[PATCH v4 1/3] ethdev: add flow rule group description

[Rongwei Liu]

Add more sentences to describe the group concepts
and define group 0 as root group for traffic to search a
hit rule.

Signed-off-by: Rongwei Liu <rongweil at nvidia.com>
---
 lib/ethdev/rte_flow.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
index b60987db4b..e71ac0c199 100644
--- a/lib/ethdev/rte_flow.h
+++ b/lib/ethdev/rte_flow.h
@@ -86,7 +86,18 @@ extern "C" {
  * but may be valid in a few cases.
  */
 struct rte_flow_attr {
-	uint32_t group; /**< Priority group. */
+	/**
+	 * A group is a superset of multiple rules.
+	 * The default group is 0 and is processed for all packets.
+	 * The group 0 of bifurcated drivers is shared with the kernel.
+	 * Rules in other groups are processed only if the group is chained
+	 * by a jump action from a previously matched rule.
+	 * It means the group hierarchy is made by the flow rules,
+	 * and the group 0 is the hierarchy root.
+	 * Note there is no automatic dead loop protection.
+	 * @see rte_flow_action_jump
+	 */
+	uint32_t group;
 	uint32_t priority; /**< Rule priority level within group. */
 	/**
 	 * The rule in question applies to ingress traffic (non-"transfer").
-- 
2.27.0