[dpdk-stable] patch 'vdpa/mlx5: fix configuration mutex cleanup' has been queued to stable release 20.11.1

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 02/07/21. 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/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/9bf462abbe3a3e688c8d97bc836d21f6ad4b7f70

Thanks.

Luca Boccassi

---
>From 9bf462abbe3a3e688c8d97bc836d21f6ad4b7f70 Mon Sep 17 00:00:00 2001
From: Matan Azrad <matan at nvidia.com>
Date: Wed, 6 Jan 2021 06:43:29 +0000
Subject: [PATCH] vdpa/mlx5: fix configuration mutex cleanup

[ upstream commit f00e5a15af5a0c5df1a7390364b6454d34586335 ]

When the vDPA device is closed, the driver polling thread is canceled.
The polling thread locks the configuration mutex while it polls the CQs.

When the cancellation happens, it may terminate the thread inside the
critical section what remains the configuration mutex locked.

After device close, the driver may be configured again, in this case,
for example, when the first queue state is updated, the driver tries to
lock the mutex again and deadlock appears.

Initialize the mutex after the polling thread cancellation.

Fixes: 99abbd62c272 ("vdpa/mlx5: fix queue update synchronization")

Signed-off-by: Matan Azrad <matan at nvidia.com>
Acked-by: Xueming Li <xuemingl at nvidia.com>
Acked-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.c b/drivers/vdpa/mlx5/mlx5_vdpa.c
index b64f364eb7..0b2f1ab68e 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
@@ -295,6 +295,8 @@ mlx5_vdpa_dev_close(int vid)
 	}
 	priv->configured = 0;
 	priv->vid = 0;
+	/* The mutex may stay locked after event thread cancel - initiate it. */
+	pthread_mutex_init(&priv->vq_config_lock, NULL);
 	DRV_LOG(INFO, "vDPA device %d was closed.", vid);
 	return ret;
 }
-- 
2.29.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-02-05 11:18:40.197745984 +0000
+++ 0250-vdpa-mlx5-fix-configuration-mutex-cleanup.patch	2021-02-05 11:18:29.262699793 +0000
@@ -1 +1 @@
-From f00e5a15af5a0c5df1a7390364b6454d34586335 Mon Sep 17 00:00:00 2001
+From 9bf462abbe3a3e688c8d97bc836d21f6ad4b7f70 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit f00e5a15af5a0c5df1a7390364b6454d34586335 ]
+
@@ -19 +20,0 @@
-Cc: stable at dpdk.org
@@ -29 +30 @@
-index 0f22a863a3..4c2d886bd7 100644
+index b64f364eb7..0b2f1ab68e 100644