Re: [PATCH net-next v4 5/8] net: sched: add extack support for offload via tc_cls_common_offload

[Jiri Pirko <jiri@resnulli.us>]

Sat, Jan 20, 2018 at 02:44:47AM CET, jakub.kicinski@netronome.com wrote:
>From: Quentin Monnet <quentin.monnet@netronome.com>
>
>Add extack support for hardware offload of classifiers. In order
>to achieve this, a pointer to a struct netlink_ext_ack is added to the
>struct tc_cls_common_offload that is passed to the callback for setting
>up the classifier. Function tc_cls_common_offload_init() is updated to
>support initialization of this new attribute.
>
>Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
>Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
>---
> include/net/pkt_cls.h    | 5 ++++-
> net/sched/cls_bpf.c      | 4 ++--
> net/sched/cls_flower.c   | 6 +++---
> net/sched/cls_matchall.c | 4 ++--
> net/sched/cls_u32.c      | 8 ++++----
> 5 files changed, 15 insertions(+), 12 deletions(-)
>
>diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
>index 2e4b8e436d25..f497f622580b 100644
>--- a/include/net/pkt_cls.h
>+++ b/include/net/pkt_cls.h
>@@ -602,15 +602,18 @@ struct tc_cls_common_offload {
> 	u32 chain_index;
> 	__be16 protocol;
> 	u32 prio;
>+	struct netlink_ext_ack *extack;
> };
> 
> static inline void
> tc_cls_common_offload_init(struct tc_cls_common_offload *cls_common,
>-			   const struct tcf_proto *tp)
>+			   const struct tcf_proto *tp,
>+			   struct netlink_ext_ack *extack)
> {
> 	cls_common->chain_index = tp->chain->index;
> 	cls_common->protocol = tp->protocol;
> 	cls_common->prio = tp->prio;
>+	cls_common->extack = extack;
> }

[...]


>diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
>index f675a92e1b66..727c10378f37 100644
>--- a/net/sched/cls_flower.c
>+++ b/net/sched/cls_flower.c
>@@ -223,7 +223,7 @@ static void fl_hw_destroy_filter(struct tcf_proto *tp, struct cls_fl_filter *f)
> 	struct tc_cls_flower_offload cls_flower = {};
> 	struct tcf_block *block = tp->chain->block;
> 
>-	tc_cls_common_offload_init(&cls_flower.common, tp);
>+	tc_cls_common_offload_init(&cls_flower.common, tp, NULL);

While you are at it, you should propagate extack whenever possible. For
this, you can easily pass extack to fl_hw_destroy_filter.
Same for other classifiers.


> 	cls_flower.command = TC_CLSFLOWER_DESTROY;
> 	cls_flower.cookie = (unsigned long) f;
> 
>@@ -243,7 +243,7 @@ static int fl_hw_replace_filter(struct tcf_proto *tp,
> 	bool skip_sw = tc_skip_sw(f->flags);
> 	int err;
> 
>-	tc_cls_common_offload_init(&cls_flower.common, tp);
>+	tc_cls_common_offload_init(&cls_flower.common, tp, extack);
> 	cls_flower.command = TC_CLSFLOWER_REPLACE;
> 	cls_flower.cookie = (unsigned long) f;
> 	cls_flower.dissector = dissector;
>@@ -272,7 +272,7 @@ static void fl_hw_update_stats(struct tcf_proto *tp, struct cls_fl_filter *f)
> 	struct tc_cls_flower_offload cls_flower = {};
> 	struct tcf_block *block = tp->chain->block;
> 
>-	tc_cls_common_offload_init(&cls_flower.common, tp);
>+	tc_cls_common_offload_init(&cls_flower.common, tp, NULL);

For this, it would be probably a bit trickier to get extack, but also
possible.
My motivation is to make the extack always available for users of
tc_cls_common_offload


> 	cls_flower.command = TC_CLSFLOWER_STATS;
> 	cls_flower.cookie = (unsigned long) f;
> 	cls_flower.exts = &f->exts;

[...]