I have installed MLNX_OFED_LINUX-3.4- after installation of MLNX OFED stack in the  /lib/modules/4.8.7perry/extra/ directory it contains fallowing folders.

iser  kernel-mft  knem  mlnx-nvme-rdma  mlnx-nvmet-rdma  mlnx-ofa_kernel  mlnx-rds  mlnx-sdp  srp

[root@xhd-ipsspdk1 mlnx-nvme-rdma]# modinfo nvme-rdma.ko

filename:       /lib/modules/4.8.7perry/extra/mlnx-nvme-rdma/nvme-rdma.ko

license:        GPL v2

srcversion:     7D6C6F6F641C78226E9C4B2

depends:        mlx_compat,ib_core,nvme-fabrics,nvme-core,rdma_cm

vermagic:       4.8.7perry SMP mod_unload modversions

parm:           register_always:Use memory registration even for contiguous memory regions (bool)


But if I install another MLNX_OFED_LINUX-4.1- . I did not find mlnx-nvme-rdma folder. if I give modinfo nvme-rdma.ko  it is showing dummy driver.

[root@xhd-ipsnvmeof1 extra]# pwd


[root@xhd-ipsnvmeof1 extra]# ls

iser  isert  kernel-mft  knem  mlnx-ofa_kernel  srp

[root@xhd-ipsnvmeof1 extra]#

[root@xhd-ipsnvmeof1 extra]# modinfo nvme-rdma

filename:       /lib/modules/4.8.7perry/extra/mlnx-ofa_kernel/drivers/nvme/host/nvme-rdma.ko

version:        2.0.0

license:        Dual BSD/GPL

description:    nvme-rdma dummy kernel module

author:         Alaa Hleihel

srcversion:     0327CA0FFF5D3C86AF11657

depends:        mlx_compat

vermagic:       4.8.7perry SMP mod_unload modversions

[root@xhd-ipsnvmeof1 extra]#

why few MLNX OFED stacks will give dummy rdma drivers, what is reason for this ?