[PATCH v2 1/5] ethdev: support setting and querying rss algorithm

[Jie Hai]

Currently, rte_eth_rss_conf supports configuring and querying
rss hash functions, rss key and it's length, but not rss hash
algorithm.

The structure ``rte_eth_rss_conf`` is extended by adding a new
field "func". This represents the RSS algorithms to apply. The
following API is affected:
	- rte_eth_dev_configure
	- rte_eth_dev_rss_hash_update
	- rte_eth_dev_rss_hash_conf_get

If the value of "func" used for configuration is a gibberish
value, report the error and return. Do the same for
rte_eth_dev_rss_hash_update and rte_eth_dev_configure.

To check whether the drivers report the "func" field, it is set
to default value before querying.

Signed-off-by: Jie Hai <haijie1 at huawei.com>
Signed-off-by: Dongdong Liu <liudongdong3 at huawei.com>
---
 doc/guides/rel_notes/release_23_11.rst |  2 ++
 lib/ethdev/rte_ethdev.c                | 17 +++++++++++++++++
 lib/ethdev/rte_ethdev.h                |  6 ++++++
 3 files changed, 25 insertions(+)

diff --git a/doc/guides/rel_notes/release_23_11.rst b/doc/guides/rel_notes/release_23_11.rst
index 4411bb32c195..3746436e8bc9 100644
--- a/doc/guides/rel_notes/release_23_11.rst
+++ b/doc/guides/rel_notes/release_23_11.rst
@@ -123,6 +123,8 @@ ABI Changes
    Also, make sure to start the actual text at the margin.
    =======================================================
 
+   * ethdev: Added "func" field to ``rte_eth_rss_conf`` structure for RSS hash
+     algorithm.
 
 Known Issues
 ------------
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 0840d2b5942a..4cbcdb344cac 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -1445,6 +1445,14 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		goto rollback;
 	}
 
+	if (dev_conf->rx_adv_conf.rss_conf.func >= RTE_ETH_HASH_FUNCTION_MAX) {
+		RTE_ETHDEV_LOG(ERR,
+			"Ethdev port_id=%u invalid rss hash function (%u)\n",
+			port_id, dev_conf->rx_adv_conf.rss_conf.func);
+		ret = -EINVAL;
+		goto rollback;
+	}
+
 	/* Check if Rx RSS distribution is disabled but RSS hash is enabled. */
 	if (((dev_conf->rxmode.mq_mode & RTE_ETH_MQ_RX_RSS_FLAG) == 0) &&
 	    (dev_conf->rxmode.offloads & RTE_ETH_RX_OFFLOAD_RSS_HASH)) {
@@ -4630,6 +4638,13 @@ rte_eth_dev_rss_hash_update(uint16_t port_id,
 		return -ENOTSUP;
 	}
 
+	if (rss_conf->func >= RTE_ETH_HASH_FUNCTION_MAX) {
+		RTE_ETHDEV_LOG(ERR,
+			"Ethdev port_id=%u invalid rss hash function (%u)\n",
+			port_id, rss_conf->func);
+		return -EINVAL;
+	}
+
 	if (*dev->dev_ops->rss_hash_update == NULL)
 		return -ENOTSUP;
 	ret = eth_err(port_id, (*dev->dev_ops->rss_hash_update)(dev,
@@ -4657,6 +4672,8 @@ rte_eth_dev_rss_hash_conf_get(uint16_t port_id,
 		return -EINVAL;
 	}
 
+	rss_conf->func = RTE_ETH_HASH_FUNCTION_DEFAULT;
+
 	if (*dev->dev_ops->rss_hash_conf_get == NULL)
 		return -ENOTSUP;
 	ret = eth_err(port_id, (*dev->dev_ops->rss_hash_conf_get)(dev,
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 04a2564f222a..1bb5f23059ca 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -174,6 +174,7 @@ extern "C" {
 
 #include "rte_ethdev_trace_fp.h"
 #include "rte_dev_info.h"
+#include "rte_flow.h"
 
 extern int rte_eth_dev_logtype;
 
@@ -461,11 +462,16 @@ struct rte_vlan_filter_conf {
  * The *rss_hf* field of the *rss_conf* structure indicates the different
  * types of IPv4/IPv6 packets to which the RSS hashing must be applied.
  * Supplying an *rss_hf* equal to zero disables the RSS feature.
+ *
+ * The *func* field of the *rss_conf* structure indicates the hash algorithm
+ * applied by the RSS hashing. Passing RTE_ETH_HASH_FUNCTION_DEFAULT allows
+ * the PMD to use its best-effort algorithm rather than a specific one.
  */
 struct rte_eth_rss_conf {
 	uint8_t *rss_key;    /**< If not NULL, 40-byte hash key. */
 	uint8_t rss_key_len; /**< hash key length in bytes. */
 	uint64_t rss_hf;     /**< Hash functions to apply - see below. */
+	enum rte_eth_hash_function func;	/**< Hash algorithm to apply. */
 };
 
 /*
-- 
2.33.0