PCI Passthrough - Not Capable

[ckirsten]

Hello all,

I have an old proprietary PCI card that I need to passthrough to a Windows VM. I was able to test this out on a 7th gen Intel HP Z240, and it worked perfectly using ESXi v8.

I purchased an Intel i7-12700 HP Z2 G9 desktop, and after getting past the P/E core issue by adding the CPU panic check line, the PCI card is now listed as "not capable" in the passthrough column. VT-D is enabled in the BIOS.

The PCI card is actually a PCI card, not a PCIe card. It's connected via an external box that is connected via a cable going to a PCIe card in the host. I don't think this is the issue, as it was connected like this on the 7th gen system.

Any thoughts on what I can do to get the PCI card attached to the VM on this hardware, or perhaps what my limiting factor is here?

Thanks!

[ckirsten]

I should also note that other devices that I seem to be able to set as passthrough, including an expansion Intel network card. See screenshot for what's present.

What exactly defines what can and cannot be set as passthrough?

[ckirsten]

Update:

I was able to resolve this issue. When I switched from test hardware to new hardware I also changed the model of external PCI enclosure from This to This. When I put the old enclosure on the new desktop PC, I was able to select the device to pass through.

The primary difference between the two is the size...I have a 30cm PCI card, which won't fit in the small one. Apparently there is also some other technical difference which does not seem to be compatible with VT-D for some reason. The larger one does have two PCIe slots instead of just 4 PCI slots.

I'd still be curious to learn what exactly defines what can and cannot be passed through like we need to do here. For this purpose, I'm going to either need to buy a small and a large enclosure to swap the boards so that I can get the PCI card enclosed, or have a larger case fabricated.

Thanks all