[dpdk-stable] patch 'net/virtio-user: do not reset owner when driver resets' has been queued to stable release 18.08.1

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 18.08.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/29/18. 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. If the code is different (ie: not only metadata diffs), due for example to
a change in context or macro names, please double check it.

Thanks.

Kevin Traynor

---
>From e08b77f3ffdbcfad32bbbe69c6f2c998ee700c69 Mon Sep 17 00:00:00 2001
From: Tiwei Bie <tiwei.bie at intel.com>
Date: Mon, 29 Oct 2018 13:28:05 +0800
Subject: [PATCH] net/virtio-user: do not reset owner when driver resets

[ upstream commit 74dc6746a0f195907ec487df7de18a856108482f ]

When driver resets the device, virtio-user just needs to send
GET_VRING_BASE messages to stop the vhost backend, and that's
what QEMU does. With this change, we won't need to set owner
when starting virtio-user device anymore. This will help us to
get rid of below error message on startup:

vhost_kernel_ioctl(): VHOST_SET_OWNER failed: Device or resource busy

Fixes: bce7e9050f9b ("net/virtio-user: fix start with kernel vhost")
Fixes: 0d6a8752ac9d ("net/virtio-user: fix crash as features change")

Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 .../net/virtio/virtio_user/virtio_user_dev.c  | 22 ++++++++++++-------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index bef253488..85c35246b 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -135,7 +135,4 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 		goto error;
 
-	/* Do not check return as already done in init, or reset in stop */
-	dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL);
-
 	/* Step 0: tell vhost to create queues */
 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
@@ -182,5 +179,7 @@ error:
 int virtio_user_stop_device(struct virtio_user_dev *dev)
 {
+	struct vhost_vring_state state;
 	uint32_t i;
+	int error = 0;
 
 	pthread_mutex_lock(&dev->mutex);
@@ -191,14 +190,21 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 		dev->ops->enable_qp(dev, i, 0);
 
-	if (dev->ops->send_request(dev, VHOST_USER_RESET_OWNER, NULL) < 0) {
-		PMD_DRV_LOG(INFO, "Failed to reset the device\n");
-		pthread_mutex_unlock(&dev->mutex);
-		return -1;
+	/* Stop the backend. */
+	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
+		state.index = i;
+		if (dev->ops->send_request(dev, VHOST_USER_GET_VRING_BASE,
+					   &state) < 0) {
+			PMD_DRV_LOG(ERR, "get_vring_base failed, index=%u\n",
+				    i);
+			error = -1;
+			goto out;
+		}
 	}
+
 	dev->started = false;
 out:
 	pthread_mutex_unlock(&dev->mutex);
 
-	return 0;
+	return error;
 }
 
-- 
2.19.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2018-11-23 10:22:55.113234621 +0000
+++ 0033-net-virtio-user-do-not-reset-owner-when-driver-reset.patch	2018-11-23 10:22:54.000000000 +0000
@@ -1,8 +1,10 @@
-From 74dc6746a0f195907ec487df7de18a856108482f Mon Sep 17 00:00:00 2001
+From e08b77f3ffdbcfad32bbbe69c6f2c998ee700c69 Mon Sep 17 00:00:00 2001
 From: Tiwei Bie <tiwei.bie at intel.com>
 Date: Mon, 29 Oct 2018 13:28:05 +0800
 Subject: [PATCH] net/virtio-user: do not reset owner when driver resets
 
+[ upstream commit 74dc6746a0f195907ec487df7de18a856108482f ]
+
 When driver resets the device, virtio-user just needs to send
 GET_VRING_BASE messages to stop the vhost backend, and that's
 what QEMU does. With this change, we won't need to set owner
@@ -13,7 +15,6 @@
 
 Fixes: bce7e9050f9b ("net/virtio-user: fix start with kernel vhost")
 Fixes: 0d6a8752ac9d ("net/virtio-user: fix crash as features change")
-Cc: stable at dpdk.org
 
 Signed-off-by: Tiwei Bie <tiwei.bie at intel.com>
 Reviewed-by: Maxime Coquelin <maxime.coquelin at redhat.com>
@@ -22,7 +23,7 @@
  1 file changed, 14 insertions(+), 8 deletions(-)
 
 diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
-index 0e3563051..0eb0f244b 100644
+index bef253488..85c35246b 100644
 --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
 +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
 @@ -135,7 +135,4 @@ virtio_user_start_device(struct virtio_user_dev *dev)