No interrupt remapping support

Afox

Renowned Member
Dec 18, 2014
257
13
83
Hello,

I try to enable SR-IOV and mostly used 3 sources for this: 1 2 3

When I add a VF-PCi(e)-device to a KVM, it won´t start due to this error:
failed to setup container for group xx: Failed to set iommu for container: Operation not permitted

What I did:

Add required modules
Enable iommu within grub
Enable creation of VF via modprobe (max_vfs)
Blacklist VF driver

VFs are showing up (lspci -vv | grep Eth) and each VF is getting its own iommu_group (find /sys/kernel/iommu_groups/ -type l).

VF numbering is as follows (Dual Port, 6 VFs per Port):
06:10.0
06:10.1
06:10.2
06:10.3
06:10.4
06:10.5
06:10.6
06:10.7
06:11.0
06:11.1
06:11.2
06:11.3
When I try to check if IOMMU is enabled (dmesg | grep -e DMAR -e IOMMU -e AMD-Vi) I get the following:
vfio_iommu_type1_attach_group: No interrupt remapping support. Use the module param "allow_unsafe_interrupts" to enable VFIO IOMMU support on this platform

This confuses me because my ecap value (dmesg | grep ecap) has an "e" at the end which (regarding this source) means that interrupt remapping should be supported.

I tried enabling the suggested unsafe interrupts and it worked.

Nevertheless I want to ask if there is anything I can do to get it working without unsafe interrupts.

Additional info: the NIC is seated in a riser that provides 2 times x8 slots (Slot 2 and 4). I put it in Slot 4 for thermal reasons. Slot 2 is empty.

Regards,

Afox
 
Last edited:
i most cases i encountered, this is actually a limitation of the used hardware (especially the mainboard) and can only be 'fixed' with either an
updated bios or another mainboard

what can also work is to put it in a different slot and/or tweaking the bios settings for passthrough