"find /sys/kernel/iommu_groups/ -type l" does not yield anything


New Member
Dec 14, 2019

I am stuck with PCIe Passthrough. I would appreciate every bit of help.

My system setup is:
CPU: 2x Intel Xeon E5-2680
MB: ASRock EP2C602-4L/D16
OS: PRoxmox VE 6.0 in UEFI

As far as I know the Hardware supports PCIe Passthrough.

I followed this guide: https://pve.proxmox.com/wiki/PCI(e)_Passthrough

I enabled VT / VT-d Support in the UEFI Setup
modified "/etc/kernel/cmdline" with "intel_iommu=on" in a new line
ran "pve-efiboot-tool refresh"
added all modules listed in the guide to "/etc/modules"
ran "update-initramfs -u -k all"

Now the Part where I am stuck:
ran "find /sys/kernel/iommu_groups/ -type l" and i got no output
The Webinterface states "no iommu detected"

If anyone has an idea what the problem is I would appreciate a response. Thanks in advance.
what does 'cat /proc/cmdline' show ?
I have read that guide and applied it. The only problem: if I write following in /etc/kernel/cmdline :
root=ZFS=rpool/ROOT/pve-1 boot=zfs intel_iommu=on
Proxmox won`t boot anymore. Only into initramfs

I tried it with grub, but that didn't have any effect. cat /proc/cmdline showed:
initrd=\EFI\proxmox\5.3.10-1-pve\initrd.img-5.3.10-1-pve root=ZFS=rpool/ROOT/pve-1 boot=zfs
Last edited:
Did you run "pve-efiboot-tool refresh" after adding the entry into /etc/kernel/cmdline and re-boot? I was having the same issue as you with nothing listed in the /sys/kernel/iommu_groups directory until I did this.


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