[RFC PATCH net-next 0/3] selftests: Add AF_XDP functionality test

[YiFei Zhu <zhuyifei@google.com>]

We have observed that hardware NIC drivers may have faulty AF_XDP
implementations, and there seem to be a lack of a test of various modes
in which AF_XDP could run. This series adds a test to verify that NIC
drivers implements many AF_XDP features by performing a send / receive
of a single UDP packet.

I put the C code of the test under selftests/bpf because I'm not really
sure how I'd build the BPF-related code without the selftests/bpf
build infrastructure.

Tested on Google Cloud, with GVE:

  $ sudo NETIF=ens4 REMOTE_TYPE=ssh \
    REMOTE_ARGS="root@10.138.15.235" \
    LOCAL_V4="10.138.15.234" \
    REMOTE_V4="10.138.15.235" \
    LOCAL_NEXTHOP_MAC="42:01:0a:8a:00:01" \
    REMOTE_NEXTHOP_MAC="42:01:0a:8a:00:01" \
    python3 xsk_hw.py

  KTAP version 1
  1..22
  ok 1 xsk_hw.ipv4_basic
  ok 2 xsk_hw.ipv4_tx_skb_copy
  ok 3 xsk_hw.ipv4_tx_skb_copy_force_attach
  ok 4 xsk_hw.ipv4_rx_skb_copy
  ok 5 xsk_hw.ipv4_tx_drv_copy
  ok 6 xsk_hw.ipv4_tx_drv_copy_force_attach
  ok 7 xsk_hw.ipv4_rx_drv_copy
  [...]
  # Exception| STDERR: b'/tmp/zzfhcqkg/pbgodkgjxsk_hw: recv_pfpacket: Timeout\n'
  not ok 8 xsk_hw.ipv4_tx_drv_zerocopy
  ok 9 xsk_hw.ipv4_tx_drv_zerocopy_force_attach
  ok 10 xsk_hw.ipv4_rx_drv_zerocopy
  [...]
  # Exception| STDERR: b'/tmp/zzfhcqkg/pbgodkgjxsk_hw: connect sync client: max_retries\n'
  [...]
  # Exception| STDERR: b'/linux/tools/testing/selftests/bpf/xsk_hw: open_xsk: Device or resource busy\n'
  not ok 11 xsk_hw.ipv4_rx_drv_zerocopy_fill_after_bind
  ok 12 xsk_hw.ipv6_basic # SKIP Test requires IPv6 connectivity
  [...]
  ok 22 xsk_hw.ipv6_rx_drv_zerocopy_fill_after_bind # SKIP Test requires IPv6 connectivity
  # Totals: pass:9 fail:2 xfail:0 xpass:0 skip:11 error:0

YiFei Zhu (3):
  selftests/bpf: Move rxq_num helper from xdp_hw_metadata to
    network_helpers
  selftests/bpf: Add xsk_hw AF_XDP functionality test
  selftests: drv-net: Add xsk_hw AF_XDP functionality test

 tools/testing/selftests/bpf/.gitignore        |   1 +
 tools/testing/selftests/bpf/Makefile          |   7 +-
 tools/testing/selftests/bpf/network_helpers.c |  27 +
 tools/testing/selftests/bpf/network_helpers.h |  16 +
 tools/testing/selftests/bpf/progs/xsk_hw.c    |  72 ++
 tools/testing/selftests/bpf/xdp_hw_metadata.c |  27 +-
 tools/testing/selftests/bpf/xsk_hw.c          | 844 ++++++++++++++++++
 .../testing/selftests/drivers/net/hw/Makefile |   1 +
 .../selftests/drivers/net/hw/xsk_hw.py        | 133 +++
 9 files changed, 1102 insertions(+), 26 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/xsk_hw.c
 create mode 100644 tools/testing/selftests/bpf/xsk_hw.c
 create mode 100755 tools/testing/selftests/drivers/net/hw/xsk_hw.py

-- 
2.45.2.505.gda0bf45e8d-goog