[dpdk-dev] [PATCH v6] doc: introduce openwrt how-to guide

Ray Kinsella mdr at ashroe.eu
Mon Feb 17 16:08:34 CET 2020


On 17/02/2020 02:47, Xiaolong Ye wrote:
> This doc describes how to enable DPDK on Openwrt in both virtual and
> physical x86 environment.
> 
> Signed-off-by: Xiaolong Ye <xiaolong.ye at intel.com>
> Acked-by: John McNamara <john.mcnamara at intel.com>
> ---
> 
> V6 changes:
> 
> 1. addressed review comments raised by Thomas
> 
> V5 changes:
> 
> 1. improve the doc's grammar and wording according to John's
> suggestions.
> 
> V4 changes:
> 
> 1. add release notes
> 
> V3 changes:
> 
> 1. emphasize target select in `OpenWrt configuration` section
> 
> V2 changes:
> 
> 1. add meson build steps for dpdk
> 2. replace steps about build openwrt and running dpdk application with
> links
> 
> 
>  doc/guides/howto/index.rst             |   1 +
>  doc/guides/howto/openwrt.rst           | 163 +++++++++++++++++++++++++
>  doc/guides/rel_notes/release_20_02.rst |   5 +
>  3 files changed, 169 insertions(+)
>  create mode 100644 doc/guides/howto/openwrt.rst
> 
> diff --git a/doc/guides/howto/index.rst b/doc/guides/howto/index.rst
> index a4c131652..5a97ea508 100644
> --- a/doc/guides/howto/index.rst
> +++ b/doc/guides/howto/index.rst
> @@ -19,3 +19,4 @@ HowTo Guides
>      packet_capture_framework
>      telemetry
>      debug_troubleshoot
> +    openwrt
> diff --git a/doc/guides/howto/openwrt.rst b/doc/guides/howto/openwrt.rst
> new file mode 100644
> index 000000000..6081f057b
> --- /dev/null
> +++ b/doc/guides/howto/openwrt.rst
> @@ -0,0 +1,163 @@
> +..  SPDX-License-Identifier: BSD-3-Clause
> +    Copyright(c) 2019 Intel Corporation.
> +
> +Enable DPDK on OpenWrt
> +======================
> +
> +This document describes how to enable Data Plane Development Kit (DPDK) on
> +OpenWrt in both a virtual and physical x86 environment.
> +
> +Introduction
> +------------
> +
> +The OpenWrt project is a well-known source-based router OS which provides a
> +fully writable filesystem with package management.
> +
> +Build OpenWrt
> +-------------
> +
> +You can obtain OpenWrt image through https://downloads.openwrt.org/releases.
> +To fully customize your own OpenWrt, it is highly recommended to build it from
> +the source code. You can clone the OpenWrt source code as follows:
> +
> +.. code-block:: console
> +
> +    git clone https://git.openwrt.org/openwrt/openwrt.git
> +
> +OpenWrt configuration
> +~~~~~~~~~~~~~~~~~~~~~
> +
> +* Select ``x86`` in ``Target System``
> +* Select ``x86_64`` in ``Subtarget``
> +* Select ``Build the OpenWrt SDK`` for cross-compilation environment
> +* Select ``Use glibc`` in ``Advanced configuration options (for developers)``
> +  then ``ToolChain Options`` and ``C Library implementation``
> +
> +Kernel configuration
> +~~~~~~~~~~~~~~~~~~~~
> +
> +The following configurations should be enabled:
> +
> +* ``CONFIG_VFIO_IOMMU_TYPE1=y``
> +* ``CONFIG_VFIO_VIRQFD=y``
> +* ``CONFIG_VFIO=y``
> +* ``CONFIG_VFIO_NOIOMMU=y``
> +* ``CONFIG_VFIO_PCI=y``
> +* ``CONFIG_VFIO_PCI_MMAP=y``
> +* ``CONFIG_HUGETLBFS=y``
> +* ``CONFIG_HUGETLB_PAGE=y``
> +* ``CONFIG_PROC_PAGE_MONITOR=y``
> +

My 2c is that this is only ok as a short term solution.
However we really ought to be aiming for upstream support in OpenWRT, right?

For instance, why would enabling VFIO in OpenWRT necessitate a kernel rebuild.
We have had Intel IOMMU's for more than 10 years, why wouldn't this be enabled by default?
I imagine hugepages have been around a similar period.

> +Build steps
> +~~~~~~~~~~~
> +
> +For detailed OpenWrt build steps and prerequisites, please refer to the
> +`OpenWrt build guide
> +<https://openwrt.org/docs/guide-developer/build-system/use-buildsystem>`_.
> +
> +After the build is completed, you can find the images and SDK in
> +``<OpenWrt Root>/bin/targets/x86/64-glibc/``.
> +
> +
> +DPDK Cross Compilation for OpenWrt
> +----------------------------------

> +Pre-requisites
> +~~~~~~~~~~~~~~
> +
> +NUMA is required to run DPDK in x86.
> +
> +.. note::
> +
> +    For compiling the NUMA lib, run ``libtool --version`` to ensure the libtool
> +    version >= 2.2, otherwise the compilation will fail with errors.
> +
> +.. code-block:: console
> +
> +    git clone https://github.com/numactl/numactl.git
> +    cd numactl
> +    git checkout v2.0.13 -b v2.0.13
> +    ./autogen.sh
> +    autoconf -i
> +    export PATH=<OpenWrt SDK>/glibc/openwrt-sdk-x86-64_gcc-8.3.0_glibc.Linux-x86_64/staging_dir/toolchain-x86_64_gcc-8.3.0_glibc/bin/:$PATH
> +    ./configure CC=x86_64-openwrt-linux-gnu-gcc --prefix=<OpenWrt SDK toolchain dir>
> +    make install
> +
> +The numa header files and lib file is generated in the include and lib folder
> +respectively under <OpenWrt SDK toolchain dir>.

Why not an upstream numactl package in OpenWRT,
that just installs the shared libraries and development headers instead of these gymnastics? 

> +Build DPDK
> +~~~~~~~~~~
> +
> +To cross compile with meson build, you need to write a customized cross file
> +first.
> +
> +.. code-block:: console
> +
> +    [binaries]
> +    c = 'x86_64-openwrt-linux-gcc'
> +    cpp = 'x86_64-openwrt-linux-cpp'
> +    ar = 'x86_64-openwrt-linux-ar'
> +    strip = 'x86_64-openwrt-linux-strip'
> +
> +    meson builddir --cross-file openwrt-cross
> +    ninja -C builddir
> +
> +.. note::
> +
> +    For compiling the igb_uio with the kernel version used in target machine,
> +    you need to explicitly specify kernel_dir in meson_options.txt.

As above, why not have an upstream DPDK package in OpenWRT,
that just installs the shared libraries and development headers instead of these gymnastics? 

> +Running DPDK application on OpenWrt
> +-----------------------------------
> +
> +Virtual machine
> +~~~~~~~~~~~~~~~
> +
> +* Extract the boot image
> +
> +.. code-block:: console
> +
> +    gzip -d openwrt-x86-64-combined-ext4.img.gz
> +
> +* Launch Qemu
> +
> +.. code-block:: console
> +
> +    qemu-system-x86_64 \
> +            -cpu host \
> +            -smp 8 \
> +            -enable-kvm \
> +            -M q35 \
> +            -m 2048M \
> +            -object memory-backend-file,id=mem,size=2048M,mem-path=/tmp/hugepages,share=on \
> +            -drive file=<Your OpenWrt images folder>/openwrt-x86-64-combined-ext4.img,id=d0,if=none,bus=0,unit=0 \
> +            -device ide-hd,drive=d0,bus=ide.0 \
> +            -net nic,vlan=0 \
> +            -net nic,vlan=1 \
> +            -net user,vlan=1 \
> +            -display none \
> +
> +
> +Physical machine
> +~~~~~~~~~~~~~~~~
> +
> +You can use the ``dd`` tool to write the OpenWrt image to the drive you
> +want to write the image on.
> +
> +.. code-block:: console
> +
> +    dd if=openwrt-18.06.1-x86-64-combined-squashfs.img of=/dev/sdX
> +
> +Where sdX is name of the drive. (You can find it though ``fdisk -l``)
> +
> +Running DPDK
> +~~~~~~~~~~~~
> +
> +More detailed info about how to run a DPDK application please refer to
> +``Running DPDK Applications`` section of :ref:`the DPDK documentation <linux_gsg>`.
> +
> +.. note::
> +
> +    You need to install pre-built NUMA libraries (including soft link)
> +    to /usr/lib64 in OpenWrt.
> diff --git a/doc/guides/rel_notes/release_20_02.rst b/doc/guides/rel_notes/release_20_02.rst
> index 78dab7cfc..25df894a9 100644
> --- a/doc/guides/rel_notes/release_20_02.rst
> +++ b/doc/guides/rel_notes/release_20_02.rst
> @@ -229,6 +229,11 @@ New Features
>    Enhanced the compression performance tool by adding a cycle-count mode
>    which can be used to help measure and tune hardware and software PMDs.
>  
> +* **Added OpenWrt howto guide.**
> +
> +  Added document describes how to enable DPDK on OpenWrt in both virtual and
> +  physical machine.
> +
>  
>  Removed Items
>  -------------
> 



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