Re: [dpdk-dev] [PATCH v2 1/6] net/af_xdp: introduce AF XDP PMD driver

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 19 Mar 2019 15:12:51 +0800
Xiaolong Ye <xiaolong.ye@intel.com> wrote:

> Add a new PMD driver for AF_XDP which is a proposed faster version of
> AF_PACKET interface in Linux. More info about AF_XDP, please refer to [1]
> [2].
> 
> This is the vanilla version PMD which just uses a raw buffer registered as
> the umem.
> 
> [1] https://fosdem.org/2018/schedule/event/af_xdp/
> [2] https://lwn.net/Articles/745934/
> 
> Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
> ---
>  MAINTAINERS                                   |   6 +
>  config/common_base                            |   5 +
>  config/common_linux                           |   1 +
>  doc/guides/nics/af_xdp.rst                    |  45 +
>  doc/guides/nics/features/af_xdp.ini           |  11 +
>  doc/guides/nics/index.rst                     |   1 +
>  doc/guides/rel_notes/release_19_05.rst        |   7 +
>  drivers/net/Makefile                          |   1 +
>  drivers/net/af_xdp/Makefile                   |  33 +
>  drivers/net/af_xdp/meson.build                |  21 +
>  drivers/net/af_xdp/rte_eth_af_xdp.c           | 930 ++++++++++++++++++
>  drivers/net/af_xdp/rte_pmd_af_xdp_version.map |   3 +
>  drivers/net/meson.build                       |   1 +
>  mk/rte.app.mk                                 |   1 +
>  14 files changed, 1066 insertions(+)
>  create mode 100644 doc/guides/nics/af_xdp.rst
>  create mode 100644 doc/guides/nics/features/af_xdp.ini
>  create mode 100644 drivers/net/af_xdp/Makefile
>  create mode 100644 drivers/net/af_xdp/meson.build
>  create mode 100644 drivers/net/af_xdp/rte_eth_af_xdp.c
>  create mode 100644 drivers/net/af_xdp/rte_pmd_af_xdp_version.map
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 452b8eb82..1cc54b439 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -468,6 +468,12 @@ M: John W. Linville <linville@tuxdriver.com>
>  F: drivers/net/af_packet/
>  F: doc/guides/nics/features/afpacket.ini
>  
> +Linux AF_XDP
> +M: Xiaolong Ye <xiaolong.ye@intel.com>
> +M: Qi Zhang <qi.z.zhang@intel.com>
> +F: drivers/net/af_xdp/
> +F: doc/guides/nics/features/af_xdp.rst
> +
>  Amazon ENA
>  M: Marcin Wojtas <mw@semihalf.com>
>  M: Michal Krawczyk <mk@semihalf.com>
> diff --git a/config/common_base b/config/common_base
> index 0b09a9348..4044de205 100644
> --- a/config/common_base
> +++ b/config/common_base
> @@ -416,6 +416,11 @@ CONFIG_RTE_LIBRTE_VMXNET3_DEBUG_TX_FREE=n
>  #
>  CONFIG_RTE_LIBRTE_PMD_AF_PACKET=n
>  
> +#
> +# Compile software PMD backed by AF_XDP sockets (Linux only)
> +#
> +CONFIG_RTE_LIBRTE_PMD_AF_XDP=n
> +
>  #
>  # Compile link bonding PMD library
>  #
> diff --git a/config/common_linux b/config/common_linux
> index 75334273d..0b1249da0 100644
> --- a/config/common_linux
> +++ b/config/common_linux
> @@ -19,6 +19,7 @@ CONFIG_RTE_LIBRTE_VHOST_POSTCOPY=n
>  CONFIG_RTE_LIBRTE_PMD_VHOST=y
>  CONFIG_RTE_LIBRTE_IFC_PMD=y
>  CONFIG_RTE_LIBRTE_PMD_AF_PACKET=y
> +CONFIG_RTE_LIBRTE_PMD_AF_XDP=y
>  CONFIG_RTE_LIBRTE_PMD_SOFTNIC=y
>  CONFIG_RTE_LIBRTE_PMD_TAP=y
>  CONFIG_RTE_LIBRTE_AVP_PMD=y
> diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst
> new file mode 100644
> index 000000000..dd5654dd1
> --- /dev/null
> +++ b/doc/guides/nics/af_xdp.rst
> @@ -0,0 +1,45 @@
> +..  SPDX-License-Identifier: BSD-3-Clause
> +    Copyright(c) 2018 Intel Corporation.
> +
> +AF_XDP Poll Mode Driver
> +==========================
> +
> +AF_XDP is an address family that is optimized for high performance
> +packet processing. AF_XDP sockets enable the possibility for XDP program to
> +redirect packets to a memory buffer in userspace.
> +
> +For the full details behind AF_XDP socket, you can refer to
> +`AF_XDP documentation in the Kernel
> +<https://www.kernel.org/doc/Documentation/networking/af_xdp.rst>`_.
> +
> +This Linux-specific PMD driver creates the AF_XDP socket and binds it to a
> +specific netdev queue, it allows a DPDK application to send and receive raw
> +packets through the socket which would bypass the kernel network stack.
> +Current implementation only supports single queue, multi-queues feature will
> +be added later.
> +
> +Options
> +-------
> +
> +The following options can be provided to set up an af_xdp port in DPDK.
> +
> +*   ``iface`` - name of the Kernel interface to attach to (required);
> +*   ``queue`` - netdev queue id (optional, default 0);
> +
> +Prerequisites
> +-------------
> +
> +This is a Linux-specific PMD, thus the following prerequisites apply:
> +
> +*  A Linux Kernel (version > 4.18) with XDP sockets configuration enabled;
> +*  libbpf (within kernel version > 5.1) with latest af_xdp support installed
> +*  A Kernel bound interface to attach to.
> +
> +Set up an af_xdp interface
> +-----------------------------
> +
> +The following example will set up an af_xdp interface in DPDK:
> +
> +.. code-block:: console
> +
> +    --vdev eth_af_xdp,iface=ens786f1,queue=0
> diff --git a/doc/guides/nics/features/af_xdp.ini b/doc/guides/nics/features/af_xdp.ini
> new file mode 100644
> index 000000000..7b8fcce00
> --- /dev/null
> +++ b/doc/guides/nics/features/af_xdp.ini
> @@ -0,0 +1,11 @@
> +;
> +; Supported features of the 'af_xdp' network poll mode driver.
> +;
> +; Refer to default.ini for the full list of available PMD features.
> +;
> +[Features]
> +Link status          = Y
> +MTU update           = Y
> +Promiscuous mode     = Y
> +Stats per queue      = Y
> +x86-64               = Y
> \ No newline at end of file


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