patch 'net/ixgbevf: fix RSS init for x550 NICs' has been queued to stable release 21.11.7

[Kevin Traynor <ktraynor@redhat.com>]

Hi,

FYI, your patch has been queued to stable release 21.11.7

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 03/13/24. 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.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/153ce28fcff59b6cf80b94c45811244cdb847f7e

Thanks.

Kevin

---
From 153ce28fcff59b6cf80b94c45811244cdb847f7e Mon Sep 17 00:00:00 2001
From: Edwin Brossette <edwin.brossette@6wind.com>
Date: Thu, 15 Feb 2024 14:31:45 +0100
Subject: [PATCH] net/ixgbevf: fix RSS init for x550 NICs

[ upstream commit 3a53577d5f390e8635a672b79616e54c59b330ab ]

Different Intel NICs with the igxbe PMD do not handle RSS in the same
way when working with virtualization. While some NICs like Intel 82599ES
only have a single RSS table in the device and leave all RSS features to
be handled by the PF, some other NICs like x550 let the VF handle RSS
features. This can lead to different behavior when RSS is enabled
depending on the model of nic used.

In particular, ixgbevf_dev_rx_init() does not configure RSS parameters
at device init, even if the multi-queue mode option is set in the device
configuration (ie. RTE_ETH_MQ_RX_RSS is set). Note that this issue went
unnoticed until now, probably because some NICs do not really have
support for RSS in virtualization mode.

Thus, depending on the NIC used, we can we find ourselves in a situation
where RSS is not configured despite being enabled. This will cause
serious performance issues because the RSS RETA table will be fully
zeroed, causing all packets to go only to the first queue, leaving all
other queues empty.

By looking at ixgbe_reta_size_get(), we can see that only X550 NIC
models have a non zero RETA size set in VF mode. Therefore, add a call
to ixgbe_rss_configure() for these cards in ixgbevf_dev_rx_init() if the
option to enable RSS is set.

Fixes: f4d1598ee14f ("ixgbevf: support RSS config on x550")

Signed-off-by: Edwin Brossette <edwin.brossette@6wind.com>
Acked-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
---
 drivers/net/ixgbe/ixgbe_rxtx.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index c137707869..e3c611a40f 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -5742,4 +5742,23 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
 	IXGBE_WRITE_REG(hw, IXGBE_VFPSRTYPE, psrtype);
 
+	/* Initialize the rss for x550_vf cards if enabled */
+	switch (hw->mac.type) {
+	case ixgbe_mac_X550_vf:
+	case ixgbe_mac_X550EM_x_vf:
+	case ixgbe_mac_X550EM_a_vf:
+		switch (dev->data->dev_conf.rxmode.mq_mode) {
+		case RTE_ETH_MQ_RX_RSS:
+		case RTE_ETH_MQ_RX_DCB_RSS:
+		case RTE_ETH_MQ_RX_VMDQ_RSS:
+			ixgbe_rss_configure(dev);
+			break;
+		default:
+			break;
+		}
+		break;
+	default:
+		break;
+	}
+
 	ixgbe_set_rx_function(dev);
 
-- 
2.43.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2024-03-08 13:47:49.407409035 +0000
+++ 0012-net-ixgbevf-fix-RSS-init-for-x550-NICs.patch	2024-03-08 13:47:49.003686619 +0000
@@ -1 +1 @@
-From 3a53577d5f390e8635a672b79616e54c59b330ab Mon Sep 17 00:00:00 2001
+From 153ce28fcff59b6cf80b94c45811244cdb847f7e Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 3a53577d5f390e8635a672b79616e54c59b330ab ]
+
@@ -31 +32,0 @@
-Cc: stable@dpdk.org
@@ -40 +41 @@
-index 90b0a7004f..f6c17d4efb 100644
+index c137707869..e3c611a40f 100644
@@ -43 +44 @@
-@@ -5845,4 +5845,23 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
+@@ -5742,4 +5742,23 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)