error while running "rxe_cfg start" about rxe-dev HOT 2 CLOSED

The first message ('mkdir: ...') indicates the most likely problem. The script expects that configfs is mounted (this can be done manually with mount -t configfs none /sys/kernel/config assuming the kernel was built with appropriate support).
If the error still occurs, there might be some issue with permissions. You can try executing the same command as the script to see if the directory can be created at all: mkdir -p /sys/kernel/config/rdma_cm/rxe0.

The next message ('tee: ... No such file') should be resolved at the same time; this is caused by the script trying to write a value to the 'default_roce_mode' file in the device's configfs directory (you can run the same command manually with echo IBOE V2 | tee /sys/kernel/config/rdma_cm/$rxed/default_roce_mode).

The third message is unresolved to my knowledge, but is a minor issue. This is just an error in parsing the output text in ethtool (I assume this was originally compatible with an older version of the utility) that should not affect function.

If the issue persists, it might also help if you share the contents of /etc/udev/rules.d/10-local-ib.rules or any ib- or roce- related files in that directory.

from rxe-dev.

thanks for the solution, problem is solved by this script "mount -t configfs none /sys/kernel/config"

from rxe-dev.