[dpdk-stable] patch 'net/mlx5: fix RSS RETA reset on start' has been queued to stable release 19.11.6

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.6

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 10/30/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Luca Boccassi

---
>From ae09dbd15a26d99f607627bb3e0595efefcb642c Mon Sep 17 00:00:00 2001
From: Maxime Leroy <maxime.leroy at 6wind.com>
Date: Thu, 16 Jul 2020 12:43:20 +0200
Subject: [PATCH] net/mlx5: fix RSS RETA reset on start

[ upstream commit e0d449513bcab58d9ab40bfeeb113b0db3093cad ]

The following sequences was working fine on mlx5:
   rte_eth_dev_configure(portid, ...);

   for (queueid = 0; queueid < nb_txq; queueid++)
      rte_eth_tx_queue_setup(portid, queueid, ...);

   for (queueid = 0; queueid < nb_rxq; queueid++)
      rte_eth_rx_queue_setup(portid, queueid, ...);

  // use a custom reta configuration
  rte_eth_dev_rss_reta_update(portid, reta_conf, reta_size);
  rte_eth_dev_start(portid);

We were able to configure a custom reta before starting the port.

The commit "net/mlx5: support RSS on hairpin" breaks this logic by
moving the code initializing the RSS reta from rte_eth_dev_configure
into rte_eth_dev_start.

To fix the issue, the skip_default_rss_reta is always set to 1 in
rte_eth_dev_rss_reta to avoid reconfigure the rss reta when the device
is started.

Fixes: 63bd16292c3a ("net/mlx5: support RSS on hairpin")

Signed-off-by: Maxime Leroy <maxime.leroy at 6wind.com>
Acked-by: Ori Kam <orika at nvidia.com>
---
 drivers/net/mlx5/mlx5_rss.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_rss.c b/drivers/net/mlx5/mlx5_rss.c
index 102826452d..170005a7af 100644
--- a/drivers/net/mlx5/mlx5_rss.c
+++ b/drivers/net/mlx5/mlx5_rss.c
@@ -221,9 +221,11 @@ mlx5_dev_rss_reta_update(struct rte_eth_dev *dev,
 		assert(reta_conf[idx].reta[pos] < priv->rxqs_n);
 		(*priv->reta_idx)[i] = reta_conf[idx].reta[pos];
 	}
+
+	priv->skip_default_rss_reta = 1;
+
 	if (dev->data->dev_started) {
 		mlx5_dev_stop(dev);
-		priv->skip_default_rss_reta = 1;
 		return mlx5_dev_start(dev);
 	}
 	return 0;
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-10-28 10:35:12.912757146 +0000
+++ 0036-net-mlx5-fix-RSS-RETA-reset-on-start.patch	2020-10-28 10:35:11.480829671 +0000
@@ -1,8 +1,10 @@
-From e0d449513bcab58d9ab40bfeeb113b0db3093cad Mon Sep 17 00:00:00 2001
+From ae09dbd15a26d99f607627bb3e0595efefcb642c Mon Sep 17 00:00:00 2001
 From: Maxime Leroy <maxime.leroy at 6wind.com>
 Date: Thu, 16 Jul 2020 12:43:20 +0200
 Subject: [PATCH] net/mlx5: fix RSS RETA reset on start
 
+[ upstream commit e0d449513bcab58d9ab40bfeeb113b0db3093cad ]
+
 The following sequences was working fine on mlx5:
    rte_eth_dev_configure(portid, ...);
 
@@ -27,7 +29,6 @@
 is started.
 
 Fixes: 63bd16292c3a ("net/mlx5: support RSS on hairpin")
-Cc: stable at dpdk.org
 
 Signed-off-by: Maxime Leroy <maxime.leroy at 6wind.com>
 Acked-by: Ori Kam <orika at nvidia.com>
@@ -36,11 +37,11 @@
  1 file changed, 3 insertions(+), 1 deletion(-)
 
 diff --git a/drivers/net/mlx5/mlx5_rss.c b/drivers/net/mlx5/mlx5_rss.c
-index a63cc8df9a..845cebe2e8 100644
+index 102826452d..170005a7af 100644
 --- a/drivers/net/mlx5/mlx5_rss.c
 +++ b/drivers/net/mlx5/mlx5_rss.c
-@@ -215,9 +215,11 @@ mlx5_dev_rss_reta_update(struct rte_eth_dev *dev,
- 		MLX5_ASSERT(reta_conf[idx].reta[pos] < priv->rxqs_n);
+@@ -221,9 +221,11 @@ mlx5_dev_rss_reta_update(struct rte_eth_dev *dev,
+ 		assert(reta_conf[idx].reta[pos] < priv->rxqs_n);
  		(*priv->reta_idx)[i] = reta_conf[idx].reta[pos];
  	}
 +