[PATCH 4.9 12/88] net: ena: fix incorrect default RSS key

[Greg Kroah-Hartman]

From: Arthur Kiyanovski <akiyano@xxxxxxxxxx>

[ Upstream commit 0d1c3de7b8c78a5e44b74b62ede4a63629f5d811 ]

Bug description:
When running "ethtool -x <if_name>" the key shows up as all zeros.

When we use "ethtool -X <if_name> hfunc toeplitz hkey <some:random:key>" to
set the key and then try to retrieve it using "ethtool -x <if_name>" then
we return the correct key because we return the one we saved.

Bug cause:
We don't fetch the key from the device but instead return the key
that we have saved internally which is by default set to zero upon
allocation.

Fix:
This commit fixes the issue by initializing the key to a random value
using netdev_rss_key_fill().

Fixes: 1738cd3ed342 ("net: ena: Add a driver for Amazon Elastic Network Adapters (ENA)")
Signed-off-by: Sameeh Jubran <sameehj@xxxxxxxxxx>
Signed-off-by: Arthur Kiyanovski <akiyano@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/amazon/ena/ena_com.c | 15 +++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_com.h |  1 +
 2 files changed, 16 insertions(+)

diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
index f09b7887039a2..be8a2d48c98f2 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -839,6 +839,19 @@ static int ena_com_get_feature(struct ena_com_dev *ena_dev,
 				      0);
 }
 
+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;
+
+	netdev_rss_key_fill(&hash_key->key, sizeof(hash_key->key));
+	/* The key is stored in the device in u32 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(u32);
+}
+
 static int ena_com_hash_key_allocate(struct ena_com_dev *ena_dev)
 {
 	struct ena_rss *rss = &ena_dev->rss;
@@ -2367,6 +2380,8 @@ 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/ethernet/amazon/ena/ena_com.h b/drivers/net/ethernet/amazon/ena/ena_com.h
index 509d7b8e15ab9..628bf7a8fc0cb 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.h
+++ b/drivers/net/ethernet/amazon/ena/ena_com.h
@@ -41,6 +41,7 @@
 #include <linux/spinlock.h>
 #include <linux/types.h>
 #include <linux/wait.h>
+#include <linux/netdevice.h>
 
 #include "ena_common_defs.h"
 #include "ena_admin_defs.h"
-- 
2.20.1