PCI Passthrough - Wifi 6 AX200 is not recognized

mazhar555

New Member
Aug 18, 2023
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0
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Hello,
System:
MB: B550i Asus Rog Strix
CPU: Risen 5 5600G

I am brand new to Proxmox, with the help of YouTube and Proxmox documentation, I am able to install Proxmox VE. I am facing difficulty to add Wifi 6 AX200 as a PCI device in my Ubuntu VM. As soon as I add it, run the VM, my Procmox got stuck and then I have to restart the whole system. I have mentioned all the IOMMU settings and PCI device configuration in the attached images for better understanding.

I would be greatfull if anyone can help me out. Since I am new, you have to guide me step by step.


Thanks!
M
 

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From screenshot 2 you can see that the device is in IOMMU group 8. But also a lot of other devices are in group 8. IOMMU groups cannot (for security isolation reasons) be shared between VMs and/or the Proxmox host. When you start the VM, the Proxmox host also be disconnected of all the other devices in group 8 and probably lose it's network connection and disk drives, makeing it freeze or crash.
The big "chipset" IOMMU group is common to all Ryzen motherboards except X570(S). Only the first x16 PCIe slot (and on X370 and X470 the second x16, when not using an APU) and the first M.2 slot are in separate IOMMU group. As are some of the devices that come directly from the CPU. Try putting your WiFi 6 AX200 device in the first x16 slot.
Lots of threads on this forum about AM4 motherboards and IOMMU groups...
 
From screenshot 2 you can see that the device is in IOMMU group 8. But also a lot of other devices are in group 8. IOMMU groups cannot (for security isolation reasons) be shared between VMs and/or the Proxmox host. When you start the VM, the Proxmox host also be disconnected of all the other devices in group 8 and probably lose it's network connection and disk drives, makeing it freeze or crash.
The big "chipset" IOMMU group is common to all Ryzen motherboards except X570(S). Only the first x16 PCIe slot (and on X370 and X470 the second x16, when not using an APU) and the first M.2 slot are in separate IOMMU group. As are some of the devices that come directly from the CPU. Try putting your WiFi 6 AX200 device in the first x16 slot.
Lots of threads on this forum about AM4 motherboards and IOMMU groups...
Hello, Thanks for quick reply.

I have the same doubt but i am using B550i (Mini ITX) with only 1 PCI 16x slot, which is empty. The wifi 6 card is built it, i cant move it physically to any other slot. I don't know how to isolate it from group 8.

Thanks,
M
 
I have the same doubt but i am using B550i (Mini ITX) with only 1 PCI 16x slot, which is empty. The wifi 6 card is built it, i cant move it physically to any other slot. I don't know how to isolate it from group 8.
Then you cannot properly isolate it. The IOMMU groups are determined by the motherboard physical PCIe layout and chips. This is a very common problem that people discover (on this forum) after buying hardware. Maybe exchange the motherboard for one that is better suited for PCIe passthrough?
If you don't care that the VM can read (and write) all of the Proxmox host memory, and steal your passwords from Proxmox and other VMs, then you could search (this forum) for pcie_acs_override.
 
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