available on the market. I've dabbled in Linux but have never been able to stay in that ecosystem because there's only so much you can do with WINE and even Proton.

So, the real issue is that we can install Linux and run Windows as a guest OS, but being on a laptop means we usually can't leverage the hardware we have to any great effect. Gaming on Linux has improved, but you can forget about mods, and there are still many titles that perform poorly or not at all.

But what if we could get the best of both worlds? Enter this bit of info I stumbled on:

https://forum.level1techs.com/t/how...ugh-on-notebooks-with-one-click-or-two/138687

This appears to be a way to get it all.

I'm going to give it a shot and see how it goes. Wish me luck!

 

Here's what I've figured out so far. Using VMWare Workstation Player 16 on Windows 10 Pro. You can open the guest OS using the discrete GPU to handle rendering. This is done by navigating to the executable for VMWare, right clicking it and selecting "Render with Open GL", which has a sub menu for selecting the GPU. Using Ubuntu, I ran some simple GPU benchmarks and discovered my AGA enclosed 1080ti was hamstrung, but ran better than the iGPU. I don't have anything to compare it to at present, but it is good to know that if you're using VMWare, you can leverage your dGPU to some degree.

I'm going to start with a fresh Fedora install on my Asus tomorrow and see if I can use the script mentioned in the link above. The author claims laptops with both an iGPU and dGPU can offload the dGPU to the guest OS and seamlessly take it back once the virtual machine is shut down. My only concern would be the number of cores lent to the guest. Probably not too big a deal with a hexacore or higher CPU, but the older four core processors might struggle.

 

Some things I'm figuring out:

• Only works with Fedora
• Only works with Nvidia dGPU
• CPU must have iGPU enabled (my G75VX didn't work)

Will report back with more findings soon.

 

I was gonna ask about your processor in your G75VX, is it VT-d capable at all? I thought GPU passthrough required that.

 

I recall running Vmware on it in the past, though it's been a while since I've done that. Isn't VT-d required for emulation too? I'm looking around for something I don't mind doing this on and I think my daily driver will have to do. Time to dual boot again...

 

Another update, Linux doesn't like that my Alienware is in RAID and will not install. I'm going to give this a shot from a live USB.

 

Any progress for you?

I've done with this with several Dell laptops (m6800 as well as my current 7730) but basically moved on. A couple of things I learned:

• Be prepared for driver issues with Nvidia. For a while, they had some hacks in their drivers to check if the GPU was being passed through and fail to initialize with a Code 43. There are miscellaneous hacks to work around it, but I did read that Nvidia may be allowing it again.
• It's tricky to get things working on your laptop screen. External monitors are much easier. There is some software you can use to stream from your VM onto your laptop, but it requires a couple CPU cores to really work well (or a Quadro card)
• Performance is actually quite good. GPU benchmarks were practically equivalent to bare metal. CPU suffered a little bit (10-15% that I could tell)
• Power management gets tricky. The VM won't know if you are on battery or not. The host will throttle accordingly, but the VM won't know about it. Things like Nvidia battery saver won't work anymore in the VM.
• Anti-cheat will cause large performance problems. It's better than Proton, where they mostly won't work if there is anti-cheat (like Denovo), but it will run slowly.

In the end, I just found it way easier to dual boot.

 

Bullet 1, yes, Nvidia is allowing GPU passthrough with their current drivers.

Bullet 2, the link I provided should work regardless of monitor configuration.

Bullet 3, I did use a live USB and couldn't get the files I needed to persist across reboots. When I used Windows as host and Linux guest with the dGPU (actually it was my GPU in the AGA) handling rendering for the guest, I noted almost zero loss in performance when compared to a bare metal install. My hope would be the reverse should reflect similar performance

Bullet 4, Not concerned about power management, though I can understand others might be

Bullet 5, yes, anti-cheat is a problem for GPU-passthrough solutions

With Win11 on the horizon, and how crappy it looks like it will be, I think it being in a VM is preferable to dual booting.

 

for bullet 2 look in to Looking Glass software, apologies for grave digging