[dpdk-dev] [PATCH v3 04/30] net/ena/base: generate default, random RSS hash key

[Michal Krawczyk <mk@semihalf.com>]

Although the RSS key still cannot be set, it is now being generated
every time the driver is being initialized.

Multiple devices can still have the same key if they're used by the same
driver.

Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
---
v2:
  * Remove variable declaration inside the for loop
  * Remove unlikely in condition check

v3:
  * Fixed commit logs
  * Move unrealated changes to the separate patches
  * Update the copyright date in the modified files

 drivers/net/ena/base/ena_com.c       | 34 ++++++++++++++++++++--------
 drivers/net/ena/base/ena_com.h       |  3 ++-
 drivers/net/ena/base/ena_plat_dpdk.h |  4 ++++
 drivers/net/ena/ena_ethdev.c         | 17 ++++++++++++++
 4 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ena/base/ena_com.c b/drivers/net/ena/base/ena_com.c
index 17b51b5a11..38a474b1bd 100644
--- a/drivers/net/ena/base/ena_com.c
+++ b/drivers/net/ena/base/ena_com.c
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: BSD-3-Clause
- * Copyright (c) 2015-2019 Amazon.com, Inc. or its affiliates.
+ * Copyright (c) 2015-2020 Amazon.com, Inc. or its affiliates.
  * All rights reserved.
  */
 
@@ -1032,6 +1032,19 @@ static int ena_com_get_feature(struct ena_com_dev *ena_dev,
 				      feature_ver);
 }
 
+static void ena_com_hash_key_fill_default_key(struct ena_com_dev *ena_dev)
+{
+	struct ena_admin_feature_rss_flow_hash_control *hash_key =
+		(ena_dev->rss).hash_key;
+
+	ENA_RSS_FILL_KEY(&hash_key->key, sizeof(hash_key->key));
+	/* The key is stored in the device in uint32_t array
+	 * as well as the API requires the key to be passed in this
+	 * format. Thus the size of our array should be divided by 4
+	 */
+	hash_key->keys_num = sizeof(hash_key->key) / sizeof(uint32_t);
+}
+
 static int ena_com_hash_key_allocate(struct ena_com_dev *ena_dev)
 {
 	struct ena_rss *rss = &ena_dev->rss;
@@ -2405,15 +2418,16 @@ int ena_com_fill_hash_function(struct ena_com_dev *ena_dev,
 
 	switch (func) {
 	case ENA_ADMIN_TOEPLITZ:
-		if (key_len > sizeof(hash_key->key)) {
-			ena_trc_err("key len (%hu) is bigger than the max supported (%zu)\n",
-				    key_len, sizeof(hash_key->key));
-			return ENA_COM_INVAL;
+		if (key) {
+			if (key_len != sizeof(hash_key->key)) {
+				ena_trc_err("key len (%hu) doesn't equal the supported size (%zu)\n",
+					     key_len, sizeof(hash_key->key));
+				return ENA_COM_INVAL;
+			}
+			memcpy(hash_key->key, key, key_len);
+			rss->hash_init_val = init_val;
+			hash_key->keys_num = key_len / sizeof(u32);
 		}
-
-		memcpy(hash_key->key, key, key_len);
-		rss->hash_init_val = init_val;
-		hash_key->keys_num = key_len >> 2;
 		break;
 	case ENA_ADMIN_CRC32:
 		rss->hash_init_val = init_val;
@@ -2738,6 +2752,8 @@ int ena_com_rss_init(struct ena_com_dev *ena_dev, u16 indr_tbl_log_size)
 	if (unlikely(rc))
 		goto err_hash_key;
 
+	ena_com_hash_key_fill_default_key(ena_dev);
+
 	rc = ena_com_hash_ctrl_init(ena_dev);
 	if (unlikely(rc))
 		goto err_hash_ctrl;
diff --git a/drivers/net/ena/base/ena_com.h b/drivers/net/ena/base/ena_com.h
index f2ef26c91b..d58c802edf 100644
--- a/drivers/net/ena/base/ena_com.h
+++ b/drivers/net/ena/base/ena_com.h
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: BSD-3-Clause
- * Copyright (c) 2015-2019 Amazon.com, Inc. or its affiliates.
+ * Copyright (c) 2015-2020 Amazon.com, Inc. or its affiliates.
  * All rights reserved.
  */
 
@@ -53,6 +53,7 @@
 #define ENA_INTR_DELAY_NEW_VALUE_WEIGHT			4
 #define ENA_INTR_MODER_LEVEL_STRIDE			1
 #define ENA_INTR_BYTE_COUNT_NOT_SUPPORTED		0xFFFFFF
+#define ENA_HASH_KEY_SIZE				40
 
 #define ENA_HW_HINTS_NO_TIMEOUT				0xFFFF
 
diff --git a/drivers/net/ena/base/ena_plat_dpdk.h b/drivers/net/ena/base/ena_plat_dpdk.h
index 4b8fe017dd..e9b33bc36c 100644
--- a/drivers/net/ena/base/ena_plat_dpdk.h
+++ b/drivers/net/ena/base/ena_plat_dpdk.h
@@ -301,6 +301,10 @@ extern rte_atomic32_t ena_alloc_cnt;
 
 #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
 
+void ena_rss_key_fill(void *key, size_t size);
+
+#define ENA_RSS_FILL_KEY(key, size) ena_rss_key_fill(key, size)
+
 #include "ena_includes.h"
 
 #endif /* DPDK_ENA_COM_ENA_PLAT_DPDK_H_ */
diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
index e0ed28419c..f1202d99f2 100644
--- a/drivers/net/ena/ena_ethdev.c
+++ b/drivers/net/ena/ena_ethdev.c
@@ -256,6 +256,23 @@ static const struct eth_dev_ops ena_dev_ops = {
 	.reta_query           = ena_rss_reta_query,
 };
 
+void ena_rss_key_fill(void *key, size_t size)
+{
+	static bool key_generated;
+	static uint8_t default_key[ENA_HASH_KEY_SIZE];
+	size_t i;
+
+	RTE_ASSERT(size <= ENA_HASH_KEY_SIZE);
+
+	if (!key_generated) {
+		for (i = 0; i < ENA_HASH_KEY_SIZE; ++i)
+			default_key[i] = rte_rand() & 0xff;
+		key_generated = true;
+	}
+
+	rte_memcpy(key, default_key, size);
+}
+
 static inline void ena_rx_mbuf_prepare(struct rte_mbuf *mbuf,
 				       struct ena_com_rx_ctx *ena_rx_ctx)
 {
-- 
2.20.1