.. SPDX-License-Identifier: BSD-3-Clause
- Copyright(c) 2019 Intel Corporation.
+ Copyright(c) 2019-2020 Intel Corporation.
AF_XDP Poll Mode Driver
==========================
* ``iface`` - name of the Kernel interface to attach to (required);
* ``start_queue`` - starting netdev queue id (optional, default 0);
* ``queue_count`` - total netdev queue number (optional, default 1);
+* ``shared_umem`` - PMD will attempt to share UMEM with others (optional,
+ default 0);
+* ``xdp_prog`` - path to custom xdp program (optional, default none);
Prerequisites
-------------
* A Kernel bound interface to attach to;
* For need_wakeup feature, it requires kernel version later than v5.3-rc1;
* For PMD zero copy, it requires kernel version later than v5.4-rc1;
+* For shared_umem, it requires kernel version v5.10 or later and libbpf version
+ v0.2.0 or later.
Set up an af_xdp interface
-----------------------------
Note: The AF_XDP PMD will fail to initialise if an MTU which violates the driver's
conditions as above is set prior to launching the application.
+
+- **Shared UMEM**
+
+ The sharing of UMEM is only supported for AF_XDP sockets with unique contexts.
+ The context refers to the netdev,qid tuple.
+
+ The following combination will fail:
+
+ .. code-block:: console
+
+ --vdev net_af_xdp0,iface=ens786f1,shared_umem=1 \
+ --vdev net_af_xdp1,iface=ens786f1,shared_umem=1 \
+
+ Either of the following however is permitted since either the netdev or qid differs
+ between the two vdevs:
+
+ .. code-block:: console
+
+ --vdev net_af_xdp0,iface=ens786f1,shared_umem=1 \
+ --vdev net_af_xdp1,iface=ens786f1,start_queue=1,shared_umem=1 \
+
+ .. code-block:: console
+
+ --vdev net_af_xdp0,iface=ens786f1,shared_umem=1 \
+ --vdev net_af_xdp1,iface=ens786f2,shared_umem=1 \
\ No newline at end of file