For info: lost IOMMU on upgrade and how I fixed it.

[orangehand]

I am running PVE on one of the little Chinese quad 2.5 NIC N5105 boxes featured by Serve the Home. I had successfully migrated my APU24 pfSense to this box as a vm. Install ISO was from 2 days ago. I then checked for updates. The GUI method failed to install 44 of the packages available. I brought it up to date earlier today via cmd line: apt update and apt full-upgrade. On reboot my pfSense wouldn't start as it couldn't find IOMMU. I had to manually amend /etc/default/grub adding in intel_iommu=on after quiet then grub-update and rebooting.

I have no idea why this happened but I hope this helps someone.

My /etc/modules file is empty - does it need values in it like:
vfio
vfio_iommu_type1
vfio_pci
vfio_virqfd

?

 

[Stoiko Ivanov]

Install ISO was from 2 days ago. I

I brought it up to date earlier today via cmd line: apt update and apt full-upgrade.

yes - the kernel shipped with the ISO has intel_iommu on per default - since this caused some issues in certain hardware setups it was reverted back to bein off per default (you can always explicitly set it to on or off of course - and if you rely on it I'd suggest to do so)

see also: https://pve.proxmox.com/wiki/Roadmap#7.2-known-issues


I hope this explains it.