gpu passthrough question

[Jon W]

I am complete n00b and confused by what is meant by gpu passthrough and if I have set it correctly. Just installed Proxmox VE 8.2.2 and various online sources say in order to use gpu passthrough you would update the GRUB bootloader, blacklist drivers, edit kernel modules, etc.

I have not done any of that and it appears to work out of the box. What am I not understanding? Proxmox host is a fresh install on dell precision 3440 sff with xeon W-1250 cpu with virtualization enabled in the bios. Machine has iGPU and a discrete amd radeon pro wx 2100 gpu.

I created new debian 12 vm with default gnome desktop, bios is uefi, and cpu is host. Under hardware, I set display to none and clicked add pci device and as raw device I select the amd gpu. Works with either q35 or i440fx machine types, while some sources suggested q35 is required.

So my question is why does this just work when there are many tutorials saying I need to make various changes to the default proxmox host machine? Is what I have configured something different than what is meant by gpu passthrough? Thanks to anyone who can make this clearer for me.

 

[leesteken]

Your VM now has access to a real physcial PCI(e) device (i.e., your AMD GPU)? Then that's passthrough and everything is fine.
The most recent PVE kernels don't need intel_iommu=on anymore because it is not also enabled by default on Intel systems. Most other settings, early binding, blacklisting etc. are a work-around when things don't work out of the box. And with PCI(e) passthrough there are many, many possible issues and potential problems.
Most guides on the internet are also outdated and they all seem to copy each other and/or are very specific for a certain GPU but claim to be generic.

 

[Jon W]

Thanks for the super fast reply! Definitely like it when things just work, but was not expecting it so thought I must be missing something important since most of the guides I came across were taking me through a bunch of changes I should make. Thank you for the assurance.