[PATCH 06/15] net/enic: enable limited RSS flow action

[Hyong Youb Kim <hyonkim@cisco.com>]

Some apps like OVS-DPDK use MARK+RSS flow rules in order to offload
packet matching to the NIC. The RSS action in such flow rules simply
indicates "receive packet normally", not trying to override the port
wide RSS. The action is included in the flow rules simply to terminate
them, as MARK is not a fate-deciding action. And, the RSS action has a
most basic config: default hash, level, types, null key, and identity
queue mapping.

Recent VIC adapters can support these "mark and receive" flow
rules. So, enable support for RSS action for this limited use case.

Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>
Reviewed-by: John Daley <johndale@cisco.com>
---
 drivers/net/enic/enic_flow.c | 48 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/drivers/net/enic/enic_flow.c b/drivers/net/enic/enic_flow.c
index c60476c8c..0f6b6b930 100644
--- a/drivers/net/enic/enic_flow.c
+++ b/drivers/net/enic/enic_flow.c
@@ -45,7 +45,8 @@ struct enic_filter_cap {
 };
 
 /* functions for copying flow actions into enic actions */
-typedef int (copy_action_fn)(const struct rte_flow_action actions[],
+typedef int (copy_action_fn)(struct enic *enic,
+			     const struct rte_flow_action actions[],
 			     struct filter_action_v2 *enic_action);
 
 /* functions for copying items into enic filters */
@@ -57,8 +58,7 @@ struct enic_action_cap {
 	/** list of valid actions */
 	const enum rte_flow_action_type *actions;
 	/** copy function for a particular NIC */
-	int (*copy_fn)(const struct rte_flow_action actions[],
-		       struct filter_action_v2 *enic_action);
+	copy_action_fn *copy_fn;
 };
 
 /* Forward declarations */
@@ -282,6 +282,7 @@ static const enum rte_flow_action_type enic_supported_actions_v2_id[] = {
 	RTE_FLOW_ACTION_TYPE_QUEUE,
 	RTE_FLOW_ACTION_TYPE_MARK,
 	RTE_FLOW_ACTION_TYPE_FLAG,
+	RTE_FLOW_ACTION_TYPE_RSS,
 	RTE_FLOW_ACTION_TYPE_END,
 };
 
@@ -290,6 +291,7 @@ static const enum rte_flow_action_type enic_supported_actions_v2_drop[] = {
 	RTE_FLOW_ACTION_TYPE_MARK,
 	RTE_FLOW_ACTION_TYPE_FLAG,
 	RTE_FLOW_ACTION_TYPE_DROP,
+	RTE_FLOW_ACTION_TYPE_RSS,
 	RTE_FLOW_ACTION_TYPE_END,
 };
 
@@ -299,6 +301,7 @@ static const enum rte_flow_action_type enic_supported_actions_v2_count[] = {
 	RTE_FLOW_ACTION_TYPE_FLAG,
 	RTE_FLOW_ACTION_TYPE_DROP,
 	RTE_FLOW_ACTION_TYPE_COUNT,
+	RTE_FLOW_ACTION_TYPE_RSS,
 	RTE_FLOW_ACTION_TYPE_END,
 };
 
@@ -1016,7 +1019,8 @@ enic_copy_filter(const struct rte_flow_item pattern[],
  * @param error[out]
  */
 static int
-enic_copy_action_v1(const struct rte_flow_action actions[],
+enic_copy_action_v1(__rte_unused struct enic *enic,
+		    const struct rte_flow_action actions[],
 		    struct filter_action_v2 *enic_action)
 {
 	enum { FATE = 1, };
@@ -1062,7 +1066,8 @@ enic_copy_action_v1(const struct rte_flow_action actions[],
  * @param error[out]
  */
 static int
-enic_copy_action_v2(const struct rte_flow_action actions[],
+enic_copy_action_v2(struct enic *enic,
+		    const struct rte_flow_action actions[],
 		    struct filter_action_v2 *enic_action)
 {
 	enum { FATE = 1, MARK = 2, };
@@ -1128,6 +1133,37 @@ enic_copy_action_v2(const struct rte_flow_action actions[],
 			enic_action->flags |= FILTER_ACTION_COUNTER_FLAG;
 			break;
 		}
+		case RTE_FLOW_ACTION_TYPE_RSS: {
+			const struct rte_flow_action_rss *rss =
+				(const struct rte_flow_action_rss *)
+				actions->conf;
+			bool allow;
+			uint16_t i;
+
+			/*
+			 * Hardware does not support general RSS actions, but
+			 * we can still support the dummy one that is used to
+			 * "receive normally".
+			 */
+			allow = rss->func == RTE_ETH_HASH_FUNCTION_DEFAULT &&
+				rss->level == 0 &&
+				(rss->types == 0 ||
+				 rss->types == enic->rss_hf) &&
+				rss->queue_num == enic->rq_count &&
+				rss->key_len == 0;
+			/* Identity queue map is ok */
+			for (i = 0; i < rss->queue_num; i++)
+				allow = allow && (i == rss->queue[i]);
+			if (!allow)
+				return ENOTSUP;
+			if (overlap & FATE)
+				return ENOTSUP;
+			/* Need MARK or FLAG */
+			if (!(overlap & MARK))
+				return ENOTSUP;
+			overlap |= FATE;
+			break;
+		}
 		case RTE_FLOW_ACTION_TYPE_VOID:
 			continue;
 		default:
@@ -1418,7 +1454,7 @@ enic_flow_parse(struct rte_eth_dev *dev,
 				   action, "Invalid action.");
 		return -rte_errno;
 	}
-	ret = enic_action_cap->copy_fn(actions, enic_action);
+	ret = enic_action_cap->copy_fn(enic, actions, enic_action);
 	if (ret) {
 		rte_flow_error_set(error, ENOTSUP, RTE_FLOW_ERROR_TYPE_HANDLE,
 			   NULL, "Unsupported action.");
-- 
2.16.2