ConnectX-5 - Can't change VF's DSCP value of CNP from 0

We are evaluating RoCE communication using Pods with vRDMA devices on kubernetes.

To set priority of CNP to 6, we did below command but couldn’t get expected result.

We consider it would be limitation of VFs.

Did we have any misunderstanding or mistakes? (e.g. In fact it was not necessary.)

​command to set CNP’s DCSP value

echo 48 > /sys/class/net//ecn/roce_np/cnp_dscp

expected result

cat /sys/class/net//ecn/roce_np/cnp_dscp

48

actual result

cat /sys/class/net//ecn/roce_np/cnp_dscp

0

(Note: we got expected result from PF)

environment information

  • OS : Ubuntu18.04.1
  • K8S : 1.15.11
  • CNI : intel/sriov-cni
  • NIC : ConnectX-5 VPI
  • Driver : MLNX_OFED 5.0.1-0.0.0.0

Hi ,

Since you are using OFED 5.0 this command won’t work.

Please refer to the below

https://community.mellanox.com/s/article/howto-configure-dcqcn–roce-cc–values-for-connectx-4–linux-x

Thanks,

Samer