Short remider to myself and the rest of the world:
- Upgrade Firmware to latest (yes, 2013 is better than 2011)
- Set UEFI to UEFI ONLY! It’s 2021 as of now, so nobody should be using BIOS anymore. Seriously.
- Boot Kernel with iommu=soft option (in grub press „e“ if you are locked out already)
- Put iommu=soft boot option to /etc/default/grub (GRUB_CMDLINE_LINUX_DEFAULT) and do a update_grub && reboot to make it a permanent fix
- If running AMD + Proxmox, use amd_iommu=on iommu=pt
- If running INTEL + Proxmox, use intel_iommu=on iommu=pt