[dpdk-stable] patch 'eventdev/eth_rx: fix WRR buffer overrun' has been queued to stable release 20.11.4

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 20.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/12/21. 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/steevenlee/dpdk

This queued commit can be viewed at:
https://github.com/steevenlee/dpdk/commit/1d47c1198e1c7b982e5b5f13775bf1d628a5bfd1

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 1d47c1198e1c7b982e5b5f13775bf1d628a5bfd1 Mon Sep 17 00:00:00 2001
From: Naga Harish K S V <s.v.naga.harish.k at intel.com>
Date: Mon, 18 Oct 2021 03:25:41 -0500
Subject: [PATCH] eventdev/eth_rx: fix WRR buffer overrun
Cc: Xueming Li <xuemingl at nvidia.com>

[ upstream commit 81da8a5ff440eda60635c849c9e9b3d253838da9 ]

When a poll queue is removed from a rx_adapter instance, the WRR poll
array is recomputed. The wrr array length is reduced in this case. The
next wrr position to poll is stored in wrr_pos variable of rx_adapter
instance. This wrr_pos can become invalid in some cases after wrr is
recomputed. Using this variable to get the next queue and device pair
may leed to wrr buffer overruns.

Resetting the wrr_pos to zero after recomputation of wrr array fixes
the buffer overrun issue.

Fixes: 9c38b704d280 ("eventdev: add eth Rx adapter implementation")

Signed-off-by: Naga Harish K S V <s.v.naga.harish.k at intel.com>
Acked-by: Jay Jayatheerthan <jay.jayatheerthan at intel.com>
---
 lib/librte_eventdev/rte_event_eth_rx_adapter.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/librte_eventdev/rte_event_eth_rx_adapter.c b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
index 663b446c05..89213297db 100644
--- a/lib/librte_eventdev/rte_event_eth_rx_adapter.c
+++ b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
@@ -2239,6 +2239,11 @@ rte_event_eth_rx_adapter_queue_del(uint8_t id, uint16_t eth_dev_id,
 		rx_adapter->eth_rx_poll = rx_poll;
 		rx_adapter->wrr_sched = rx_wrr;
 		rx_adapter->wrr_len = nb_wrr;
+		/*
+		 * reset next poll start position (wrr_pos) to avoid buffer
+		 * overrun when wrr_len is reduced in case of queue delete
+		 */
+		rx_adapter->wrr_pos = 0;
 		rx_adapter->num_intr_vec += num_intr_vec;
 
 		if (dev_info->nb_dev_queues == 0) {
-- 
2.33.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-11-10 14:17:09.533836359 +0800
+++ 0171-eventdev-eth_rx-fix-WRR-buffer-overrun.patch	2021-11-10 14:17:01.984078497 +0800
@@ -1 +1 @@
-From 81da8a5ff440eda60635c849c9e9b3d253838da9 Mon Sep 17 00:00:00 2001
+From 1d47c1198e1c7b982e5b5f13775bf1d628a5bfd1 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit 81da8a5ff440eda60635c849c9e9b3d253838da9 ]
@@ -17 +19,0 @@
-Cc: stable at dpdk.org
@@ -22 +24 @@
- lib/eventdev/rte_event_eth_rx_adapter.c | 5 +++++
+ lib/librte_eventdev/rte_event_eth_rx_adapter.c | 5 +++++
@@ -25,5 +27,5 @@
-diff --git a/lib/eventdev/rte_event_eth_rx_adapter.c b/lib/eventdev/rte_event_eth_rx_adapter.c
-index e570f2f085..f07dd4d822 100644
---- a/lib/eventdev/rte_event_eth_rx_adapter.c
-+++ b/lib/eventdev/rte_event_eth_rx_adapter.c
-@@ -2739,6 +2739,11 @@ rte_event_eth_rx_adapter_queue_del(uint8_t id, uint16_t eth_dev_id,
+diff --git a/lib/librte_eventdev/rte_event_eth_rx_adapter.c b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
+index 663b446c05..89213297db 100644
+--- a/lib/librte_eventdev/rte_event_eth_rx_adapter.c
++++ b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
+@@ -2239,6 +2239,11 @@ rte_event_eth_rx_adapter_queue_del(uint8_t id, uint16_t eth_dev_id,