Configuring IOMMU

[carsten12]

Dear all,

I tried to enable IOMMU for PCI-Passthrough. I tried with three different machines, all of them now crispy fresh. Nevertheless as I had the same result

• IOMMU not working, there are no IOMMU device groups, popup complains
• but no real error found in dimes, in fact it is the absence of DMAR messages

As I tried so many things, let me assure that at least I

• switched on virtualization, but all boards only have that and don't distinguish between VT-x and VT-d
• am on grub and added intel_iommu=on in /etc/default/grub and it made it into the log and /proc/cmdline
• added the modules in /etc/modules
• also tried combinations of iommu=on, iommu=pt, allow_unsafe_assigned_interrupts=1

Being curious whether the absence on *any* other DMAR message is showing that the board/cpu is not supporting VT-d I checked
with in total three boards and CPUs but it is the same picture in all cases, so I wanted to ask whether maybe I made a general mistake.

The combos are:

• Asrock P5B-DE with E5700 which is clearly not working (CPU doesn't support VT-d)
• Intel DH67CL with i5-2600T with latest 2018 BIOS
• Gigabyte GA-Z68MX-UD2H-B3 with i7 2700K and latest UEFI BIOS

So does anybody know a secret switch or are these combos simply too old? What do you think?

Best Regards,
Carsten.