10GB network + pci passthrough = DMFS high rate mode not supported

[Christoffer Jönsson]

Hello! I want to enable my VM with 10GB network.
So I followed the Proxmox guide for passthrough, installed the latest CentOS and the drivers for the Mellanox ConnectX-2.

Rebooted the VM and was greeted with this message:

Does anyone know what this error means?
Motherboard is SuperMicro X8DTL-iF

Spoiler: IOMMU isolation

root@vmhost-gluster05:~# lspci | grep '3:00.0'
03:00.0 Ethernet controller: Mellanox Technologies MT26448 [ConnectX EN 10GigE, PCIe 2.0 5GT/s] (rev b0)
root@vmhost-gluster05:~# find /sys/kernel/iommu_groups/ -type l | grep '03:00.0'
/sys/kernel/iommu_groups/13/devices/0000:03:00.0
root@vmhost-gluster05:~# lspci -n -s 03:00.0
03:00.0 0200: 15b3:6750 (rev b0)

On VM:
root@gluster05:~# lspci | grep '1:00.0'
01:00.0 Ethernet controller: Mellanox Technologies MT26448 [ConnectX EN 10GigE, PCIe 2.0 5GT/s] (rev b0)

Thanks!

 

[Alwin]

DMFS - Device Managed Flow Steering, the card might just not support it. You may be able to load the kernel module with disabled DMFS, but if you need that feature, then you may need to upgrade the NIC.