CONFIG_INFINIBAND_ERDMA is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

Alibaba Elastic RDMA Adapter (ERDMA) support

modulename: erdma.ko

configname: CONFIG_INFINIBAND_ERDMA

Linux Kernel Configuration
└─>Device Drivers
└─>InfiniBand support
└─>Alibaba Elastic RDMA Adapter (ERDMA) support
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
This is a RDMA/iWarp driver for Alibaba Elastic RDMA Adapter(ERDMA),
which supports RDMA features in Alibaba cloud environment.

To compile this driver as module, choose M here. The module will be
called erdma.

source code: