[PATCH net-next v4 0/6] net/sched: cls_api: Support hardware miss to tc action

[PATCH net-next v4 0/6] net/sched: cls_api: Support hardware miss to tc action

[Paul Blakey]

Hi,

This series adds support for hardware miss to instruct tc to continue execution
in a specific tc action instance on a filter's action list. The mlx5 driver patch
(besides the refactors) shows its usage instead of using just chain restore.

Currently a filter's action list must be executed all together or
not at all as driver are only able to tell tc to continue executing from a
specific tc chain, and not a specific filter/action.

This is troublesome with regards to action CT, where new connections should
be sent to software (via tc chain restore), and established connections can
be handled in hardware.

Checking for new connections is done when executing the ct action in hardware
(by checking the packet's tuple against known established tuples).
But if there is a packet modification (pedit) action before action CT and the
checked tuple is a new connection, hardware will need to revert the previous
packet modifications before sending it back to software so it can
re-match the same tc filter in software and re-execute its CT action.

The following is an example configuration on mlx5 driver that isn't
supported before this patchet:

 #Setup corrosponding mlx5 VFs in namespaces
 $ ip netns add ns0
 $ ip netns add ns1
 $ ip link set dev enp8s0f0v0 netns ns0
 $ ip netns exec ns0 ifconfig enp8s0f0v0 1.1.1.1/24 up
 $ ip link set dev enp8s0f0v1 netns ns1
 $ ip netns exec ns1 ifconfig enp8s0f0v1 1.1.1.2/24 up

 #Setup tc arp and ct rules on mxl5 VF representors
 $ tc qdisc add dev enp8s0f0_0 ingress
 $ tc qdisc add dev enp8s0f0_1 ingress
 $ ifconfig enp8s0f0_0 up
 $ ifconfig enp8s0f0_1 up

 #Original side
 $ tc filter add dev enp8s0f0_0 ingress chain 0 proto ip flower \
    ct_state -trk ip_proto tcp dst_port 8888 \
      action pedit ex munge tcp dport set 5001 pipe \
      action csum ip tcp pipe \
      action ct pipe \
      action goto chain 1
 $ tc filter add dev enp8s0f0_0 ingress chain 1 proto ip flower \
    ct_state +trk+est \
      action mirred egress redirect dev enp8s0f0_1
 $ tc filter add dev enp8s0f0_0 ingress chain 1 proto ip flower \
    ct_state +trk+new \
      action ct commit pipe \
      action mirred egress redirect dev enp8s0f0_1
 $ tc filter add dev enp8s0f0_0 ingress chain 0 proto arp flower \
      action mirred egress redirect dev enp8s0f0_1

 #Reply side
 $ tc filter add dev enp8s0f0_1 ingress chain 0 proto arp flower \
      action mirred egress redirect dev enp8s0f0_0
 $ tc filter add dev enp8s0f0_1 ingress chain 0 proto ip flower \
    ct_state -trk ip_proto tcp \ 
      action ct pipe \
      action pedit ex munge tcp sport set 8888 pipe \
      action csum ip tcp pipe \
      action mirred egress redirect dev enp8s0f0_0

 #Run traffic
 $ ip netns exec ns1 iperf -s -p 5001&
 $ sleep 2 #wait for iperf to fully open
 $ ip netns exec ns0 iperf -c 1.1.1.2 -p 8888

A new connection executing the first filter in hardware will first rewrite
the dst port to the new port, and then the ct action is executed,
because this is a new connection, hardware will need to be send this back
to software, on chain 0, to execute the first filter again in software.
The dst port needs to be reverted otherwise it won't re-match the old
dst port in the first filter. Because of that, currently mlx5 driver will
reject offloading the above action ct rule.

This series adds supports partial offload of a filter's action list,
and letting tc software continue processing in the specific action instance
where hardware left off (in the above case after the "action pedit ex munge tcp
dport.. of the first rule") allowing support for scenarios such as the above.

Changelog:
	v1->v2:
	Fixed compilation without CONFIG_NET_CLS
	Cover letter re-write

	v2->v3:
	Unlock spin_lock on error in cls flower filter handle refactor
	Cover letter

	v3->v4:
	Silence warning by clang

Paul Blakey (6):
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: flower: Support hardware miss to tc action
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: TC, Set CT miss to the specific ct action instance

 .../ethernet/mellanox/mlx5/core/en/rep/tc.c   | 225 ++------------
 .../mellanox/mlx5/core/en/tc/sample.c         |   2 +-
 .../ethernet/mellanox/mlx5/core/en/tc_ct.c    |  32 +-
 .../ethernet/mellanox/mlx5/core/en/tc_ct.h    |   2 +
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |   4 +-
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   | 276 ++++++++++++++++--
 .../net/ethernet/mellanox/mlx5/core/en_tc.h   |  21 +-
 .../net/ethernet/mellanox/mlx5/core/eswitch.h |   2 +
 .../mellanox/mlx5/core/lib/fs_chains.c        |  14 +-
 include/linux/skbuff.h                        |   6 +-
 include/net/flow_offload.h                    |   1 +
 include/net/pkt_cls.h                         |  22 +-
 include/net/sch_generic.h                     |   2 +
 net/openvswitch/flow.c                        |   2 +-
 net/sched/act_api.c                           |   2 +-
 net/sched/cls_api.c                           | 210 ++++++++++++-
 net/sched/cls_flower.c                        |  73 +++--
 17 files changed, 582 insertions(+), 314 deletions(-)

-- 
2.30.1

[PATCH net-next v4 1/6] net/sched: cls_api: Support hardware miss to tc action

[Paul Blakey]

For drivers to support partial offload of a filter's action list,
add support for action miss to specify an action instance to
continue from in sw.

CT action in particular can't be fully offloaded, as new connections
need to be handled in software. This imposes other limitations on
the actions that can be offloaded together with the CT action, such
as packet modifications.

Assign each action on a filter's action list a unique miss_cookie
which drivers can then use to fill action_miss part of the tc skb
extension. On getting back this miss_cookie, find the action
instance with relevant cookie and continue classifying from there.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 include/linux/skbuff.h     |   6 +-
 include/net/flow_offload.h |   1 +
 include/net/pkt_cls.h      |  22 ++--
 include/net/sch_generic.h  |   2 +
 net/openvswitch/flow.c     |   2 +-
 net/sched/act_api.c        |   2 +-
 net/sched/cls_api.c        | 210 +++++++++++++++++++++++++++++++++++--
 7 files changed, 218 insertions(+), 27 deletions(-)

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 4c8492401a101..348673dcb6bb9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -316,12 +316,16 @@ struct nf_bridge_info {
  * and read by ovs to recirc_id.
  */
 struct tc_skb_ext {
-	__u32 chain;
+	union {
+		u64 act_miss_cookie;
+		__u32 chain;
+	};
 	__u16 mru;
 	__u16 zone;
 	u8 post_ct:1;
 	u8 post_ct_snat:1;
 	u8 post_ct_dnat:1;
+	u8 act_miss:1; /* Set if act_miss_cookie is used */
 };
 #endif
 
diff --git a/include/net/flow_offload.h b/include/net/flow_offload.h
index 0400a0ac8a295..88db7346eb7a0 100644
--- a/include/net/flow_offload.h
+++ b/include/net/flow_offload.h
@@ -228,6 +228,7 @@ void flow_action_cookie_destroy(struct flow_action_cookie *cookie);
 struct flow_action_entry {
 	enum flow_action_id		id;
 	u32				hw_index;
+	u64				miss_cookie;
 	enum flow_action_hw_stats	hw_stats;
 	action_destr			destructor;
 	void				*destructor_priv;
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 4cabb32a2ad94..9ef85cf9b5328 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -59,6 +59,8 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
 void tcf_block_put(struct tcf_block *block);
 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
 		       struct tcf_block_ext_info *ei);
+int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action, int police,
+		     struct tcf_proto *tp, u32 handle, bool used_action_miss);
 
 static inline bool tcf_block_shared(struct tcf_block *block)
 {
@@ -229,6 +231,7 @@ struct tcf_exts {
 	struct tc_action **actions;
 	struct net	*net;
 	netns_tracker	ns_tracker;
+	struct tcf_exts_miss_cookie_node *miss_cookie_node;
 #endif
 	/* Map to export classifier specific extension TLV types to the
 	 * generic extensions API. Unsupported extensions must be set to 0.
@@ -240,21 +243,11 @@ struct tcf_exts {
 static inline int tcf_exts_init(struct tcf_exts *exts, struct net *net,
 				int action, int police)
 {
-#ifdef CONFIG_NET_CLS_ACT
-	exts->type = 0;
-	exts->nr_actions = 0;
-	/* Note: we do not own yet a reference on net.
-	 * This reference might be taken later from tcf_exts_get_net().
-	 */
-	exts->net = net;
-	exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
-				GFP_KERNEL);
-	if (!exts->actions)
-		return -ENOMEM;
+#ifdef CONFIG_NET_CLS
+	return tcf_exts_init_ex(exts, net, action, police, NULL, 0, false);
+#else
+	return -EOPNOTSUPP;
 #endif
-	exts->action = action;
-	exts->police = police;
-	return 0;
 }
 
 /* Return false if the netns is being destroyed in cleanup_net(). Callers
@@ -577,6 +570,7 @@ int tc_setup_offload_action(struct flow_action *flow_action,
 void tc_cleanup_offload_action(struct flow_action *flow_action);
 int tc_setup_action(struct flow_action *flow_action,
 		    struct tc_action *actions[],
+		    u32 miss_cookie_base,
 		    struct netlink_ext_ack *extack);
 
 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index af4aa66aaa4eb..fab5ba3e61b7c 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -369,6 +369,8 @@ struct tcf_proto_ops {
 						struct nlattr **tca,
 						struct netlink_ext_ack *extack);
 	void			(*tmplt_destroy)(void *tmplt_priv);
+	struct tcf_exts *	(*get_exts)(const struct tcf_proto *tp,
+					    u32 handle);
 
 	/* rtnetlink specific */
 	int			(*dump)(struct net*, struct tcf_proto*, void *,
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index e20d1a9734175..b1a5eed8d1a9d 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -1038,7 +1038,7 @@ int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 	if (tc_skb_ext_tc_enabled()) {
 		tc_ext = skb_ext_find(skb, TC_SKB_EXT);
-		key->recirc_id = tc_ext ? tc_ext->chain : 0;
+		key->recirc_id = tc_ext && !tc_ext->act_miss ? tc_ext->chain : 0;
 		OVS_CB(skb)->mru = tc_ext ? tc_ext->mru : 0;
 		post_ct = tc_ext ? tc_ext->post_ct : false;
 		post_ct_snat = post_ct ? tc_ext->post_ct_snat : false;
diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index cd09ef49df22d..16fd3d30eb121 100644
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -272,7 +272,7 @@ static int tcf_action_offload_add_ex(struct tc_action *action,
 	if (err)
 		goto fl_err;
 
-	err = tc_setup_action(&fl_action->action, actions, extack);
+	err = tc_setup_action(&fl_action->action, actions, 0, extack);
 	if (err) {
 		NL_SET_ERR_MSG_MOD(extack,
 				   "Failed to setup tc actions for offload");
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 5b4a95e8a1ee0..46524ae353c5a 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -22,6 +22,7 @@
 #include <linux/idr.h>
 #include <linux/jhash.h>
 #include <linux/rculist.h>
+#include <linux/rhashtable.h>
 #include <net/net_namespace.h>
 #include <net/sock.h>
 #include <net/netlink.h>
@@ -50,6 +51,98 @@ static LIST_HEAD(tcf_proto_base);
 /* Protects list of registered TC modules. It is pure SMP lock. */
 static DEFINE_RWLOCK(cls_mod_lock);
 
+static struct xarray tcf_exts_miss_cookies_xa;
+struct tcf_exts_miss_cookie_node {
+	const struct tcf_chain *chain;
+	const struct tcf_proto *tp;
+	const struct tcf_exts *exts;
+	u32 chain_index;
+	u32 tp_prio;
+	u32 handle;
+	u32 miss_cookie_base;
+	struct rcu_head rcu;
+};
+
+/* Each tc action entry cookie will be comprised of 32bit miss_cookie_base +
+ * action index in the exts tc actions array.
+ */
+union tcf_exts_miss_cookie {
+	struct {
+		u32 miss_cookie_base;
+		u32 act_index;
+	};
+	u64 miss_cookie;
+};
+
+#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+static int
+tcf_exts_miss_cookie_base_alloc(struct tcf_exts *exts, struct tcf_proto *tp,
+				u32 handle)
+{
+	struct tcf_exts_miss_cookie_node *n;
+	static u32 next;
+	int err;
+
+	if (WARN_ON(!handle || !tp->ops->get_exts))
+		return -EINVAL;
+
+	n = kzalloc(sizeof(*n), GFP_KERNEL);
+	if (!n)
+		return -ENOMEM;
+
+	n->chain_index = tp->chain->index;
+	n->chain = tp->chain;
+	n->tp_prio = tp->prio;
+	n->tp = tp;
+	n->exts = exts;
+	n->handle = handle;
+
+	err = xa_alloc_cyclic(&tcf_exts_miss_cookies_xa, &n->miss_cookie_base,
+			      n, xa_limit_32b, &next, GFP_KERNEL);
+	if (err)
+		goto err_xa_alloc;
+
+	exts->miss_cookie_node = n;
+	return 0;
+
+err_xa_alloc:
+	kfree(n);
+	return err;
+}
+
+static void tcf_exts_miss_cookie_base_destroy(struct tcf_exts *exts)
+{
+	struct tcf_exts_miss_cookie_node *n;
+
+	if (!exts->miss_cookie_node)
+		return;
+
+	n = exts->miss_cookie_node;
+	xa_erase(&tcf_exts_miss_cookies_xa, n->miss_cookie_base);
+	kfree_rcu(n, rcu);
+}
+
+static struct tcf_exts_miss_cookie_node *
+tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
+{
+	union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
+
+	*act_index = mc.act_index;
+	return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
+}
+#endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
+
+static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
+{
+	union tcf_exts_miss_cookie mc = { .act_index = act_index, };
+
+	if (!miss_cookie_base)
+		return 0;
+
+	mc.miss_cookie_base = miss_cookie_base;
+	return mc.miss_cookie;
+}
+
 #ifdef CONFIG_NET_CLS_ACT
 DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
 EXPORT_SYMBOL(tc_skb_ext_tc);
@@ -1549,6 +1642,8 @@ static inline int __tcf_classify(struct sk_buff *skb,
 				 const struct tcf_proto *orig_tp,
 				 struct tcf_result *res,
 				 bool compat_mode,
+				 struct tcf_exts_miss_cookie_node *n,
+				 int act_index,
 				 u32 *last_executed_chain)
 {
 #ifdef CONFIG_NET_CLS_ACT
@@ -1560,13 +1655,40 @@ static inline int __tcf_classify(struct sk_buff *skb,
 #endif
 	for (; tp; tp = rcu_dereference_bh(tp->next)) {
 		__be16 protocol = skb_protocol(skb, false);
-		int err;
+		int err = 0;
 
-		if (tp->protocol != protocol &&
-		    tp->protocol != htons(ETH_P_ALL))
-			continue;
+		if (n) {
+			struct tcf_exts *exts;
 
-		err = tc_classify(skb, tp, res);
+			if (n->tp_prio != tp->prio)
+				continue;
+
+			/* We re-lookup the tp and chain based on index instead
+			 * of having hard refs and locks to them, so do a sanity
+			 * check if any of tp,chain,exts was replaced by the
+			 * time we got here with a cookie from hardware.
+			 */
+			if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
+				     !tp->ops->get_exts))
+				return TC_ACT_SHOT;
+
+			exts = tp->ops->get_exts(tp, n->handle);
+			if (unlikely(!exts || n->exts != exts))
+				return TC_ACT_SHOT;
+
+			n = NULL;
+#ifdef CONFIG_NET_CLS_ACT
+			err = tcf_action_exec(skb, exts->actions + act_index,
+					      exts->nr_actions - act_index,
+					      res);
+#endif
+		} else {
+			if (tp->protocol != protocol &&
+			    tp->protocol != htons(ETH_P_ALL))
+				continue;
+
+			err = tc_classify(skb, tp, res);
+		}
 #ifdef CONFIG_NET_CLS_ACT
 		if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
 			first_tp = orig_tp;
@@ -1582,6 +1704,9 @@ static inline int __tcf_classify(struct sk_buff *skb,
 			return err;
 	}
 
+	if (unlikely(n))
+		return TC_ACT_SHOT;
+
 	return TC_ACT_UNSPEC; /* signal: continue lookup */
 #ifdef CONFIG_NET_CLS_ACT
 reset:
@@ -1606,21 +1731,33 @@ int tcf_classify(struct sk_buff *skb,
 #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
 	u32 last_executed_chain = 0;
 
-	return __tcf_classify(skb, tp, tp, res, compat_mode,
+	return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
 			      &last_executed_chain);
 #else
 	u32 last_executed_chain = tp ? tp->chain->index : 0;
+	struct tcf_exts_miss_cookie_node *n = NULL;
 	const struct tcf_proto *orig_tp = tp;
 	struct tc_skb_ext *ext;
+	int act_index = 0;
 	int ret;
 
 	if (block) {
 		ext = skb_ext_find(skb, TC_SKB_EXT);
 
-		if (ext && ext->chain) {
+		if (ext && (ext->chain || ext->act_miss)) {
 			struct tcf_chain *fchain;
+			u32 chain = ext->chain;
+
+			if (ext->act_miss) {
+				n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
+								&act_index);
+				if (!n)
+					return TC_ACT_SHOT;
 
-			fchain = tcf_chain_lookup_rcu(block, ext->chain);
+				chain = n->chain_index;
+			}
+
+			fchain = tcf_chain_lookup_rcu(block, chain);
 			if (!fchain)
 				return TC_ACT_SHOT;
 
@@ -1632,7 +1769,7 @@ int tcf_classify(struct sk_buff *skb,
 		}
 	}
 
-	ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode,
+	ret = __tcf_classify(skb, tp, orig_tp, res, compat_mode, n, act_index,
 			     &last_executed_chain);
 
 	if (tc_skb_ext_tc_enabled()) {
@@ -3056,9 +3193,52 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
 	return skb->len;
 }
 
+int tcf_exts_init_ex(struct tcf_exts *exts, struct net *net, int action,
+		     int police, struct tcf_proto *tp, u32 handle,
+		     bool use_action_miss)
+{
+	int err = 0;
+
+#ifdef CONFIG_NET_CLS_ACT
+	exts->type = 0;
+	exts->nr_actions = 0;
+	/* Note: we do not own yet a reference on net.
+	 * This reference might be taken later from tcf_exts_get_net().
+	 */
+	exts->net = net;
+	exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
+				GFP_KERNEL);
+	if (!exts->actions)
+		return -ENOMEM;
+#endif
+
+	exts->action = action;
+	exts->police = police;
+
+	if (!use_action_miss)
+		return 0;
+
+#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+	err = tcf_exts_miss_cookie_base_alloc(exts, tp, handle);
+#endif
+	if (err)
+		goto err_miss_alloc;
+
+	return 0;
+
+err_miss_alloc:
+	tcf_exts_destroy(exts);
+	return err;
+}
+EXPORT_SYMBOL(tcf_exts_init_ex);
+
 void tcf_exts_destroy(struct tcf_exts *exts)
 {
 #ifdef CONFIG_NET_CLS_ACT
+#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+	tcf_exts_miss_cookie_base_destroy(exts);
+#endif
+
 	if (exts->actions) {
 		tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
 		kfree(exts->actions);
@@ -3547,6 +3727,7 @@ static int tc_setup_offload_act(struct tc_action *act,
 
 int tc_setup_action(struct flow_action *flow_action,
 		    struct tc_action *actions[],
+		    u32 miss_cookie_base,
 		    struct netlink_ext_ack *extack)
 {
 	int i, j, k, index, err = 0;
@@ -3577,6 +3758,8 @@ int tc_setup_action(struct flow_action *flow_action,
 		for (k = 0; k < index ; k++) {
 			entry[k].hw_stats = tc_act_hw_stats(act->hw_stats);
 			entry[k].hw_index = act->tcfa_index;
+			entry[k].miss_cookie =
+				tcf_exts_miss_cookie_get(miss_cookie_base, i);
 		}
 
 		j += index;
@@ -3599,10 +3782,15 @@ int tc_setup_offload_action(struct flow_action *flow_action,
 			    struct netlink_ext_ack *extack)
 {
 #ifdef CONFIG_NET_CLS_ACT
+	u32 miss_cookie_base;
+
 	if (!exts)
 		return 0;
 
-	return tc_setup_action(flow_action, exts->actions, extack);
+	miss_cookie_base = exts->miss_cookie_node ?
+			   exts->miss_cookie_node->miss_cookie_base : 0;
+	return tc_setup_action(flow_action, exts->actions, miss_cookie_base,
+			       extack);
 #else
 	return 0;
 #endif
@@ -3770,6 +3958,8 @@ static int __init tc_filter_init(void)
 	if (err)
 		goto err_register_pernet_subsys;
 
+	xa_init_flags(&tcf_exts_miss_cookies_xa, XA_FLAGS_ALLOC1);
+
 	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
 		      RTNL_FLAG_DOIT_UNLOCKED);
 	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
-- 
2.30.1

[PATCH net-next v4 2/6] net/sched: flower: Move filter handle initialization earlier

[Paul Blakey]

To support miss to action during hardware offload the filter's
handle is needed when setting up the actions (tcf_exts_init()),
and before offloading.

Move filter handle initialization earlier.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 net/sched/cls_flower.c | 62 ++++++++++++++++++++++++------------------
 1 file changed, 35 insertions(+), 27 deletions(-)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 0b15698b3531d..564b862870c71 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -2192,10 +2192,6 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 	INIT_LIST_HEAD(&fnew->hw_list);
 	refcount_set(&fnew->refcnt, 1);
 
-	err = tcf_exts_init(&fnew->exts, net, TCA_FLOWER_ACT, 0);
-	if (err < 0)
-		goto errout;
-
 	if (tb[TCA_FLOWER_FLAGS]) {
 		fnew->flags = nla_get_u32(tb[TCA_FLOWER_FLAGS]);
 
@@ -2205,15 +2201,45 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		}
 	}
 
+	if (!fold) {
+		spin_lock(&tp->lock);
+		if (!handle) {
+			handle = 1;
+			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
+					    INT_MAX, GFP_ATOMIC);
+		} else {
+			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
+					    handle, GFP_ATOMIC);
+
+			/* Filter with specified handle was concurrently
+			 * inserted after initial check in cls_api. This is not
+			 * necessarily an error if NLM_F_EXCL is not set in
+			 * message flags. Returning EAGAIN will cause cls_api to
+			 * try to update concurrently inserted rule.
+			 */
+			if (err == -ENOSPC)
+				err = -EAGAIN;
+		}
+		spin_unlock(&tp->lock);
+
+		if (err)
+			goto errout;
+	}
+	fnew->handle = handle;
+
+	err = tcf_exts_init(&fnew->exts, net, TCA_FLOWER_ACT, 0);
+	if (err < 0)
+		goto errout_idr;
+
 	err = fl_set_parms(net, tp, fnew, mask, base, tb, tca[TCA_RATE],
 			   tp->chain->tmplt_priv, flags, fnew->flags,
 			   extack);
 	if (err)
-		goto errout;
+		goto errout_idr;
 
 	err = fl_check_assign_mask(head, fnew, fold, mask);
 	if (err)
-		goto errout;
+		goto errout_idr;
 
 	err = fl_ht_insert_unique(fnew, fold, &in_ht);
 	if (err)
@@ -2279,29 +2305,9 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 		refcount_dec(&fold->refcnt);
 		__fl_put(fold);
 	} else {
-		if (handle) {
-			/* user specifies a handle and it doesn't exist */
-			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
-					    handle, GFP_ATOMIC);
-
-			/* Filter with specified handle was concurrently
-			 * inserted after initial check in cls_api. This is not
-			 * necessarily an error if NLM_F_EXCL is not set in
-			 * message flags. Returning EAGAIN will cause cls_api to
-			 * try to update concurrently inserted rule.
-			 */
-			if (err == -ENOSPC)
-				err = -EAGAIN;
-		} else {
-			handle = 1;
-			err = idr_alloc_u32(&head->handle_idr, fnew, &handle,
-					    INT_MAX, GFP_ATOMIC);
-		}
-		if (err)
-			goto errout_hw;
+		idr_replace(&head->handle_idr, fnew, fnew->handle);
 
 		refcount_inc(&fnew->refcnt);
-		fnew->handle = handle;
 		list_add_tail_rcu(&fnew->list, &fnew->mask->filters);
 		spin_unlock(&tp->lock);
 	}
@@ -2324,6 +2330,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 				       fnew->mask->filter_ht_params);
 errout_mask:
 	fl_mask_put(head, fnew->mask);
+errout_idr:
+	idr_remove(&head->handle_idr, fnew->handle);
 errout:
 	__fl_put(fnew);
 errout_tb:
-- 
2.30.1

[PATCH net-next v4 3/6] net/sched: flower: Support hardware miss to tc action

[Paul Blakey]

To support hardware miss to tc action in actions on the flower
classifier, implement the required getting of filter actions,
and setup filter exts (actions) miss by giving it the filter's
handle and actions.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
---
 net/sched/cls_flower.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 564b862870c71..5da7f6d02e5d0 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -534,6 +534,15 @@ static struct cls_fl_filter *__fl_get(struct cls_fl_head *head, u32 handle)
 	return f;
 }
 
+static struct tcf_exts *fl_get_exts(const struct tcf_proto *tp, u32 handle)
+{
+	struct cls_fl_head *head = rcu_dereference_bh(tp->root);
+	struct cls_fl_filter *f;
+
+	f = idr_find(&head->handle_idr, handle);
+	return f ? &f->exts : NULL;
+}
+
 static int __fl_delete(struct tcf_proto *tp, struct cls_fl_filter *f,
 		       bool *last, bool rtnl_held,
 		       struct netlink_ext_ack *extack)
@@ -2227,7 +2236,8 @@ static int fl_change(struct net *net, struct sk_buff *in_skb,
 	}
 	fnew->handle = handle;
 
-	err = tcf_exts_init(&fnew->exts, net, TCA_FLOWER_ACT, 0);
+	err = tcf_exts_init_ex(&fnew->exts, net, TCA_FLOWER_ACT, 0, tp, handle,
+			       !tc_skip_hw(fnew->flags));
 	if (err < 0)
 		goto errout_idr;
 
@@ -3449,6 +3459,7 @@ static struct tcf_proto_ops cls_fl_ops __read_mostly = {
 	.tmplt_create	= fl_tmplt_create,
 	.tmplt_destroy	= fl_tmplt_destroy,
 	.tmplt_dump	= fl_tmplt_dump,
+	.get_exts	= fl_get_exts,
 	.owner		= THIS_MODULE,
 	.flags		= TCF_PROTO_OPS_DOIT_UNLOCKED,
 };
-- 
2.30.1

[PATCH net-next v4 4/6] net/mlx5: Refactor tc miss handling to a single function

[Paul Blakey]

Move tc miss handling code to en_tc.c, and remove
duplicate code.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
---
 .../ethernet/mellanox/mlx5/core/en/rep/tc.c   | 225 ++----------------
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   |   4 +-
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   | 221 +++++++++++++++--
 .../net/ethernet/mellanox/mlx5/core/en_tc.h   |  11 +-
 4 files changed, 232 insertions(+), 229 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/rep/tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en/rep/tc.c
index b08339d986d5f..69ff212eaad86 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/rep/tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/rep/tc.c
@@ -1,7 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
 /* Copyright (c) 2020 Mellanox Technologies. */
 
-#include <net/dst_metadata.h>
 #include <linux/netdevice.h>
 #include <linux/if_macvlan.h>
 #include <linux/list.h>
@@ -665,235 +664,57 @@ void mlx5e_rep_tc_netdevice_event_unregister(struct mlx5e_rep_priv *rpriv)
 				 mlx5e_rep_indr_block_unbind);
 }
 
-static bool mlx5e_restore_tunnel(struct mlx5e_priv *priv, struct sk_buff *skb,
-				 struct mlx5e_tc_update_priv *tc_priv,
-				 u32 tunnel_id)
-{
-	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
-	struct tunnel_match_enc_opts enc_opts = {};
-	struct mlx5_rep_uplink_priv *uplink_priv;
-	struct mlx5e_rep_priv *uplink_rpriv;
-	struct metadata_dst *tun_dst;
-	struct tunnel_match_key key;
-	u32 tun_id, enc_opts_id;
-	struct net_device *dev;
-	int err;
-
-	enc_opts_id = tunnel_id & ENC_OPTS_BITS_MASK;
-	tun_id = tunnel_id >> ENC_OPTS_BITS;
-
-	if (!tun_id)
-		return true;
-
-	uplink_rpriv = mlx5_eswitch_get_uplink_priv(esw, REP_ETH);
-	uplink_priv = &uplink_rpriv->uplink_priv;
-
-	err = mapping_find(uplink_priv->tunnel_mapping, tun_id, &key);
-	if (err) {
-		netdev_dbg(priv->netdev,
-			   "Couldn't find tunnel for tun_id: %d, err: %d\n",
-			   tun_id, err);
-		return false;
-	}
-
-	if (enc_opts_id) {
-		err = mapping_find(uplink_priv->tunnel_enc_opts_mapping,
-				   enc_opts_id, &enc_opts);
-		if (err) {
-			netdev_dbg(priv->netdev,
-				   "Couldn't find tunnel (opts) for tun_id: %d, err: %d\n",
-				   enc_opts_id, err);
-			return false;
-		}
-	}
-
-	if (key.enc_control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
-		tun_dst = __ip_tun_set_dst(key.enc_ipv4.src, key.enc_ipv4.dst,
-					   key.enc_ip.tos, key.enc_ip.ttl,
-					   key.enc_tp.dst, TUNNEL_KEY,
-					   key32_to_tunnel_id(key.enc_key_id.keyid),
-					   enc_opts.key.len);
-	} else if (key.enc_control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
-		tun_dst = __ipv6_tun_set_dst(&key.enc_ipv6.src, &key.enc_ipv6.dst,
-					     key.enc_ip.tos, key.enc_ip.ttl,
-					     key.enc_tp.dst, 0, TUNNEL_KEY,
-					     key32_to_tunnel_id(key.enc_key_id.keyid),
-					     enc_opts.key.len);
-	} else {
-		netdev_dbg(priv->netdev,
-			   "Couldn't restore tunnel, unsupported addr_type: %d\n",
-			   key.enc_control.addr_type);
-		return false;
-	}
-
-	if (!tun_dst) {
-		netdev_dbg(priv->netdev, "Couldn't restore tunnel, no tun_dst\n");
-		return false;
-	}
-
-	tun_dst->u.tun_info.key.tp_src = key.enc_tp.src;
-
-	if (enc_opts.key.len)
-		ip_tunnel_info_opts_set(&tun_dst->u.tun_info,
-					enc_opts.key.data,
-					enc_opts.key.len,
-					enc_opts.key.dst_opt_type);
-
-	skb_dst_set(skb, (struct dst_entry *)tun_dst);
-	dev = dev_get_by_index(&init_net, key.filter_ifindex);
-	if (!dev) {
-		netdev_dbg(priv->netdev,
-			   "Couldn't find tunnel device with ifindex: %d\n",
-			   key.filter_ifindex);
-		return false;
-	}
-
-	/* Set fwd_dev so we do dev_put() after datapath */
-	tc_priv->fwd_dev = dev;
-
-	skb->dev = dev;
-
-	return true;
-}
-
-static bool mlx5e_restore_skb_chain(struct sk_buff *skb, u32 chain, u32 reg_c1,
-				    struct mlx5e_tc_update_priv *tc_priv)
-{
-	struct mlx5e_priv *priv = netdev_priv(skb->dev);
-	u32 tunnel_id = (reg_c1 >> ESW_TUN_OFFSET) & TUNNEL_ID_MASK;
-
-#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
-	if (chain) {
-		struct mlx5_rep_uplink_priv *uplink_priv;
-		struct mlx5e_rep_priv *uplink_rpriv;
-		struct tc_skb_ext *tc_skb_ext;
-		struct mlx5_eswitch *esw;
-		u32 zone_restore_id;
-
-		tc_skb_ext = tc_skb_ext_alloc(skb);
-		if (!tc_skb_ext) {
-			WARN_ON(1);
-			return false;
-		}
-		tc_skb_ext->chain = chain;
-		zone_restore_id = reg_c1 & ESW_ZONE_ID_MASK;
-		esw = priv->mdev->priv.eswitch;
-		uplink_rpriv = mlx5_eswitch_get_uplink_priv(esw, REP_ETH);
-		uplink_priv = &uplink_rpriv->uplink_priv;
-		if (!mlx5e_tc_ct_restore_flow(uplink_priv->ct_priv, skb,
-					      zone_restore_id))
-			return false;
-	}
-#endif /* CONFIG_NET_TC_SKB_EXT */
-
-	return mlx5e_restore_tunnel(priv, skb, tc_priv, tunnel_id);
-}
-
-static void mlx5_rep_tc_post_napi_receive(struct mlx5e_tc_update_priv *tc_priv)
-{
-	if (tc_priv->fwd_dev)
-		dev_put(tc_priv->fwd_dev);
-}
-
-static void mlx5e_restore_skb_sample(struct mlx5e_priv *priv, struct sk_buff *skb,
-				     struct mlx5_mapped_obj *mapped_obj,
-				     struct mlx5e_tc_update_priv *tc_priv)
-{
-	if (!mlx5e_restore_tunnel(priv, skb, tc_priv, mapped_obj->sample.tunnel_id)) {
-		netdev_dbg(priv->netdev,
-			   "Failed to restore tunnel info for sampled packet\n");
-		return;
-	}
-	mlx5e_tc_sample_skb(skb, mapped_obj);
-	mlx5_rep_tc_post_napi_receive(tc_priv);
-}
-
-static bool mlx5e_restore_skb_int_port(struct mlx5e_priv *priv, struct sk_buff *skb,
-				       struct mlx5_mapped_obj *mapped_obj,
-				       struct mlx5e_tc_update_priv *tc_priv,
-				       bool *forward_tx,
-				       u32 reg_c1)
-{
-	u32 tunnel_id = (reg_c1 >> ESW_TUN_OFFSET) & TUNNEL_ID_MASK;
-	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
-	struct mlx5_rep_uplink_priv *uplink_priv;
-	struct mlx5e_rep_priv *uplink_rpriv;
-
-	/* Tunnel restore takes precedence over int port restore */
-	if (tunnel_id)
-		return mlx5e_restore_tunnel(priv, skb, tc_priv, tunnel_id);
-
-	uplink_rpriv = mlx5_eswitch_get_uplink_priv(esw, REP_ETH);
-	uplink_priv = &uplink_rpriv->uplink_priv;
-
-	if (mlx5e_tc_int_port_dev_fwd(uplink_priv->int_port_priv, skb,
-				      mapped_obj->int_port_metadata, forward_tx)) {
-		/* Set fwd_dev for future dev_put */
-		tc_priv->fwd_dev = skb->dev;
-
-		return true;
-	}
-
-	return false;
-}
-
 void mlx5e_rep_tc_receive(struct mlx5_cqe64 *cqe, struct mlx5e_rq *rq,
 			  struct sk_buff *skb)
 {
-	u32 reg_c1 = be32_to_cpu(cqe->ft_metadata);
+	u32 reg_c1 = be32_to_cpu(cqe->ft_metadata), reg_c0, zone_restore_id, tunnel_id;
 	struct mlx5e_tc_update_priv tc_priv = {};
-	struct mlx5_mapped_obj mapped_obj;
+	struct mlx5_rep_uplink_priv *uplink_priv;
+	struct mlx5e_rep_priv *uplink_rpriv;
+	struct mlx5_tc_ct_priv *ct_priv;
+	struct mapping_ctx *mapping_ctx;
 	struct mlx5_eswitch *esw;
-	bool forward_tx = false;
 	struct mlx5e_priv *priv;
-	u32 reg_c0;
-	int err;
 
 	reg_c0 = (be32_to_cpu(cqe->sop_drop_qpn) & MLX5E_TC_FLOW_ID_MASK);
 	if (!reg_c0 || reg_c0 == MLX5_FS_DEFAULT_FLOW_TAG)
 		goto forward;
 
-	/* If reg_c0 is not equal to the default flow tag then skb->mark
+	/* If mapped_obj_id is not equal to the default flow tag then skb->mark
 	 * is not supported and must be reset back to 0.
 	 */
 	skb->mark = 0;
 
 	priv = netdev_priv(skb->dev);
 	esw = priv->mdev->priv.eswitch;
-	err = mapping_find(esw->offloads.reg_c0_obj_pool, reg_c0, &mapped_obj);
-	if (err) {
-		netdev_dbg(priv->netdev,
-			   "Couldn't find mapped object for reg_c0: %d, err: %d\n",
-			   reg_c0, err);
-		goto free_skb;
-	}
+	mapping_ctx = esw->offloads.reg_c0_obj_pool;
+	zone_restore_id = reg_c1 & ESW_ZONE_ID_MASK;
+	tunnel_id = (reg_c1 >> ESW_TUN_OFFSET) & TUNNEL_ID_MASK;
 
-	if (mapped_obj.type == MLX5_MAPPED_OBJ_CHAIN) {
-		if (!mlx5e_restore_skb_chain(skb, mapped_obj.chain, reg_c1, &tc_priv) &&
-		    !mlx5_ipsec_is_rx_flow(cqe))
-			goto free_skb;
-	} else if (mapped_obj.type == MLX5_MAPPED_OBJ_SAMPLE) {
-		mlx5e_restore_skb_sample(priv, skb, &mapped_obj, &tc_priv);
-		goto free_skb;
-	} else if (mapped_obj.type == MLX5_MAPPED_OBJ_INT_PORT_METADATA) {
-		if (!mlx5e_restore_skb_int_port(priv, skb, &mapped_obj, &tc_priv,
-						&forward_tx, reg_c1))
-			goto free_skb;
-	} else {
-		netdev_dbg(priv->netdev, "Invalid mapped object type: %d\n", mapped_obj.type);
+	uplink_rpriv = mlx5_eswitch_get_uplink_priv(esw, REP_ETH);
+	uplink_priv = &uplink_rpriv->uplink_priv;
+	ct_priv = uplink_priv->ct_priv;
+
+	if (!mlx5_ipsec_is_rx_flow(cqe) &&
+	    !mlx5e_tc_update_skb(cqe, skb, mapping_ctx, reg_c0, ct_priv, zone_restore_id, tunnel_id,
+				 &tc_priv))
 		goto free_skb;
-	}
 
 forward:
-	if (forward_tx)
+	if (tc_priv.skb_done)
+		goto free_skb;
+
+	if (tc_priv.forward_tx)
 		dev_queue_xmit(skb);
 	else
 		napi_gro_receive(rq->cq.napi, skb);
 
-	mlx5_rep_tc_post_napi_receive(&tc_priv);
+	if (tc_priv.fwd_dev)
+		dev_put(tc_priv.fwd_dev);
 
 	return;
 
 free_skb:
+	WARN_ON(tc_priv.fwd_dev);
 	dev_kfree_skb_any(skb);
 }
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
index 3df455f6b1685..e5faebb4c084e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c
@@ -1792,7 +1792,7 @@ static void mlx5e_handle_rx_cqe(struct mlx5e_rq *rq, struct mlx5_cqe64 *cqe)
 	mlx5e_complete_rx_cqe(rq, cqe, cqe_bcnt, skb);
 
 	if (mlx5e_cqe_regb_chain(cqe))
-		if (!mlx5e_tc_update_skb(cqe, skb)) {
+		if (!mlx5e_tc_update_skb_nic(cqe, skb)) {
 			dev_kfree_skb_any(skb);
 			goto free_wqe;
 		}
@@ -2256,7 +2256,7 @@ static void mlx5e_handle_rx_cqe_mpwrq(struct mlx5e_rq *rq, struct mlx5_cqe64 *cq
 	mlx5e_complete_rx_cqe(rq, cqe, cqe_bcnt, skb);
 
 	if (mlx5e_cqe_regb_chain(cqe))
-		if (!mlx5e_tc_update_skb(cqe, skb)) {
+		if (!mlx5e_tc_update_skb_nic(cqe, skb)) {
 			dev_kfree_skb_any(skb);
 			goto mpwrq_cqe_out;
 		}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 4e6f5caf8ab66..6275c451e32a9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -43,6 +43,7 @@
 #include <net/ipv6_stubs.h>
 #include <net/bareudp.h>
 #include <net/bonding.h>
+#include <net/dst_metadata.h>
 #include "en.h"
 #include "en/tc/post_act.h"
 #include "en_rep.h"
@@ -5562,47 +5563,221 @@ int mlx5e_setup_tc_block_cb(enum tc_setup_type type, void *type_data,
 	}
 }
 
-bool mlx5e_tc_update_skb(struct mlx5_cqe64 *cqe,
-			 struct sk_buff *skb)
+static bool mlx5e_tc_restore_tunnel(struct mlx5e_priv *priv, struct sk_buff *skb,
+				    struct mlx5e_tc_update_priv *tc_priv,
+				    u32 tunnel_id)
 {
-#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
-	u32 chain = 0, chain_tag, reg_b, zone_restore_id;
-	struct mlx5e_priv *priv = netdev_priv(skb->dev);
-	struct mlx5_mapped_obj mapped_obj;
-	struct tc_skb_ext *tc_skb_ext;
-	struct mlx5e_tc_table *tc;
+	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
+	struct tunnel_match_enc_opts enc_opts = {};
+	struct mlx5_rep_uplink_priv *uplink_priv;
+	struct mlx5e_rep_priv *uplink_rpriv;
+	struct metadata_dst *tun_dst;
+	struct tunnel_match_key key;
+	u32 tun_id, enc_opts_id;
+	struct net_device *dev;
 	int err;
 
-	reg_b = be32_to_cpu(cqe->ft_metadata);
-	tc = mlx5e_fs_get_tc(priv->fs);
-	chain_tag = reg_b & MLX5E_TC_TABLE_CHAIN_TAG_MASK;
+	enc_opts_id = tunnel_id & ENC_OPTS_BITS_MASK;
+	tun_id = tunnel_id >> ENC_OPTS_BITS;
 
-	err = mapping_find(tc->mapping, chain_tag, &mapped_obj);
+	if (!tun_id)
+		return true;
+
+	uplink_rpriv = mlx5_eswitch_get_uplink_priv(esw, REP_ETH);
+	uplink_priv = &uplink_rpriv->uplink_priv;
+
+	err = mapping_find(uplink_priv->tunnel_mapping, tun_id, &key);
 	if (err) {
 		netdev_dbg(priv->netdev,
-			   "Couldn't find chain for chain tag: %d, err: %d\n",
-			   chain_tag, err);
+			   "Couldn't find tunnel for tun_id: %d, err: %d\n",
+			   tun_id, err);
+		return false;
+	}
+
+	if (enc_opts_id) {
+		err = mapping_find(uplink_priv->tunnel_enc_opts_mapping,
+				   enc_opts_id, &enc_opts);
+		if (err) {
+			netdev_dbg(priv->netdev,
+				   "Couldn't find tunnel (opts) for tun_id: %d, err: %d\n",
+				   enc_opts_id, err);
+			return false;
+		}
+	}
+
+	if (key.enc_control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
+		tun_dst = __ip_tun_set_dst(key.enc_ipv4.src, key.enc_ipv4.dst,
+					   key.enc_ip.tos, key.enc_ip.ttl,
+					   key.enc_tp.dst, TUNNEL_KEY,
+					   key32_to_tunnel_id(key.enc_key_id.keyid),
+					   enc_opts.key.len);
+	} else if (key.enc_control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
+		tun_dst = __ipv6_tun_set_dst(&key.enc_ipv6.src, &key.enc_ipv6.dst,
+					     key.enc_ip.tos, key.enc_ip.ttl,
+					     key.enc_tp.dst, 0, TUNNEL_KEY,
+					     key32_to_tunnel_id(key.enc_key_id.keyid),
+					     enc_opts.key.len);
+	} else {
+		netdev_dbg(priv->netdev,
+			   "Couldn't restore tunnel, unsupported addr_type: %d\n",
+			   key.enc_control.addr_type);
 		return false;
 	}
 
-	if (mapped_obj.type == MLX5_MAPPED_OBJ_CHAIN) {
-		chain = mapped_obj.chain;
+	if (!tun_dst) {
+		netdev_dbg(priv->netdev, "Couldn't restore tunnel, no tun_dst\n");
+		return false;
+	}
+
+	tun_dst->u.tun_info.key.tp_src = key.enc_tp.src;
+
+	if (enc_opts.key.len)
+		ip_tunnel_info_opts_set(&tun_dst->u.tun_info,
+					enc_opts.key.data,
+					enc_opts.key.len,
+					enc_opts.key.dst_opt_type);
+
+	skb_dst_set(skb, (struct dst_entry *)tun_dst);
+	dev = dev_get_by_index(&init_net, key.filter_ifindex);
+	if (!dev) {
+		netdev_dbg(priv->netdev,
+			   "Couldn't find tunnel device with ifindex: %d\n",
+			   key.filter_ifindex);
+		return false;
+	}
+
+	/* Set fwd_dev so we do dev_put() after datapath */
+	tc_priv->fwd_dev = dev;
+
+	skb->dev = dev;
+
+	return true;
+}
+
+static bool mlx5e_tc_restore_skb_chain(struct sk_buff *skb, struct mlx5_tc_ct_priv *ct_priv,
+				       u32 chain, u32 zone_restore_id,
+				       u32 tunnel_id,  struct mlx5e_tc_update_priv *tc_priv)
+{
+	struct mlx5e_priv *priv = netdev_priv(skb->dev);
+	struct tc_skb_ext *tc_skb_ext;
+
+#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+	if (chain) {
+		if (!mlx5e_tc_ct_restore_flow(ct_priv, skb, zone_restore_id))
+			return false;
+
 		tc_skb_ext = tc_skb_ext_alloc(skb);
-		if (WARN_ON(!tc_skb_ext))
+		if (!tc_skb_ext) {
+			WARN_ON(1);
 			return false;
+		}
 
 		tc_skb_ext->chain = chain;
+	}
+#endif /* CONFIG_NET_TC_SKB_EXT */
 
-		zone_restore_id = (reg_b >> MLX5_REG_MAPPING_MOFFSET(NIC_ZONE_RESTORE_TO_REG)) &
-			ESW_ZONE_ID_MASK;
+	if (tc_priv)
+		return mlx5e_tc_restore_tunnel(priv, skb, tc_priv, tunnel_id);
 
-		if (!mlx5e_tc_ct_restore_flow(tc->ct, skb,
-					      zone_restore_id))
-			return false;
-	} else {
+	return true;
+}
+
+static void mlx5e_tc_restore_skb_sample(struct mlx5e_priv *priv, struct sk_buff *skb,
+					struct mlx5_mapped_obj *mapped_obj,
+					struct mlx5e_tc_update_priv *tc_priv)
+{
+	if (!mlx5e_tc_restore_tunnel(priv, skb, tc_priv, mapped_obj->sample.tunnel_id)) {
+		netdev_dbg(priv->netdev,
+			   "Failed to restore tunnel info for sampled packet\n");
+		return;
+	}
+	mlx5e_tc_sample_skb(skb, mapped_obj);
+}
+
+static bool mlx5e_tc_restore_skb_int_port(struct mlx5e_priv *priv, struct sk_buff *skb,
+					  struct mlx5_mapped_obj *mapped_obj,
+					  struct mlx5e_tc_update_priv *tc_priv,
+					  u32 tunnel_id)
+{
+	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
+	struct mlx5_rep_uplink_priv *uplink_priv;
+	struct mlx5e_rep_priv *uplink_rpriv;
+	bool forward_tx = false;
+
+	/* Tunnel restore takes precedence over int port restore */
+	if (tunnel_id)
+		return mlx5e_tc_restore_tunnel(priv, skb, tc_priv, tunnel_id);
+
+	uplink_rpriv = mlx5_eswitch_get_uplink_priv(esw, REP_ETH);
+	uplink_priv = &uplink_rpriv->uplink_priv;
+
+	if (mlx5e_tc_int_port_dev_fwd(uplink_priv->int_port_priv, skb,
+				      mapped_obj->int_port_metadata, &forward_tx)) {
+		/* Set fwd_dev for future dev_put */
+		tc_priv->fwd_dev = skb->dev;
+		tc_priv->forward_tx = forward_tx;
+
+		return true;
+	}
+
+	return false;
+}
+
+bool mlx5e_tc_update_skb(struct mlx5_cqe64 *cqe, struct sk_buff *skb,
+			 struct mapping_ctx *mapping_ctx, u32 mapped_obj_id,
+			 struct mlx5_tc_ct_priv *ct_priv,
+			 u32 zone_restore_id, u32 tunnel_id,
+			 struct mlx5e_tc_update_priv *tc_priv)
+{
+	struct mlx5e_priv *priv = netdev_priv(skb->dev);
+	struct mlx5_mapped_obj mapped_obj;
+	int err;
+
+	err = mapping_find(mapping_ctx, mapped_obj_id, &mapped_obj);
+	if (err) {
+		netdev_dbg(skb->dev,
+			   "Couldn't find mapped object for mapped_obj_id: %d, err: %d\n",
+			   mapped_obj_id, err);
+		return false;
+	}
+
+	switch (mapped_obj.type) {
+	case MLX5_MAPPED_OBJ_CHAIN:
+		return mlx5e_tc_restore_skb_chain(skb, ct_priv, mapped_obj.chain, zone_restore_id,
+						  tunnel_id, tc_priv);
+	case MLX5_MAPPED_OBJ_SAMPLE:
+		mlx5e_tc_restore_skb_sample(priv, skb, &mapped_obj, tc_priv);
+		tc_priv->skb_done = true;
+		return true;
+	case MLX5_MAPPED_OBJ_INT_PORT_METADATA:
+		return mlx5e_tc_restore_skb_int_port(priv, skb, &mapped_obj, tc_priv, tunnel_id);
+	default:
 		netdev_dbg(priv->netdev, "Invalid mapped object type: %d\n", mapped_obj.type);
 		return false;
 	}
+
+	return false;
+}
+
+bool mlx5e_tc_update_skb_nic(struct mlx5_cqe64 *cqe, struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+	struct mlx5e_priv *priv = netdev_priv(skb->dev);
+	u32 mapped_obj_id, reg_b, zone_restore_id;
+	struct mlx5_tc_ct_priv *ct_priv;
+	struct mapping_ctx *mapping_ctx;
+	struct mlx5e_tc_table *tc;
+
+	reg_b = be32_to_cpu(cqe->ft_metadata);
+	tc = mlx5e_fs_get_tc(priv->fs);
+	mapped_obj_id = reg_b & MLX5E_TC_TABLE_CHAIN_TAG_MASK;
+	zone_restore_id = (reg_b >> MLX5_REG_MAPPING_MOFFSET(NIC_ZONE_RESTORE_TO_REG)) &
+			  ESW_ZONE_ID_MASK;
+	ct_priv = tc->ct;
+	mapping_ctx = tc->mapping;
+
+	return mlx5e_tc_update_skb(cqe, skb, mapping_ctx, mapped_obj_id, ct_priv, zone_restore_id,
+				   0, NULL);
 #endif /* CONFIG_NET_TC_SKB_EXT */
 
 	return true;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
index ce516dc7f3fde..4fa5d4e024cd6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
@@ -59,6 +59,8 @@ int mlx5e_tc_num_filters(struct mlx5e_priv *priv, unsigned long flags);
 
 struct mlx5e_tc_update_priv {
 	struct net_device *fwd_dev;
+	bool skb_done;
+	bool forward_tx;
 };
 
 struct mlx5_nic_flow_attr {
@@ -386,14 +388,19 @@ static inline bool mlx5e_cqe_regb_chain(struct mlx5_cqe64 *cqe)
 	return false;
 }
 
-bool mlx5e_tc_update_skb(struct mlx5_cqe64 *cqe, struct sk_buff *skb);
+bool mlx5e_tc_update_skb_nic(struct mlx5_cqe64 *cqe, struct sk_buff *skb);
+bool mlx5e_tc_update_skb(struct mlx5_cqe64 *cqe, struct sk_buff *skb,
+			 struct mapping_ctx *mapping_ctx, u32 mapped_obj_id,
+			 struct mlx5_tc_ct_priv *ct_priv,
+			 u32 zone_restore_id, u32 tunnel_id,
+			 struct mlx5e_tc_update_priv *tc_priv);
 #else /* CONFIG_MLX5_CLS_ACT */
 static inline struct mlx5e_tc_table *mlx5e_tc_table_alloc(void) { return NULL; }
 static inline void mlx5e_tc_table_free(struct mlx5e_tc_table *tc) {}
 static inline bool mlx5e_cqe_regb_chain(struct mlx5_cqe64 *cqe)
 { return false; }
 static inline bool
-mlx5e_tc_update_skb(struct mlx5_cqe64 *cqe, struct sk_buff *skb)
+mlx5e_tc_update_skb_nic(struct mlx5_cqe64 *cqe, struct sk_buff *skb)
 { return true; }
 #endif
 
-- 
2.30.1

[PATCH net-next v4 5/6] net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG

[Paul Blakey]

This reg usage is always a mapped object, not necessarily
containing chain info.

Rename to properly convey what it stores.
This patch doesn't change any functionality.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
---
 .../net/ethernet/mellanox/mlx5/core/en/tc/sample.c |  2 +-
 drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c |  2 +-
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c    |  6 +++---
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.h    |  4 ++--
 .../ethernet/mellanox/mlx5/core/lib/fs_chains.c    | 14 +++++++-------
 5 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c
index f2c2c752bd1c3..558a776359af6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc/sample.c
@@ -237,7 +237,7 @@ sample_modify_hdr_get(struct mlx5_core_dev *mdev, u32 obj_id,
 	int err;
 
 	err = mlx5e_tc_match_to_reg_set(mdev, mod_acts, MLX5_FLOW_NAMESPACE_FDB,
-					CHAIN_TO_REG, obj_id);
+					MAPPED_OBJ_TO_REG, obj_id);
 	if (err)
 		goto err_set_regc0;
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
index 313df8232db70..e1a2861cc13ba 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
@@ -1871,7 +1871,7 @@ __mlx5_tc_ct_flow_offload(struct mlx5_tc_ct_priv *ct_priv,
 	ct_flow->chain_mapping = chain_mapping;
 
 	err = mlx5e_tc_match_to_reg_set(priv->mdev, pre_mod_acts, ct_priv->ns_type,
-					CHAIN_TO_REG, chain_mapping);
+					MAPPED_OBJ_TO_REG, chain_mapping);
 	if (err) {
 		ct_dbg("Failed to set chain register mapping");
 		goto err_mapping;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 6275c451e32a9..0bccc23f97ff0 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -105,7 +105,7 @@ struct mlx5e_tc_table {
 };
 
 struct mlx5e_tc_attr_to_reg_mapping mlx5e_tc_attr_to_reg_mappings[] = {
-	[CHAIN_TO_REG] = {
+	[MAPPED_OBJ_TO_REG] = {
 		.mfield = MLX5_ACTION_IN_FIELD_METADATA_REG_C_0,
 		.moffset = 0,
 		.mlen = 16,
@@ -132,7 +132,7 @@ struct mlx5e_tc_attr_to_reg_mapping mlx5e_tc_attr_to_reg_mappings[] = {
 	 * into reg_b that is passed to SW since we don't
 	 * jump between steering domains.
 	 */
-	[NIC_CHAIN_TO_REG] = {
+	[NIC_MAPPED_OBJ_TO_REG] = {
 		.mfield = MLX5_ACTION_IN_FIELD_METADATA_REG_B,
 		.moffset = 0,
 		.mlen = 16,
@@ -1585,7 +1585,7 @@ mlx5e_tc_offload_to_slow_path(struct mlx5_eswitch *esw,
 		goto err_get_chain;
 
 	err = mlx5e_tc_match_to_reg_set(esw->dev, &mod_acts, MLX5_FLOW_NAMESPACE_FDB,
-					CHAIN_TO_REG, chain_mapping);
+					MAPPED_OBJ_TO_REG, chain_mapping);
 	if (err)
 		goto err_reg_set;
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
index 4fa5d4e024cd6..eb985f7bdea75 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
@@ -229,7 +229,7 @@ void mlx5e_tc_update_neigh_used_value(struct mlx5e_neigh_hash_entry *nhe);
 void mlx5e_tc_reoffload_flows_work(struct work_struct *work);
 
 enum mlx5e_tc_attr_to_reg {
-	CHAIN_TO_REG,
+	MAPPED_OBJ_TO_REG,
 	VPORT_TO_REG,
 	TUNNEL_TO_REG,
 	CTSTATE_TO_REG,
@@ -238,7 +238,7 @@ enum mlx5e_tc_attr_to_reg {
 	MARK_TO_REG,
 	LABELS_TO_REG,
 	FTEID_TO_REG,
-	NIC_CHAIN_TO_REG,
+	NIC_MAPPED_OBJ_TO_REG,
 	NIC_ZONE_RESTORE_TO_REG,
 	PACKET_COLOR_TO_REG,
 };
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/fs_chains.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/fs_chains.c
index df58cba37930a..81ed91fee59b9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/fs_chains.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/fs_chains.c
@@ -214,7 +214,7 @@ create_chain_restore(struct fs_chain *chain)
 	struct mlx5_eswitch *esw = chain->chains->dev->priv.eswitch;
 	u8 modact[MLX5_UN_SZ_BYTES(set_add_copy_action_in_auto)] = {};
 	struct mlx5_fs_chains *chains = chain->chains;
-	enum mlx5e_tc_attr_to_reg chain_to_reg;
+	enum mlx5e_tc_attr_to_reg mapped_obj_to_reg;
 	struct mlx5_modify_hdr *mod_hdr;
 	u32 index;
 	int err;
@@ -242,7 +242,7 @@ create_chain_restore(struct fs_chain *chain)
 	chain->id = index;
 
 	if (chains->ns == MLX5_FLOW_NAMESPACE_FDB) {
-		chain_to_reg = CHAIN_TO_REG;
+		mapped_obj_to_reg = MAPPED_OBJ_TO_REG;
 		chain->restore_rule = esw_add_restore_rule(esw, chain->id);
 		if (IS_ERR(chain->restore_rule)) {
 			err = PTR_ERR(chain->restore_rule);
@@ -253,7 +253,7 @@ create_chain_restore(struct fs_chain *chain)
 		 * since we write the metadata to reg_b
 		 * that is passed to SW directly.
 		 */
-		chain_to_reg = NIC_CHAIN_TO_REG;
+		mapped_obj_to_reg = NIC_MAPPED_OBJ_TO_REG;
 	} else {
 		err = -EINVAL;
 		goto err_rule;
@@ -261,12 +261,12 @@ create_chain_restore(struct fs_chain *chain)
 
 	MLX5_SET(set_action_in, modact, action_type, MLX5_ACTION_TYPE_SET);
 	MLX5_SET(set_action_in, modact, field,
-		 mlx5e_tc_attr_to_reg_mappings[chain_to_reg].mfield);
+		 mlx5e_tc_attr_to_reg_mappings[mapped_obj_to_reg].mfield);
 	MLX5_SET(set_action_in, modact, offset,
-		 mlx5e_tc_attr_to_reg_mappings[chain_to_reg].moffset);
+		 mlx5e_tc_attr_to_reg_mappings[mapped_obj_to_reg].moffset);
 	MLX5_SET(set_action_in, modact, length,
-		 mlx5e_tc_attr_to_reg_mappings[chain_to_reg].mlen == 32 ?
-		 0 : mlx5e_tc_attr_to_reg_mappings[chain_to_reg].mlen);
+		 mlx5e_tc_attr_to_reg_mappings[mapped_obj_to_reg].mlen == 32 ?
+		 0 : mlx5e_tc_attr_to_reg_mappings[mapped_obj_to_reg].mlen);
 	MLX5_SET(set_action_in, modact, data, chain->id);
 	mod_hdr = mlx5_modify_header_alloc(chains->dev, chains->ns,
 					   1, modact);
-- 
2.30.1

[PATCH net-next v4 6/6] net/mlx5: TC, Set CT miss to the specific ct action instance

[Paul Blakey]

Currently, CT misses restore the missed chain on the tc skb extension so
tc will continue from the relevant chain. Instead, restore the CT action's
miss cookie on the extension, which will instruct tc to continue from the
this specific CT action instance on the relevant filter's action list.

Map the CT action's miss_cookie to a new miss object (ACT_MISS), and use
this miss mapping instead of the current chain miss object (CHAIN_MISS)
for CT action misses.

To restore this new miss mapping value, add a RX restore rule for each
such mapping value.

Signed-off-by: Paul Blakey <paulb@nvidia.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Oz Sholmo <ozsh@nvidia.com>
---
 .../ethernet/mellanox/mlx5/core/en/tc_ct.c    | 32 +++++-----
 .../ethernet/mellanox/mlx5/core/en/tc_ct.h    |  2 +
 .../net/ethernet/mellanox/mlx5/core/en_tc.c   | 61 ++++++++++++++++---
 .../net/ethernet/mellanox/mlx5/core/en_tc.h   |  6 ++
 .../net/ethernet/mellanox/mlx5/core/eswitch.h |  2 +
 5 files changed, 79 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
index e1a2861cc13ba..71d8a906add97 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
@@ -59,6 +59,7 @@ struct mlx5_tc_ct_debugfs {
 
 struct mlx5_tc_ct_priv {
 	struct mlx5_core_dev *dev;
+	struct mlx5e_priv *priv;
 	const struct net_device *netdev;
 	struct mod_hdr_tbl *mod_hdr_tbl;
 	struct xarray tuple_ids;
@@ -85,7 +86,6 @@ struct mlx5_ct_flow {
 	struct mlx5_flow_attr *pre_ct_attr;
 	struct mlx5_flow_handle *pre_ct_rule;
 	struct mlx5_ct_ft *ft;
-	u32 chain_mapping;
 };
 
 struct mlx5_ct_zone_rule {
@@ -1441,6 +1441,7 @@ mlx5_tc_ct_parse_action(struct mlx5_tc_ct_priv *priv,
 	attr->ct_attr.zone = act->ct.zone;
 	attr->ct_attr.ct_action = act->ct.action;
 	attr->ct_attr.nf_ft = act->ct.flow_table;
+	attr->ct_attr.act_miss_cookie = act->miss_cookie;
 
 	return 0;
 }
@@ -1778,7 +1779,7 @@ mlx5_tc_ct_del_ft_cb(struct mlx5_tc_ct_priv *ct_priv, struct mlx5_ct_ft *ft)
  *	+ ft prio (tc chain)  +
  *	+ original match      +
  *	+---------------------+
- *		 | set chain miss mapping
+ *		 | set act_miss_cookie mapping
  *		 | set fte_id
  *		 | set tunnel_id
  *		 | do decap
@@ -1823,7 +1824,7 @@ __mlx5_tc_ct_flow_offload(struct mlx5_tc_ct_priv *ct_priv,
 	struct mlx5_flow_attr *pre_ct_attr;
 	struct mlx5_modify_hdr *mod_hdr;
 	struct mlx5_ct_flow *ct_flow;
-	int chain_mapping = 0, err;
+	int act_miss_mapping = 0, err;
 	struct mlx5_ct_ft *ft;
 	u16 zone;
 
@@ -1858,22 +1859,18 @@ __mlx5_tc_ct_flow_offload(struct mlx5_tc_ct_priv *ct_priv,
 	pre_ct_attr->action |= MLX5_FLOW_CONTEXT_ACTION_FWD_DEST |
 			       MLX5_FLOW_CONTEXT_ACTION_MOD_HDR;
 
-	/* Write chain miss tag for miss in ct table as we
-	 * don't go though all prios of this chain as normal tc rules
-	 * miss.
-	 */
-	err = mlx5_chains_get_chain_mapping(ct_priv->chains, attr->chain,
-					    &chain_mapping);
+	err = mlx5e_tc_action_miss_mapping_get(ct_priv->priv, attr, attr->ct_attr.act_miss_cookie,
+					       &act_miss_mapping);
 	if (err) {
-		ct_dbg("Failed to get chain register mapping for chain");
-		goto err_get_chain;
+		ct_dbg("Failed to get register mapping for act miss");
+		goto err_get_act_miss;
 	}
-	ct_flow->chain_mapping = chain_mapping;
+	attr->ct_attr.act_miss_mapping = act_miss_mapping;
 
 	err = mlx5e_tc_match_to_reg_set(priv->mdev, pre_mod_acts, ct_priv->ns_type,
-					MAPPED_OBJ_TO_REG, chain_mapping);
+					MAPPED_OBJ_TO_REG, act_miss_mapping);
 	if (err) {
-		ct_dbg("Failed to set chain register mapping");
+		ct_dbg("Failed to set act miss register mapping");
 		goto err_mapping;
 	}
 
@@ -1937,8 +1934,8 @@ __mlx5_tc_ct_flow_offload(struct mlx5_tc_ct_priv *ct_priv,
 	mlx5_modify_header_dealloc(priv->mdev, pre_ct_attr->modify_hdr);
 err_mapping:
 	mlx5e_mod_hdr_dealloc(pre_mod_acts);
-	mlx5_chains_put_chain_mapping(ct_priv->chains, ct_flow->chain_mapping);
-err_get_chain:
+	mlx5e_tc_action_miss_mapping_put(ct_priv->priv, attr, act_miss_mapping);
+err_get_act_miss:
 	kfree(ct_flow->pre_ct_attr);
 err_alloc_pre:
 	mlx5_tc_ct_del_ft_cb(ct_priv, ft);
@@ -1977,7 +1974,7 @@ __mlx5_tc_ct_delete_flow(struct mlx5_tc_ct_priv *ct_priv,
 	mlx5_tc_rule_delete(priv, ct_flow->pre_ct_rule, pre_ct_attr);
 	mlx5_modify_header_dealloc(priv->mdev, pre_ct_attr->modify_hdr);
 
-	mlx5_chains_put_chain_mapping(ct_priv->chains, ct_flow->chain_mapping);
+	mlx5e_tc_action_miss_mapping_put(ct_priv->priv, attr, attr->ct_attr.act_miss_mapping);
 	mlx5_tc_ct_del_ft_cb(ct_priv, ct_flow->ft);
 
 	kfree(ct_flow->pre_ct_attr);
@@ -2157,6 +2154,7 @@ mlx5_tc_ct_init(struct mlx5e_priv *priv, struct mlx5_fs_chains *chains,
 	}
 
 	spin_lock_init(&ct_priv->ht_lock);
+	ct_priv->priv = priv;
 	ct_priv->ns_type = ns_type;
 	ct_priv->chains = chains;
 	ct_priv->netdev = priv->netdev;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.h b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.h
index 5bbd6b92840fb..5c5ddaa83055d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.h
@@ -28,6 +28,8 @@ struct mlx5_ct_attr {
 	struct mlx5_ct_flow *ct_flow;
 	struct nf_flowtable *nf_ft;
 	u32 ct_labels_id;
+	u32 act_miss_mapping;
+	u64 act_miss_cookie;
 };
 
 #define zone_to_reg_ct {\
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 0bccc23f97ff0..8c7125844e619 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -3801,6 +3801,7 @@ mlx5e_clone_flow_attr_for_post_act(struct mlx5_flow_attr *attr,
 	attr2->parse_attr = parse_attr;
 	attr2->dest_chain = 0;
 	attr2->dest_ft = NULL;
+	attr2->act_id_restore_rule = NULL;
 
 	if (ns_type == MLX5_FLOW_NAMESPACE_FDB) {
 		attr2->esw_attr->out_count = 0;
@@ -5654,15 +5655,18 @@ static bool mlx5e_tc_restore_tunnel(struct mlx5e_priv *priv, struct sk_buff *skb
 	return true;
 }
 
-static bool mlx5e_tc_restore_skb_chain(struct sk_buff *skb, struct mlx5_tc_ct_priv *ct_priv,
-				       u32 chain, u32 zone_restore_id,
-				       u32 tunnel_id,  struct mlx5e_tc_update_priv *tc_priv)
+static bool mlx5e_tc_restore_skb_tc_meta(struct sk_buff *skb, struct mlx5_tc_ct_priv *ct_priv,
+					 struct mlx5_mapped_obj *mapped_obj, u32 zone_restore_id,
+					 u32 tunnel_id,  struct mlx5e_tc_update_priv *tc_priv)
 {
+	u32 chain = mapped_obj->type == MLX5_MAPPED_OBJ_CHAIN ? mapped_obj->chain : 0;
+	u64 act_miss_cookie = mapped_obj->type == MLX5_MAPPED_OBJ_ACT_MISS ?
+			      mapped_obj->act_miss_cookie : 0;
 	struct mlx5e_priv *priv = netdev_priv(skb->dev);
 	struct tc_skb_ext *tc_skb_ext;
 
 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
-	if (chain) {
+	if (chain || act_miss_cookie) {
 		if (!mlx5e_tc_ct_restore_flow(ct_priv, skb, zone_restore_id))
 			return false;
 
@@ -5672,7 +5676,12 @@ static bool mlx5e_tc_restore_skb_chain(struct sk_buff *skb, struct mlx5_tc_ct_pr
 			return false;
 		}
 
-		tc_skb_ext->chain = chain;
+		if (act_miss_cookie) {
+			tc_skb_ext->act_miss_cookie = act_miss_cookie;
+			tc_skb_ext->act_miss = 1;
+		} else {
+			tc_skb_ext->chain = chain;
+		}
 	}
 #endif /* CONFIG_NET_TC_SKB_EXT */
 
@@ -5743,8 +5752,9 @@ bool mlx5e_tc_update_skb(struct mlx5_cqe64 *cqe, struct sk_buff *skb,
 
 	switch (mapped_obj.type) {
 	case MLX5_MAPPED_OBJ_CHAIN:
-		return mlx5e_tc_restore_skb_chain(skb, ct_priv, mapped_obj.chain, zone_restore_id,
-						  tunnel_id, tc_priv);
+	case MLX5_MAPPED_OBJ_ACT_MISS:
+		return mlx5e_tc_restore_skb_tc_meta(skb, ct_priv, &mapped_obj, zone_restore_id,
+						    tunnel_id, tc_priv);
 	case MLX5_MAPPED_OBJ_SAMPLE:
 		mlx5e_tc_restore_skb_sample(priv, skb, &mapped_obj, tc_priv);
 		tc_priv->skb_done = true;
@@ -5782,3 +5792,40 @@ bool mlx5e_tc_update_skb_nic(struct mlx5_cqe64 *cqe, struct sk_buff *skb)
 
 	return true;
 }
+
+int mlx5e_tc_action_miss_mapping_get(struct mlx5e_priv *priv, struct mlx5_flow_attr *attr,
+				     u64 act_miss_cookie, u32 *act_miss_mapping)
+{
+	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
+	struct mlx5_mapped_obj mapped_obj = {};
+	struct mapping_ctx *ctx;
+	int err;
+
+	ctx = esw->offloads.reg_c0_obj_pool;
+
+	mapped_obj.type = MLX5_MAPPED_OBJ_ACT_MISS;
+	mapped_obj.act_miss_cookie = act_miss_cookie;
+	err = mapping_add(ctx, &mapped_obj, act_miss_mapping);
+	if (err)
+		return err;
+
+	attr->act_id_restore_rule = esw_add_restore_rule(esw, *act_miss_mapping);
+	if (IS_ERR(attr->act_id_restore_rule))
+		goto err_rule;
+
+	return 0;
+
+err_rule:
+	mapping_remove(ctx, *act_miss_mapping);
+	return err;
+}
+
+void mlx5e_tc_action_miss_mapping_put(struct mlx5e_priv *priv, struct mlx5_flow_attr *attr,
+				      u32 act_miss_mapping)
+{
+	struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
+	struct mapping_ctx *ctx = esw->offloads.reg_c0_obj_pool;
+
+	mlx5_del_flow_rules(attr->act_id_restore_rule);
+	mapping_remove(ctx, act_miss_mapping);
+}
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
index eb985f7bdea75..60bff94ba2b62 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.h
@@ -101,6 +101,7 @@ struct mlx5_flow_attr {
 	struct mlx5_flow_attr *branch_true;
 	struct mlx5_flow_attr *branch_false;
 	struct mlx5_flow_attr *jumping_attr;
+	struct mlx5_flow_handle *act_id_restore_rule;
 	/* keep this union last */
 	union {
 		DECLARE_FLEX_ARRAY(struct mlx5_esw_flow_attr, esw_attr);
@@ -404,4 +405,9 @@ mlx5e_tc_update_skb_nic(struct mlx5_cqe64 *cqe, struct sk_buff *skb)
 { return true; }
 #endif
 
+int mlx5e_tc_action_miss_mapping_get(struct mlx5e_priv *priv, struct mlx5_flow_attr *attr,
+				     u64 act_miss_cookie, u32 *act_miss_mapping);
+void mlx5e_tc_action_miss_mapping_put(struct mlx5e_priv *priv, struct mlx5_flow_attr *attr,
+				      u32 act_miss_mapping);
+
 #endif /* __MLX5_EN_TC_H__ */
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
index 92644fbb50816..6aa48c003ba63 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.h
@@ -52,12 +52,14 @@ enum mlx5_mapped_obj_type {
 	MLX5_MAPPED_OBJ_CHAIN,
 	MLX5_MAPPED_OBJ_SAMPLE,
 	MLX5_MAPPED_OBJ_INT_PORT_METADATA,
+	MLX5_MAPPED_OBJ_ACT_MISS,
 };
 
 struct mlx5_mapped_obj {
 	enum mlx5_mapped_obj_type type;
 	union {
 		u32 chain;
+		u64 act_miss_cookie;
 		struct {
 			u32 group_id;
 			u32 rate;
-- 
2.30.1

Re: [PATCH net-next v4 1/6] net/sched: cls_api: Support hardware miss to tc action

[Simon Horman]

On Sun, Jan 22, 2023 at 04:55:07PM +0200, Paul Blakey wrote:
> For drivers to support partial offload of a filter's action list,
> add support for action miss to specify an action instance to
> continue from in sw.
> 
> CT action in particular can't be fully offloaded, as new connections
> need to be handled in software. This imposes other limitations on
> the actions that can be offloaded together with the CT action, such
> as packet modifications.
> 
> Assign each action on a filter's action list a unique miss_cookie
> which drivers can then use to fill action_miss part of the tc skb
> extension. On getting back this miss_cookie, find the action
> instance with relevant cookie and continue classifying from there.
> 
> Signed-off-by: Paul Blakey <paulb@nvidia.com>
> Reviewed-by: Jiri Pirko <jiri@nvidia.com>

...

> diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
> index 4cabb32a2ad94..9ef85cf9b5328 100644
> --- a/include/net/pkt_cls.h
> +++ b/include/net/pkt_cls.h

...

> @@ -240,21 +243,11 @@ struct tcf_exts {
>  static inline int tcf_exts_init(struct tcf_exts *exts, struct net *net,
>  				int action, int police)
>  {
> -#ifdef CONFIG_NET_CLS_ACT
> -	exts->type = 0;
> -	exts->nr_actions = 0;
> -	/* Note: we do not own yet a reference on net.
> -	 * This reference might be taken later from tcf_exts_get_net().
> -	 */
> -	exts->net = net;
> -	exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
> -				GFP_KERNEL);
> -	if (!exts->actions)
> -		return -ENOMEM;
> +#ifdef CONFIG_NET_CLS
> +	return tcf_exts_init_ex(exts, net, action, police, NULL, 0, false);
> +#else
> +	return -EOPNOTSUPP;
>  #endif

nit: I think it would be nicer if there was a dummy implementation
of tcf_exts_init_ex for the !CONFIG_NET_CLS case and #ifdefs
could disappear from tcf_exts_init() entirely.

Likewise, elsewhere in this patch there seems to be new #if/#ifdefs
Which may be in keeping with the style of this file. But I also
think it's a style we ought to be moving away from.

> -	exts->action = action;
> -	exts->police = police;
> -	return 0;
>  }
>  
>  /* Return false if the netns is being destroyed in cleanup_net(). Callers

...

> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
> index 5b4a95e8a1ee0..46524ae353c5a 100644
> --- a/net/sched/cls_api.c
> +++ b/net/sched/cls_api.c

...

> +static struct tcf_exts_miss_cookie_node *
> +tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
> +{
> +	union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
> +
> +	*act_index = mc.act_index;
> +	return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
> +}
> +#endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
> +
> +static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
> +{
> +	union tcf_exts_miss_cookie mc = { .act_index = act_index, };
> +
> +	if (!miss_cookie_base)
> +		return 0;

nit: perhaps the compiler optimises this out, or it is otherwise
unimportant,
but doesn't the assignment
of mc zero it's fields, other than .act_index only for:

1. Any assignment of mc to be unused in the !miss_cookie_base case
2. mc.miss_cookie_base to be reassigned, otherwise

FWIIW, I might have gone for something more like this (*untested*).

	union tcf_exts_miss_cookie mc;

	if (!miss_cookie_base)
		return 0;

	mc.act_index = act_index;
	mc.miss_cookie_base = miss_cookie_base;

	return mc.miss_cookie;

> +
> +	mc.miss_cookie_base = miss_cookie_base;
> +	return mc.miss_cookie;
> +}
> +
>  #ifdef CONFIG_NET_CLS_ACT
>  DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
>  EXPORT_SYMBOL(tc_skb_ext_tc);
> @@ -1549,6 +1642,8 @@ static inline int __tcf_classify(struct sk_buff *skb,
>  				 const struct tcf_proto *orig_tp,
>  				 struct tcf_result *res,
>  				 bool compat_mode,
> +				 struct tcf_exts_miss_cookie_node *n,
> +				 int act_index,
>  				 u32 *last_executed_chain)
>  {
>  #ifdef CONFIG_NET_CLS_ACT
> @@ -1560,13 +1655,40 @@ static inline int __tcf_classify(struct sk_buff *skb,
>  #endif
>  	for (; tp; tp = rcu_dereference_bh(tp->next)) {
>  		__be16 protocol = skb_protocol(skb, false);
> -		int err;
> +		int err = 0;
>  
> -		if (tp->protocol != protocol &&
> -		    tp->protocol != htons(ETH_P_ALL))
> -			continue;
> +		if (n) {
> +			struct tcf_exts *exts;
>  
> -		err = tc_classify(skb, tp, res);
> +			if (n->tp_prio != tp->prio)
> +				continue;
> +
> +			/* We re-lookup the tp and chain based on index instead
> +			 * of having hard refs and locks to them, so do a sanity
> +			 * check if any of tp,chain,exts was replaced by the
> +			 * time we got here with a cookie from hardware.
> +			 */
> +			if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
> +				     !tp->ops->get_exts))
> +				return TC_ACT_SHOT;
> +
> +			exts = tp->ops->get_exts(tp, n->handle);

I see that this is probably safe, but it's not entirely obvious
that tp->ops->get_exts will never by NULL here.

1) It is invariant on n, which is set in a different function and is in turn
2) invariant on ext->act_miss being set, several patches away, in the driver.
3) Which is lastly invariant on being a code path relating to for
   hardware offload of a classifier where tp->ops->get_exts is defined.

Or perhaps I mixed it up somehow. But I do think at a minimum this
ought to be documented.

Which brings me to a more central concern with this series: it's very
invasive and sets up a complex relationship between the core and the
driver. Is this the right abstraction for the problem at hand?

> +			if (unlikely(!exts || n->exts != exts))
> +				return TC_ACT_SHOT;
> +
> +			n = NULL;
> +#ifdef CONFIG_NET_CLS_ACT
> +			err = tcf_action_exec(skb, exts->actions + act_index,
> +					      exts->nr_actions - act_index,
> +					      res);
> +#endif
> +		} else {
> +			if (tp->protocol != protocol &&
> +			    tp->protocol != htons(ETH_P_ALL))
> +				continue;
> +
> +			err = tc_classify(skb, tp, res);
> +		}
>  #ifdef CONFIG_NET_CLS_ACT
>  		if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
>  			first_tp = orig_tp;

...

> @@ -1606,21 +1731,33 @@ int tcf_classify(struct sk_buff *skb,
>  #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
>  	u32 last_executed_chain = 0;
>  
> -	return __tcf_classify(skb, tp, tp, res, compat_mode,
> +	return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
>  			      &last_executed_chain);
>  #else
>  	u32 last_executed_chain = tp ? tp->chain->index : 0;
> +	struct tcf_exts_miss_cookie_node *n = NULL;
>  	const struct tcf_proto *orig_tp = tp;
>  	struct tc_skb_ext *ext;
> +	int act_index = 0;
>  	int ret;
>  
>  	if (block) {
>  		ext = skb_ext_find(skb, TC_SKB_EXT);
>  
> -		if (ext && ext->chain) {
> +		if (ext && (ext->chain || ext->act_miss)) {
>  			struct tcf_chain *fchain;
> +			u32 chain = ext->chain;

nit: ext->chain seems to only be used once, as it was before this patch.
Perhaps the chain local variable is an artifact of development
and is best not added?

> +
> +			if (ext->act_miss) {
> +				n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
> +								&act_index);
> +				if (!n)
> +					return TC_ACT_SHOT;
>  
> -			fchain = tcf_chain_lookup_rcu(block, ext->chain);
> +				chain = n->chain_index;
> +			}
> +
> +			fchain = tcf_chain_lookup_rcu(block, chain);
>  			if (!fchain)
>  				return TC_ACT_SHOT;
>  

...

Re: [PATCH net-next v4 1/6] net/sched: cls_api: Support hardware miss to tc action

[Paul Blakey]

On 23/01/2023 12:04, Simon Horman wrote:
> On Sun, Jan 22, 2023 at 04:55:07PM +0200, Paul Blakey wrote:
>> For drivers to support partial offload of a filter's action list,
>> add support for action miss to specify an action instance to
>> continue from in sw.
>>
>> CT action in particular can't be fully offloaded, as new connections
>> need to be handled in software. This imposes other limitations on
>> the actions that can be offloaded together with the CT action, such
>> as packet modifications.
>>
>> Assign each action on a filter's action list a unique miss_cookie
>> which drivers can then use to fill action_miss part of the tc skb
>> extension. On getting back this miss_cookie, find the action
>> instance with relevant cookie and continue classifying from there.
>>
>> Signed-off-by: Paul Blakey <paulb@nvidia.com>
>> Reviewed-by: Jiri Pirko <jiri@nvidia.com>
> 
> ...
> 
>> diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
>> index 4cabb32a2ad94..9ef85cf9b5328 100644
>> --- a/include/net/pkt_cls.h
>> +++ b/include/net/pkt_cls.h
> 
> ...
> 
>> @@ -240,21 +243,11 @@ struct tcf_exts {
>>   static inline int tcf_exts_init(struct tcf_exts *exts, struct net *net,
>>   				int action, int police)
>>   {
>> -#ifdef CONFIG_NET_CLS_ACT
>> -	exts->type = 0;
>> -	exts->nr_actions = 0;
>> -	/* Note: we do not own yet a reference on net.
>> -	 * This reference might be taken later from tcf_exts_get_net().
>> -	 */
>> -	exts->net = net;
>> -	exts->actions = kcalloc(TCA_ACT_MAX_PRIO, sizeof(struct tc_action *),
>> -				GFP_KERNEL);
>> -	if (!exts->actions)
>> -		return -ENOMEM;
>> +#ifdef CONFIG_NET_CLS
>> +	return tcf_exts_init_ex(exts, net, action, police, NULL, 0, false);
>> +#else
>> +	return -EOPNOTSUPP;
>>   #endif
> 
> nit: I think it would be nicer if there was a dummy implementation
> of tcf_exts_init_ex for the !CONFIG_NET_CLS case and #ifdefs
> could disappear from tcf_exts_init() entirely.
> 
> Likewise, elsewhere in this patch there seems to be new #if/#ifdefs
> Which may be in keeping with the style of this file. But I also
> think it's a style we ought to be moving away from.

I agree, I'll do that for v5.

> 
>> -	exts->action = action;
>> -	exts->police = police;
>> -	return 0;
>>   }
>>   
>>   /* Return false if the netns is being destroyed in cleanup_net(). Callers
> 
> ...
> 
>> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
>> index 5b4a95e8a1ee0..46524ae353c5a 100644
>> --- a/net/sched/cls_api.c
>> +++ b/net/sched/cls_api.c
> 
> ...
> 
>> +static struct tcf_exts_miss_cookie_node *
>> +tcf_exts_miss_cookie_lookup(u64 miss_cookie, int *act_index)
>> +{
>> +	union tcf_exts_miss_cookie mc = { .miss_cookie = miss_cookie, };
>> +
>> +	*act_index = mc.act_index;
>> +	return xa_load(&tcf_exts_miss_cookies_xa, mc.miss_cookie_base);
>> +}
>> +#endif /* IS_ENABLED(CONFIG_NET_TC_SKB_EXT) */
>> +
>> +static u64 tcf_exts_miss_cookie_get(u32 miss_cookie_base, int act_index)
>> +{
>> +	union tcf_exts_miss_cookie mc = { .act_index = act_index, };
>> +
>> +	if (!miss_cookie_base)
>> +		return 0;
> 
> nit: perhaps the compiler optimises this out, or it is otherwise
> unimportant,
> but doesn't the assignment
> of mc zero it's fields, other than .act_index only for:
> 
> 1. Any assignment of mc to be unused in the !miss_cookie_base case
> 2. mc.miss_cookie_base to be reassigned, otherwise
> 

It should always zero all other fields with such assignment, and both 
are equivalent while we don't have any other fields.


> FWIIW, I might have gone for something more like this (*untested*).
> 
> 	union tcf_exts_miss_cookie mc;
> 
> 	if (!miss_cookie_base)
> 		return 0;
> 
> 	mc.act_index = act_index;
> 	mc.miss_cookie_base = miss_cookie_base;
> 
> 	return mc.miss_cookie;
> 
>> +
>> +	mc.miss_cookie_base = miss_cookie_base;
>> +	return mc.miss_cookie;
>> +}
>> +
>>   #ifdef CONFIG_NET_CLS_ACT
>>   DEFINE_STATIC_KEY_FALSE(tc_skb_ext_tc);
>>   EXPORT_SYMBOL(tc_skb_ext_tc);
>> @@ -1549,6 +1642,8 @@ static inline int __tcf_classify(struct sk_buff *skb,
>>   				 const struct tcf_proto *orig_tp,
>>   				 struct tcf_result *res,
>>   				 bool compat_mode,
>> +				 struct tcf_exts_miss_cookie_node *n,
>> +				 int act_index,
>>   				 u32 *last_executed_chain)
>>   {
>>   #ifdef CONFIG_NET_CLS_ACT
>> @@ -1560,13 +1655,40 @@ static inline int __tcf_classify(struct sk_buff *skb,
>>   #endif
>>   	for (; tp; tp = rcu_dereference_bh(tp->next)) {
>>   		__be16 protocol = skb_protocol(skb, false);
>> -		int err;
>> +		int err = 0;
>>   
>> -		if (tp->protocol != protocol &&
>> -		    tp->protocol != htons(ETH_P_ALL))
>> -			continue;
>> +		if (n) {
>> +			struct tcf_exts *exts;
>>   
>> -		err = tc_classify(skb, tp, res);
>> +			if (n->tp_prio != tp->prio)
>> +				continue;
>> +
>> +			/* We re-lookup the tp and chain based on index instead
>> +			 * of having hard refs and locks to them, so do a sanity
>> +			 * check if any of tp,chain,exts was replaced by the
>> +			 * time we got here with a cookie from hardware.
>> +			 */
>> +			if (unlikely(n->tp != tp || n->tp->chain != n->chain ||
>> +				     !tp->ops->get_exts))
>> +				return TC_ACT_SHOT;
>> +
>> +			exts = tp->ops->get_exts(tp, n->handle);
> 
> I see that this is probably safe, but it's not entirely obvious
> that tp->ops->get_exts will never by NULL here >
> 1) It is invariant on n, which is set in a different function and is in turn
> 2) invariant on ext->act_miss being set, several patches away, in the driver.
> 3) Which is lastly invariant on being a code path relating to for
>     hardware offload of a classifier where tp->ops->get_exts is defined.
> 
> Or perhaps I mixed it up somehow. But I do think at a minimum this
> ought to be documented.

Yes, I check for get_exts above it, and for !exts below it.

> 
> Which brings me to a more central concern with this series: it's very
> invasive and sets up a complex relationship between the core and the
> driver. Is this the right abstraction for the problem at hand?


I think so and the changes are pretty minimal, and align with what
we currently do with sw/hw cooperation.

> 
>> +			if (unlikely(!exts || n->exts != exts))
>> +				return TC_ACT_SHOT;
>> +
>> +			n = NULL;
>> +#ifdef CONFIG_NET_CLS_ACT
>> +			err = tcf_action_exec(skb, exts->actions + act_index,
>> +					      exts->nr_actions - act_index,
>> +					      res);
>> +#endif
>> +		} else {
>> +			if (tp->protocol != protocol &&
>> +			    tp->protocol != htons(ETH_P_ALL))
>> +				continue;
>> +
>> +			err = tc_classify(skb, tp, res);
>> +		}
>>   #ifdef CONFIG_NET_CLS_ACT
>>   		if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
>>   			first_tp = orig_tp;
> 
> ...
> 
>> @@ -1606,21 +1731,33 @@ int tcf_classify(struct sk_buff *skb,
>>   #if !IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
>>   	u32 last_executed_chain = 0;
>>   
>> -	return __tcf_classify(skb, tp, tp, res, compat_mode,
>> +	return __tcf_classify(skb, tp, tp, res, compat_mode, NULL, 0,
>>   			      &last_executed_chain);
>>   #else
>>   	u32 last_executed_chain = tp ? tp->chain->index : 0;
>> +	struct tcf_exts_miss_cookie_node *n = NULL;
>>   	const struct tcf_proto *orig_tp = tp;
>>   	struct tc_skb_ext *ext;
>> +	int act_index = 0;
>>   	int ret;
>>   
>>   	if (block) {
>>   		ext = skb_ext_find(skb, TC_SKB_EXT);
>>   
>> -		if (ext && ext->chain) {
>> +		if (ext && (ext->chain || ext->act_miss)) {
>>   			struct tcf_chain *fchain;
>> +			u32 chain = ext->chain;
> 
> nit: ext->chain seems to only be used once, as it was before this patch.
> Perhaps the chain local variable is an artifact of development
> and is best not added?

It is used to share the chain lookup code below without new scope or a 
'?' op (e.g n ? n->chain_index : ext->chain) which I think is cleaner.

> 
>> +
>> +			if (ext->act_miss) {
>> +				n = tcf_exts_miss_cookie_lookup(ext->act_miss_cookie,
>> +								&act_index);
>> +				if (!n)
>> +					return TC_ACT_SHOT;
>>   
>> -			fchain = tcf_chain_lookup_rcu(block, ext->chain);
>> +				chain = n->chain_index;
>> +			}
>> +
>> +			fchain = tcf_chain_lookup_rcu(block, chain);
>>   			if (!fchain)
>>   				return TC_ACT_SHOT;
>>   
> 
> ...