[net-next,0/3] netdevsim: Support for L3 HW stats

Message

Petr Machata March 10, 2022, 4:12 p.m. UTC

"L3 stats" is a suite of interface statistics aimed at reflecting traffic
taking place in a HW device, on an object corresponding to some software
netdevice. Support for this stats suite has been added recently, in commit
ca0a53dcec94 ("Merge branch 'net-hw-counters-for-soft-devices'").

In this patch set:

- Patch #1 adds support for L3 stats to netdevsim.

  Real devices can have various conditions for when an L3 counter is
  available. To simulate this, netdevsim maintains a list of devices
  suitable for HW stats collection. Only when l3_stats is enabled on both a
  netdevice itself, and in netdevsim, will netdevsim contribute values to
  L3 stats.

  This enablement and disablement is done via debugfs:

    # echo $ifindex > /sys/kernel/debug/netdevsim/$DEV/hwstats/l3/enable_ifindex
    # echo $ifindex > /sys/kernel/debug/netdevsim/$DEV/hwstats/l3/disable_ifindex

  Besides this, there is a third toggle to mark a device for future failure:

    # echo $ifindex > /sys/kernel/debug/netdevsim/$DEV/hwstats/l3/fail_next_enable

- This allows HW-independent testing of stats reporting and in-kernel APIs,
  as well as a test for enablement rollback, which is difficult to do
  otherwise. This netdevsim-specific selftest is added in patch #2.

- Patch #3 adds another driver-specific selftest, namely a test aimed at
  checking mlxsw-induced stats monitoring events.

Petr Machata (3):
  netdevsim: Introduce support for L3 offload xstats
  selftests: netdevsim: hw_stats_l3: Add a new test
  selftests: mlxsw: hw_stats_l3: Add a new test

 drivers/net/netdevsim/Makefile                |   2 +-
 drivers/net/netdevsim/dev.c                   |  17 +-
 drivers/net/netdevsim/hwstats.c               | 497 ++++++++++++++++++
 drivers/net/netdevsim/netdevsim.h             |  23 +
 .../drivers/net/mlxsw/hw_stats_l3.sh          |  31 ++
 .../drivers/net/netdevsim/hw_stats_l3.sh      | 421 +++++++++++++++
 tools/testing/selftests/net/forwarding/lib.sh |  60 +++
 7 files changed, 1048 insertions(+), 3 deletions(-)
 create mode 100644 drivers/net/netdevsim/hwstats.c
 create mode 100755 tools/testing/selftests/drivers/net/mlxsw/hw_stats_l3.sh
 create mode 100755 tools/testing/selftests/drivers/net/netdevsim/hw_stats_l3.sh