[dpdk-stable] patch 'net/virtio-user: do not reset owner when driver resets' has been queued to LTS release 16.11.9

[Luca Boccassi]

Hi,

FYI, your patch has been queued to LTS release 16.11.9

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/10/18. 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.

Luca Boccassi

---
>From 4af6a676730e9fbebf916c17fce4bb41f7e52250 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>
---
 drivers/net/virtio/virtio_user/virtio_user_dev.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 8bb155d8c..3e6787a04 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -142,9 +142,6 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	uint64_t features;
 	int ret;
 
-	/* Do not check return as already done in init, or reset in stop */
-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_OWNER, NULL);
-
 	/* Step 0: tell vhost to create queues */
 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
 		goto error;
@@ -185,6 +182,7 @@ error:
 
 int virtio_user_stop_device(struct virtio_user_dev *dev)
 {
+	struct vhost_vring_state state;
 	uint32_t i;
 
 	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
@@ -195,6 +193,17 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
 	for (i = 0; i < dev->max_queue_pairs; ++i)
 		vhost_user_enable_queue_pair(dev->vhostfd, i, 0);
 
+	/* Stop the backend. */
+	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
+		state.index = i;
+		if (vhost_user_sock(dev->vhostfd, VHOST_USER_GET_VRING_BASE,
+					   &state) < 0) {
+			PMD_DRV_LOG(ERR, "get_vring_base failed, index=%u\n",
+				    i);
+			return -1;
+		}
+	}
+
 	return 0;
 }
 
-- 
2.19.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2018-11-08 17:59:30.179161135 +0000
+++ 0006-net-virtio-user-do-not-reset-owner-when-driver-reset.patch	2018-11-08 17:59:30.048751011 +0000
@@ -1,8 +1,10 @@
-From 74dc6746a0f195907ec487df7de18a856108482f Mon Sep 17 00:00:00 2001
+From 4af6a676730e9fbebf916c17fce4bb41f7e52250 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
@@ -13,67 +15,53 @@
 
 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>
 ---
- .../net/virtio/virtio_user/virtio_user_dev.c  | 22 ++++++++++++-------
- 1 file changed, 14 insertions(+), 8 deletions(-)
+ drivers/net/virtio/virtio_user/virtio_user_dev.c | 15 ++++++++++++---
+ 1 file changed, 12 insertions(+), 3 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 8bb155d8c..3e6787a04 100644
 --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
 +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
-@@ -134,9 +134,6 @@ virtio_user_start_device(struct virtio_user_dev *dev)
- 	if (is_vhost_user_by_type(dev->path) && dev->vhostfd < 0)
- 		goto error;
+@@ -142,9 +142,6 @@ virtio_user_start_device(struct virtio_user_dev *dev)
+ 	uint64_t features;
+ 	int ret;
  
 -	/* Do not check return as already done in init, or reset in stop */
--	dev->ops->send_request(dev, VHOST_USER_SET_OWNER, NULL);
+-	vhost_user_sock(dev->vhostfd, VHOST_USER_SET_OWNER, NULL);
 -
  	/* Step 0: tell vhost to create queues */
  	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
  		goto error;
-@@ -181,7 +178,9 @@ error:
+@@ -185,6 +182,7 @@ 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);
- 	if (!dev->started)
-@@ -190,16 +189,23 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
+ 	for (i = 0; i < dev->max_queue_pairs * 2; ++i) {
+@@ -195,6 +193,17 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
  	for (i = 0; i < dev->max_queue_pairs; ++i)
- 		dev->ops->enable_qp(dev, i, 0);
+ 		vhost_user_enable_queue_pair(dev->vhostfd, 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,
++		if (vhost_user_sock(dev->vhostfd, VHOST_USER_GET_VRING_BASE,
 +					   &state) < 0) {
 +			PMD_DRV_LOG(ERR, "get_vring_base failed, index=%u\n",
 +				    i);
-+			error = -1;
-+			goto out;
++			return -1;
 +		}
- 	}
++	}
 +
- 	dev->started = false;
- out:
- 	pthread_mutex_unlock(&dev->mutex);
- 
--	return 0;
-+	return error;
+ 	return 0;
  }
  
- static inline void
 -- 
 2.19.1