when using write op with more than 1024B(MTU)，the operation fail

when write message length is more than 1024B(mtu), it failed in softroce mode, pls help check why.

using the standard tool ib_write_lat to test: when ib_write_lat -s 1024 -n 5 when ib_write_lat -s 1025 -n 5, it fail.

my softroce version in in "Red Hat Enterprise Linux Server release 7.4 (Maipo)"

Is it a bug in softroce? Thanks!