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

[Ye Xiaolong]

Hi, Luca

Thanks for your review.

On 03/01, Luca Boccassi wrote:
>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

will do.

>
>> 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?
>

Yes, will remove in next version.

>> +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
>

will check the example to see how to handle it correctly.

><..>
>
>> 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 :-)

will change it.

>
>> +
>> +	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?

Hmm, it is a leftover of RFC, libelf is no longer needed in this version, will
remove it in next version.

Thanks,
Xiaolong
>
>>  _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