BlueField-3 Jumbo MTU Not Working

Ping failed with packet size greater than 1500/4000 after configuring jumbo MTU.

Jumbo MTU is supported starting from the following kernel version:

The following steps configure jumbo MTU:

1. Change the MTU of uplink representor (or bond) from the BlueField Arm OS:

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   # echo 9216 > /sys/bus/pci/devices/0000:03:00.0/net/p0/mtu
           

2. Restart virtio-net-controller from the BlueField Arm OS:

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   # systemctl restart virtio-net-controlle
           

3. Change the corresponding device MTU on BlueField Arm OS. For example, for the first VF on the first PF, run:

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   # virtnet modify -p 0 -v 0 device -t 9216
           

4. Reload the virtio driver from the guest OS:

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   # modprobe -rv virtio-net && modprobe -v virtio-net
           

5. Verify the VQs’ MTU configuration is correct on BlueField Arm OS:

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   # virtnet query -p 0 -v 0 --dbg_stats | grep jumbo_mtu
       "jumbo_mtu": 1
       "jumbo_mtu": 1
           

6. Change the MTU of the virtio-net interface from the guest OS:

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   # echo 9216 > /sys/bus/pci/devices/0000:af:00.2/virtio0/net/enp175s0f2/mtu