SMB Direct – SMB3 over RDMA — The Linux Kernel documentation

Install an RDMA device. As long as the RDMA device driver is supported
by the kernel, it should work. This includes both software emulators (soft
RoCE, soft iWARP) and hardware devices (InfiniBand, RoCE, iWARP).

Install a kernel with SMB Direct support. The first kernel release to
support SMB Direct on both the client and server side is 5.15. Therefore,
a distribution compatible with kernel 5.15 or later is required.

Install cifs-utils, which provides the mount.cifs command to mount SMB
shares.

Configure the RDMA stack

Make sure that your kernel configuration has RDMA support enabled. Under
Device Drivers -> Infiniband support, update the kernel configuration to
enable Infiniband support.

Enable the appropriate IB HCA support or iWARP adapter support,
depending on your hardware.

If you are using InfiniBand, enable IP-over-InfiniBand support.

For soft RDMA, enable either the soft iWARP (RDMA _SIW) or soft RoCE
(RDMA_RXE) module. Install the iproute2 package and use the
rdma link add command to load the module and create an
RDMA interface.

e.g. if your local ethernet interface is eth0, you can use:

sudo rdma link add siw0 type siw netdev eth0

Enable SMB Direct support for both the server and the client in the kernel
configuration.

Server Setup

Network File Systems  --->
     SMB3 server support
        [*] Support for SMB Direct protocol

Client Setup

Network File Systems  --->
     SMB3 and CIFS support (advanced network filesystem)
        [*] SMB Direct support

Build and install the kernel. SMB Direct support will be enabled in the
cifs.ko and ksmbd.ko modules.