Dual Port NIC Passthrough Issue

cwingert

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Feb 28, 2021
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I am trying to pass a PCIe NIC with two ports through to a VM of Ubuntu 20.10.1 and the second port is not coming up.

I have tried adding "All Functions" and also tried adding the PCI Functions separately.

Both yield the result "igb: probe of xxxxxxx failed with error -13"
 

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Did you tried it with a single entry "02:00" instead of "02:00.0" + "02:00.1"? That could help if your NIC, mainboard or CPU isn't able to use different IOMMU groups for single functions of a PCIe device (like if your CPU only supports VT-d but not VT-x).
 
Did you tried it with a single entry "02:00" instead of "02:00.0" + "02:00.1"? That could help if your NIC, mainboard or CPU isn't able to use different IOMMU groups for single functions of a PCIe device (like if your CPU only supports VT-d but not VT-x).
Thanks for your response. Tried both ways of adding the card (all functions and individual functions).
 
So this actually turned out to be an issue with the NIC itself. The hardware for the second port seems to hang once it is passed through to a guest OS. Even Proxmox (after a warm boot) showed the same error when initializing the second port on the NIC. The only way to get the second port out of that state was a cold boot or reset.

Passing through port 1 of the card and the motherboard NIC worked fine.

In addition, I picked up a NC365T on eBay and all 4 ports passed through just fine.

Thanks for your help!