[ovs-dev] [PATCHv15 2/2] netdev-afxdp: add new netdev type for AF_XDP.

[Ilya Maximets]

On 09.07.2019 22:35, William Tu wrote:
> The patch introduces experimental AF_XDP support for OVS netdev.
> AF_XDP, the Address Family of the eXpress Data Path, is a new Linux socket
> type built upon the eBPF and XDP technology.  It is aims to have comparable
> performance to DPDK but cooperate better with existing kernel's networking
> stack.  An AF_XDP socket receives and sends packets from an eBPF/XDP program
> attached to the netdev, by-passing a couple of Linux kernel's subsystems
> As a result, AF_XDP socket shows much better performance than AF_PACKET
> For more details about AF_XDP, please see linux kernel's
> Documentation/networking/af_xdp.rst. Note that by default, this feature is
> not compiled in.
> 
> Signed-off-by: William Tu <u9012063 at gmail.com>
> ---
> v14:
>  * Mainly address issue reported by Ilya
>    https://protect2.fireeye.com/url?k=0b6c291c248670fb.0b6da253-6021601b254970fd&u=https://patchwork.ozlabs.org/patch/1118972/
>    when doing 'make check-afxdp'
>  * Fix xdp frame headroom issue
>  * Fix vlan test cases by disabling txvlan offload
>  * Skip cvlan
>  * Document TCP limitation (currently all tcp tests fail due to
>    kernel veth driver)
>  * Fix tunnel test cases due to --disable-system (another patch)
>  * Switch to use pthread_spin_lock, suggested by Ben
>  * Add coverage counter for debugging
>  * Fix buffer starvation issue at batch_send reported by Eelco
>    when using tap device with type=afxdp
> 
> v15:
>  * address review feedback from Ilay
>    https://protect2.fireeye.com/url?k=ceb755d3074c79a5.ceb6de9c-b1b2f6a490a479b8&u=https://patchwork.ozlabs.org/patch/1125476/
>  * skip TCP related test cases
>  * reclaim all CONS_NUM_DESC at complete tx
>  * add retries to kick_tx
>  * increase memory pool size
>  * remove redundant xdp flag and bind flag
>  * remove unused rx_dropped var
>  * make tx_dropped counter atomic
>  * refactor dp_packet_init_afxdp using dp_packet_init__
>  * rebase to ovs master, test with latest bpf-next kernel commit b14a260e33ddb4
>    Ilya's kernel patches are required
>    commit 455302d1c9ae ("xdp: fix hang while unregistering device bound to xdp socket")
>    commit 162c820ed896 ("xdp: hold device for umem regardless of zero-copy mode")
>  Possible issues:
>  * still lots of afxdp_cq_skip  (ovs-appctl coverage/show)
>     afxdp_cq_skip  44325273.6/sec 34362312.683/sec   572705.2114/sec   total: 2106010377
>  * TODO:
>    'make check-afxdp' still not all pass
>    IP fragmentation expiry test not fix yet, need to implement
>    deferral memory free, s.t like dpdk_mp_sweep.  Currently hit
>    some missing umem descs when reclaiming.
>    NSH test case still failed (not due to afxdp)
> ---
>  Documentation/automake.mk             |   1 +
>  Documentation/index.rst               |   1 +
>  Documentation/intro/install/afxdp.rst | 430 ++++++++++++++++
>  Documentation/intro/install/index.rst |   1 +
>  acinclude.m4                          |  35 ++
>  configure.ac                          |   1 +
>  lib/automake.mk                       |  13 +
>  lib/dp-packet.c                       |  23 +
>  lib/dp-packet.h                       |  18 +-
>  lib/dpif-netdev-perf.h                |  26 +
>  lib/netdev-afxdp.c                    | 933 ++++++++++++++++++++++++++++++++++
>  lib/netdev-afxdp.h                    |  74 +++
>  lib/netdev-linux-private.h            | 138 +++++
>  lib/netdev-linux.c                    | 121 ++---
>  lib/netdev-provider.h                 |   3 +
>  lib/netdev.c                          |  11 +
>  lib/util.c                            |  92 +++-
>  lib/util.h                            |   5 +
>  lib/xdpsock.c                         | 170 +++++++
>  lib/xdpsock.h                         | 103 ++++
>  tests/automake.mk                     |  16 +
>  tests/system-afxdp-macros.at          |  39 ++
>  tests/system-afxdp-testsuite.at       |  26 +
>  tests/system-traffic.at               |   2 +
>  vswitchd/vswitch.xml                  |  15 +
>  25 files changed, 2189 insertions(+), 108 deletions(-)
>  create mode 100644 Documentation/intro/install/afxdp.rst
>  create mode 100644 lib/netdev-afxdp.c
>  create mode 100644 lib/netdev-afxdp.h
>  create mode 100644 lib/netdev-linux-private.h
>  create mode 100644 lib/xdpsock.c
>  create mode 100644 lib/xdpsock.h
>  create mode 100644 tests/system-afxdp-macros.at
>  create mode 100644 tests/system-afxdp-testsuite.at

Please, add 'system-afxdp-testsuite' executable and friends to tests/.gitignore.

Best regards, Ilya Maximets.