# RDMA (ibverb) Ethernet driver {#rdma_doc}

This driver relies on Linux rdma-core (libibverb) userspace poll-mode driver
to rx/tx Ethernet packets. Despite using the RDMA APIs, this is **not** about
RDMA (no Infiniband, no RoCE, no iWARP), just pure traditional Ethernet
packets.

## Maturity level
Under development: it should work, but has not been thoroughly tested.

## Supported Hardware
 - Mellanox ConnectX-4
 - Mellanox ConnectX-5

## Features
 - bifurcation: MAC based flow steering for transparent sharing of a single
physical port between multiple virtual interfaces including Linux netdev
 - multiqueue

## Security considerations
When creating a rdma interface, it will receive all packets to the MAC address
attributed to the interface plus a copy of all broadcast and multicast
traffic.
The MAC address is under the control of VPP: **the user controlling VPP can
divert all traffic of any MAC address to the VPP process, including the Linux
netdev MAC address as long as it can create a rdma interface**.
The rights to create a rdma interface are controlled by the access rights of
the `/dev/infiniband/uverbs[0-9]+`device nodes.

## Quickstart
1. Make sure the `ib_uverbs` module is loaded:
```
~# modprobe ib_uverbs
```
2. In VPP, create a new rdma virtual interface tied to the Linux netdev of the
physical port you want to use (`enp94s0f0` in this example):
```
vpp# create int rdma host-if enp94s0f0 name rdma-0
```
3. Use the interface as usual, eg.:
```
vpp# set int ip addr rdma-0 1.1.1.1/24
vpp# set int st rdma-0 up
vpp# ping 1.1.1.100`
```

### Containers support
It should work in containers as long as:
 - the `ib_uverbs` module is loaded
 - the device nodes `/dev/infiniband/uverbs[0-9]+` are usable from the
   container (but see [security considerations](#Security considerations))