There’s no need for adding all of those flags to your kernel command line - just the ones below will do the job:

intel_iommu=on iommu=pt video=efifb:off modprobe.blacklist=snd_hda_intel,snd_hda_codec_hdmi,i915

OP just needs to be aware that turning off the EFI framebuffer as above will result in no video output for the Proxmox host.

If you need further IOMMU group separation and your motherboard doesn’t support ACS, then you can add:

pcie_acs_override=downstream

If you run into problems with booting Proxmox, then you can simply remove the lines above at boot and then troubleshoot after.

So this definitely seems like the guide that helped the most. I spent more hours than I would like to admit working on this over this weekend.

I am trying to figure out if I have a way to do what I want to here. When it was all said and done I could no longer log into the remote computer I was using to run my Jellyfin server. I have been messing around a little bit using a Linux PC with that, and enjoyed that aspect of things, but it seems like once you get hardware acceleration going, you cannot see the desktop anymore. There were several warnings about this so I wasn't entirely surprised when it happened.

I think I am going to end up needing to get rid of the proxmox part, and just run Linux directly on the computer if I want to do this, and remote into it. It is currently not hooked up to a monitor and is actually on top of my kitchen cabinets out of the way. It was a fun challenge and I learned a lot I think.

second to this, and to add on that while it's gotten easier (and yes, even with this guide, it's much easier than it used to be) back up your system. Hopefully nothing goes wrong, but you are messing with the kernel, make sure you're mentally prepared to have to build it all from the ground up.

Thanks for this! Looking forward to trying it out!