[dpdk-dev] [PATCH v1 1/6] net/af_xdp: introduce AF_XDP PMD driver

[Luca Boccassi]

On Fri, 2019-03-01 at 16:09 +0800, Xiaolong Ye 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 at intel.com>
> ---
>  MAINTAINERS                                   |   6 +
>  config/common_base                            |   5 +
>  doc/guides/nics/af_xdp.rst                    |  43 +
>  doc/guides/rel_notes/release_18_11.rst        |   7 +
>  drivers/net/Makefile                          |   1 +
>  drivers/net/af_xdp/Makefile                   |  31 +
>  drivers/net/af_xdp/meson.build                |   7 +
>  drivers/net/af_xdp/rte_eth_af_xdp.c           | 903
> ++++++++++++++++++
>  drivers/net/af_xdp/rte_pmd_af_xdp_version.map |   4 +
>  mk/rte.app.mk                                 |   1 +
>  10 files changed, 1008 insertions(+)
>  create mode 100644 doc/guides/nics/af_xdp.rst
>  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
> 
<..>

> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -9,6 +9,7 @@ ifeq ($(CONFIG_RTE_LIBRTE_THUNDERX_NICVF_PMD),d)
>  endif
>  
>  DIRS-$(CONFIG_RTE_LIBRTE_PMD_AF_PACKET) += af_packet
> +DIRS-$(CONFIG_RTE_LIBRTE_PMD_AF_XDP) += af_xdp
>  DIRS-$(CONFIG_RTE_LIBRTE_ARK_PMD) += ark
>  DIRS-$(CONFIG_RTE_LIBRTE_ATLANTIC_PMD) += atlantic
>  DIRS-$(CONFIG_RTE_LIBRTE_AVF_PMD) += avf

You need a similar change in drivers/net/meson.build

> diff --git a/drivers/net/af_xdp/Makefile
> b/drivers/net/af_xdp/Makefile
> new file mode 100644
> index 000000000..e3755fff2
> --- /dev/null
> +++ b/drivers/net/af_xdp/Makefile
> @@ -0,0 +1,31 @@
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright(c) 2018 Intel Corporation
> +
> +include $(RTE_SDK)/mk/rte.vars.mk
> +
> +#
> +# library name
> +#
> +LIB = librte_pmd_af_xdp.a
> +
> +EXPORT_MAP := rte_pmd_af_xdp_version.map
> +
> +LIBABIVER := 1
> +
> +
> +CFLAGS += -O3
> +# below line should be removed
> +CFLAGS += -I/root/yexl/shared_mks0/linux/tools/include
> +CFLAGS += -I/root/yexl/shared_mks0/linux/tools/lib/bpf

Leftovers?

> +CFLAGS += $(WERROR_FLAGS)
> +LDLIBS += -lrte_eal -lrte_mbuf -lrte_mempool -lrte_ring
> +LDLIBS += -lrte_ethdev -lrte_net -lrte_kvargs
> +LDLIBS += -lrte_bus_vdev
> +
> +#
> +# all source are stored in SRCS-y
> +#
> +SRCS-$(CONFIG_RTE_LIBRTE_PMD_AF_XDP) += rte_eth_af_xdp.c
> +
> +include $(RTE_SDK)/mk/rte.lib.mk
> diff --git a/drivers/net/af_xdp/meson.build
> b/drivers/net/af_xdp/meson.build
> new file mode 100644
> index 000000000..4b6652685
> --- /dev/null
> +++ b/drivers/net/af_xdp/meson.build
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: BSD-3-Clause
> +# Copyright(c) 2018 Intel Corporation
> +
> +if host_machine.system() != 'linux'
> +	build = false
> +endif
> +sources = files('rte_eth_af_xdp.c')

You need to add a dependency() on libbpf, and given upstream doesn't
ship a pkg-config file yet a fallback to find_library, so that the pmd
can be linked against it.
Check other PMDs to see how dependencies are handled, like
drivers/net/pcap/meson.build

<..>

> diff --git a/drivers/net/af_xdp/rte_pmd_af_xdp_version.map
> b/drivers/net/af_xdp/rte_pmd_af_xdp_version.map
> new file mode 100644
> index 000000000..ef3539840
> --- /dev/null
> +++ b/drivers/net/af_xdp/rte_pmd_af_xdp_version.map
> @@ -0,0 +1,4 @@
> +DPDK_2.0 {

2.0 is a bit old :-)

> +
> +	local: *;
> +};
> diff --git a/mk/rte.app.mk b/mk/rte.app.mk
> index d0ab942d5..db3271c7b 100644
> --- a/mk/rte.app.mk
> +++ b/mk/rte.app.mk
> @@ -143,6 +143,7 @@ _LDLIBS-$(CONFIG_RTE_LIBRTE_DPAA2_MEMPOOL)  +=
> -lrte_mempool_dpaa2
>  endif
>  
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_PMD_AF_PACKET)  += -lrte_pmd_af_packet
> +_LDLIBS-$(CONFIG_RTE_LIBRTE_PMD_AF_XDP)     += -lrte_pmd_af_xdp
> -lelf -lbpf

Are symbols from libelf being used by the PMD?

>  _LDLIBS-$(CONFIG_RTE_LIBRTE_ARK_PMD)        += -lrte_pmd_ark
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_ATLANTIC_PMD)   += -lrte_pmd_atlantic
>  _LDLIBS-$(CONFIG_RTE_LIBRTE_AVF_PMD)        += -lrte_pmd_avf

-- 
Kind regards,
Luca Boccassi