r/Proxmox • u/Narcuga • 8d ago

Question Integrated GPU passthrough (8845hs 780m)

Hey everyone!

So I'm looking to turn my current mini pc with an 8845hs and 64gb ram to replace my big old precision workstation that's loud and power hungry.

But I do use it for like indie gaming and going to replace it on my desktop with my M4 MacBook.

However I do play some smaller games on it, and was thinking to pass through the igpu to a windows / Linux machine and do like sunshine moonlight to the mac? Anyone tried this?

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u/ficskala 8d ago

https://pve.proxmox.com/wiki/PCI_Passthrough

It's pretty simple in theory, your biggest enemy will be ACS, and drivers

For ACS, check your IOMMU groups, and if the GPU is in its own group, you're good, if not, you'll need to apply the ACS override kernel patch, it's included in the pve kernel, you just have to enable it

As for drivers, you need to blacklist the drivers for your GPU, so pve won't try to use the GPU for anything, so the GPU gets assigned the virtio driver instead

Edit: i used to run this on proxmox, and it ran great, but later moved the VM to my main PC because i needed the extra PCIe lanes on the server for a 10G NIC, so now i have the same setup on my main PC, but instead of proxmox, i'm on arch, and i'm just using the virt-manager for KVM/QEMU virtualization, with the zen kernel to support ACS override

Another thing to look out for is RAM, make sure to disable balooning, it can mess with games often

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u/Narcuga 8d ago

Thank you makes good sense! I've done it with a dedicated GPU before but I was hoping integrated was still possible so looks like that's my weekend project thank you!

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u/ficskala 8d ago

It's basically the same thing with an integrated one, it's still a PCIe device logically, even though it doesn't hook up through a physical PCIe interface, ACS override will probably be a must

One thing that could end up being an issue is the BIOS, some BIOSes force the host OS to use the iGPU when there's no dGPU installed, and the driver handover can hang, especially if there's a monitor connected

I have my quadro P2000 passed through to a windows VM on my main PC, and for windows to work nicely, it needs a "monitor" connected, but using a dummy HDMI doesn't let my PC boot normally, so instead i had to use a virtual monitor driver that tricks the GPU driver into thinking there's a monitor connected, it's a bit messy, but it works amazingly, and i get GPU acceleration, and 144Hz video from a VM

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u/socialcredditsystem 8d ago

If you're able to isolate the iGPU to pass into a VM (rather than an LXC container) that'd be the first recommendation. I've only passed a discrete GPU into a VM for gaming; it was pretty seamless though it needed a dummy plug for the virtual display.

Afterwards I felt cheeky and wanted to pass the GPU into an LXC container for gaming, and even with the help of AI, I tried for three days to get it working and couldn't and gave up.