It seems SQSIZE in linux-nvmf is by default set to 128 and seems to be 127 in the NVMf code, but I think the RDMA driver does a +1 to it? This causes SPDK to not accept the cmd.

https://github.com/spdk/spdk/commit/a5be12c376f42108085bd9cfd06fc27818fdb6c9

I suggest either changing this to ">" instead of ">=" or changing the nvmf.conf.in MaxQueueDepth size to 129 by default.

Here's the error msg:
***ERROR*** Invalid SQSIZE 128 (min 1, max 127)