Re: [patch net-next v2 0/9] mlxsw: implement port mirroring offload

Fri, Jul 22, 2016 at 09:26:30PM CEST, f.fainelli@gmail.com wrote:

On 07/22/2016 12:20 PM, Jiri Pirko wrote:

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Fri, Jul 22, 2016 at 08:24:31PM CEST, f.fainelli@gmail.com wrote:

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On 07/21/2016 03:03 AM, Jiri Pirko wrote:

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From: Jiri Pirko <redacted>

This patchset introduces tc matchall classifier and its offload
to Spectrum hardware. In combination with mirred action, defined port mirroring
setup is offloaded by mlxsw/spectrum driver.

The commands used for creating mirror ports:

# ingress mirroring using matchall
tc qdisc  add dev eth25 handle ffff: ingress
tc filter add dev eth25 parent ffff:            \
        matchall skip_sw                        \
        action mirred egress mirror             \
        dev eth27

# egress mirroring using matchall
tc qdisc add dev eth25 handle 1: root prio
tc filter add dev eth25 parent 1:               \
        matchall skip_sw                        \
        action mirred egress mirror             \
        dev eth27

Is there any logic that guards against the following cases where the
target device is:

- outside of the switch hardware/cluster (which would imply going
through software)?

In that case only kernel (slow) path can be used. Not possible to
offload of course.

So then what happens if I target a device that is outside of the switch,
do we get an error like -EOPNOTSUPP, or this just silently succeeed, but
nothing happens?

As you can see, the check in mlxsw_sp_port_add_cls_matchall_mirror
returns -ENOTSUPP. That is handled in mall_change and is skip_sw is not
set, the rule is installed only in sw. This behaviour is aligned with
the rest of the ndo_setup_tc users, like cls_u32 and cls_flower.

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- has a downstream speed which is lower than the mirrored device?

The default behaviour is "strict" which means that if the mirrored
packet can't be send, the packet is dropped. That is aligned with the
behaviour of act_mirred.

What determines if the packet can be sent or not?

If there are free buffers for the packet to be send to mirroring device,
the original packet is sent and the mirrored as well.

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this might already be in place for 1), I just could not locate it, thanks!

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These patches contain:
 - Resource query implementation
 - Hardware port mirorring support for spectrum.
 - Definition of the matchall traffic classifier.
 - General support for hw-offloading for that classifier.
 - Specific spectrum implementaion for matchall offloading.

---
v1->v2:
 - couple of minor style fixes

Jiri Pirko (1):
  net/sched: introduce Match-all classifier

Nogah Frankel (2):
  mlxsw: pci: Add resources query implementation.
  mlxsw: pci: Add max span resources to resources query

Yotam Gigi (6):
  net/sched: Add match-all classifier hw offloading.
  mlxsw: reg: Add Shared Buffer Internal Buffer register
  mlxsw: reg: Add Monitoring Port Analyzer Table register
  mlxsw: reg: Add the Monitoring Port Analyzer register
  net/sched: act_mirred: Add helper inlines to access tcf_mirred info.
  mlxsw: spectrum: Add support in matchall mirror TC offloading

 drivers/net/ethernet/mellanox/mlxsw/cmd.h      |  32 ++
 drivers/net/ethernet/mellanox/mlxsw/core.c     |  10 +-
 drivers/net/ethernet/mellanox/mlxsw/core.h     |  11 +-
 drivers/net/ethernet/mellanox/mlxsw/pci.c      |  64 +++-
 drivers/net/ethernet/mellanox/mlxsw/reg.h      | 162 +++++++++
 drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 465 ++++++++++++++++++++++++-
 drivers/net/ethernet/mellanox/mlxsw/spectrum.h |  44 +++
 drivers/net/ethernet/mellanox/mlxsw/switchx2.c |   1 +
 include/linux/netdevice.h                      |   2 +
 include/net/pkt_cls.h                          |  11 +
 include/net/tc_act/tc_mirred.h                 |   9 +
 include/uapi/linux/pkt_cls.h                   |  12 +
 net/sched/Kconfig                              |  10 +
 net/sched/Makefile                             |   1 +
 net/sched/cls_matchall.c                       | 318 +++++++++++++++++
 15 files changed, 1148 insertions(+), 4 deletions(-)
 create mode 100644 net/sched/cls_matchall.c

-- 
Florian

-- 
Florian