Re: [PATCH v11 0/1] Introduce AF_XDP PMD

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 4/4/2019 9:51 AM, Xiaolong Ye wrote:
> Overview
> ========
> 
> This patchset adds a new PMD driver for AF_XDP which is a proposed
> faster version of AF_PACKET interface in Linux, see below links [1] [2] for
> details of AF_XDP introduction:
> 
> AF_XDP roadmap
> ==============
> - AF_XDP is included in upstream kernel since 4.18, and AF_XDP support
>   in libbpf has been merged in v5.1-rc1.
> - Now i40e and ixgbe drivers have supported zero copy mode.
> 
> Change logs
> ===========
> v11:
> 
> - fix the meson build issue
> 
> v10:
> 
> - refine the Makefile, remove RTE_KERNELDIR related CFLAGS 
> - add a new internal file af_xdp_deps.h to handle the dependency for
>   asm/barrier.h
> - fix a typo observed by Stephen
> - rename xsk.h to bpf/xsk.h as xsk.h is assumed to be installed in
>   /usr/local/include/bpf
> - add libbpf build steps in af_xdp.rst
> 
> 
> v9:
> - adjust header files order according to Stephen's suggestion
> 
> v8:
> - address Ferruh's comments on V7
> - replace posix_memalign with rte_memzone_reserve_aligned to get better
>   performance
> - keep the first patch only as Oliver suggested as zero copy part
>   implementation is still in suspense, we may provide the related patch
>   later.
> 
> v7:
> - mention mtu limitation in af_xdp.rst
> - fix the vdev name in af_xdp.rst
> 
> V6:
> 
> - remove the newline in AF_XDP_LOG definition to avoid double new lines
>   issue.
> - rename MEMPOOL_F_PAGE_ALIGN to MEMPOOL_CHUNK_F_PAGE_ALIGN.
> 
> V5:
> 
> - disable AF_XDP pmd by default due to it requires kernel more recent
>   than minimum kernel version supported by DPDK
> - address other review comments of Maxime
> 
> V4:
> 
> - change vdev name to net_af_xdp
> - adopt dynamic log type for all logging
> - Fix other style issues raised by Stephen
> 
> V3:
> 
> - Fix all style issues pointed by Stephen, Mattias, David.
> - Drop the testpmd change as we'll adopt Jerin's suggestion to add a new
>   mempool driver to handle the application use of AF_XDP's zero copy feature.
> 
> V2:
> - Fix a NULL pointer reference crash issue
> - Fix txonly stop sending traffic in zc mode
> - Refactor rte_mbuf.c to avoid ABI breakage.
> - Fix multiple style issues pointed by Ferruh, David, Stephen, Luca.
> 
> changes vs RFC sent by Qi last Aug:
> 
> - Re-work base on AF_XDP's interface changes since the new libbpf has
>   provided higher-level APIs that hide many of the details of the AP_XDP
>   uapi. After the rework, it helps to reduce 300+ lines of code.
> 
> - multi-queues is not supported due to current libbpf doesn't support
>   multi-sockets on a single umem.
> 
> - No extra steps to load xdp program manually, since the current behavior of
>   libbpf would load a default xdp program when user calls xsk_socket__create.
>   userspace application only needs to handle the cleanup.
> 
> How to try
> ==========
> 
> 1. take the kernel >= v5.1-rc1, build kernel and replace your host
>    kernel with it.
>    
>    make sure you turn on XDP sockets when compiling
> 
>    Networking support -->
>         Networking options -->
>                 [ * ] XDP sockets
>    
> 2. build & install libbpf in tools/lib/bpf
> 
>    cd tools/lib/bpf
>    make install_lib
>    make install_headers
> 
> 3. ethtool -L enp59s0f0 combined 1
> 
> 4. extra step to build dpdk
> 
>    explicitly enable AF_XDP pmd by adding below line to
>    config/common_linux
> 
>    CONFIG_RTE_LIBRTE_PMD_AF_XDP=y
> 
> 5. start testpmd
> 
>    ./build/app/testpmd -c 0xc -n 4 --vdev net_af_xdp,iface=enp59s0f0,queue=0 -- -i --rxq=1 --txq=1
> 
>     in this case, default xdp program will be loaded and linked to queue 0 of enp59s0f0,
>     network traffics travel to queue 0 will be redirected to af_xdp socket.
> 
> Xiaolong Ye (1):
>   net/af_xdp: introduce AF XDP PMD driver

Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>