Re: [PATCH net,v3] net: flow_offload: skip hw stats check for FLOW_ACTION_HW_STATS_DONT_CARE

[Jiri Pirko <jiri@resnulli.us>]

Wed, May 06, 2020 at 01:55:39PM CEST, pablo@netfilter.org wrote:
>This patch adds FLOW_ACTION_HW_STATS_DONT_CARE which tells the driver
>that the frontend does not need counters, this hw stats type request
>never fails. The FLOW_ACTION_HW_STATS_DISABLED type explicitly requests
>the driver to disable the stats, however, if the driver cannot disable
>counters, it bails out.
>
>TCA_ACT_HW_STATS_* maintains the 1:1 mapping with FLOW_ACTION_HW_STATS_*
>except by disabled which is mapped to FLOW_ACTION_HW_STATS_DISABLED
>(this is 0 in tc). Add tc_act_hw_stats() to perform the mapping between
>TCA_ACT_HW_STATS_* and FLOW_ACTION_HW_STATS_*.
>
>Fixes: 319a1d19471e ("flow_offload: check for basic action hw stats type")
>Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
>---
>v3: update mlxsw to handle _DONT_CARE.
>
> .../net/ethernet/mellanox/mlxsw/spectrum_flower.c  |  2 +-
> include/net/flow_offload.h                         |  9 ++++++++-
> net/sched/cls_api.c                                | 14 ++++++++++++--
> 3 files changed, 21 insertions(+), 4 deletions(-)
>
>diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
>index 51117a5a6bbf..81d0b3481479 100644
>--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
>+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_flower.c
>@@ -36,7 +36,7 @@ static int mlxsw_sp_flower_parse_actions(struct mlxsw_sp *mlxsw_sp,
> 		err = mlxsw_sp_acl_rulei_act_count(mlxsw_sp, rulei, extack);
> 		if (err)
> 			return err;
>-	} else if (act->hw_stats != FLOW_ACTION_HW_STATS_DISABLED) {
>+	} else if (act->hw_stats == FLOW_ACTION_HW_STATS_DELAYED) {

I think that better is:
	} else if (act->hw_stats != FLOW_ACTION_HW_STATS_DISABLED &&
		   act->hw_stats != FLOW_ACTION_HW_STATS_DONT_CARE) {

> 		NL_SET_ERR_MSG_MOD(extack, "Unsupported action HW stats type");
> 		return -EOPNOTSUPP;
> 	}