[dpdk-dev] [PATCH 6/7] net/virtio: split virtio-user start

[Maxime Coquelin <maxime.coquelin@redhat.com>]

Move feature bit settings in device start out as an standalone
function, so that feature bit could be negotiated at device
feature_ok status.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 .../net/virtio/virtio_user/virtio_user_dev.c  | 50 ++++++++++++-------
 .../net/virtio/virtio_user/virtio_user_dev.h  |  1 +
 drivers/net/virtio/virtio_user_ethdev.c       |  4 ++
 3 files changed, 37 insertions(+), 18 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index 97baa243cd..2e097a95ea 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -165,25 +165,11 @@ virtio_user_backend_type(const char *path)
 }
 
 int
-virtio_user_start_device(struct virtio_user_dev *dev)
+virtio_user_dev_set_features(struct virtio_user_dev *dev)
 {
 	uint64_t features;
-	int ret;
+	int ret = -1;
 
-	/*
-	 * XXX workaround!
-	 *
-	 * We need to make sure that the locks will be
-	 * taken in the correct order to avoid deadlocks.
-	 *
-	 * Before releasing this lock, this thread should
-	 * not trigger any memory hotplug events.
-	 *
-	 * This is a temporary workaround, and should be
-	 * replaced when we get proper supports from the
-	 * memory subsystem in the future.
-	 */
-	rte_mcfg_mem_read_lock();
 	pthread_mutex_lock(&dev->mutex);
 
 	if (virtio_user_backend_type(dev->path) ==
@@ -194,10 +180,8 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	if (virtio_user_queue_setup(dev, virtio_user_create_queue) < 0)
 		goto error;
 
-	/* Step 1: negotiate protocol features & set features */
 	features = dev->features;
 
-
 	/* Strip VIRTIO_NET_F_MAC, as MAC address is handled in vdev init */
 	features &= ~(1ull << VIRTIO_NET_F_MAC);
 	/* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
@@ -207,6 +191,36 @@ virtio_user_start_device(struct virtio_user_dev *dev)
 	if (ret < 0)
 		goto error;
 	PMD_DRV_LOG(INFO, "set features: %" PRIx64, features);
+error:
+	pthread_mutex_unlock(&dev->mutex);
+
+	return ret;
+}
+
+int
+virtio_user_start_device(struct virtio_user_dev *dev)
+{
+	int ret;
+
+	/*
+	 * XXX workaround!
+	 *
+	 * We need to make sure that the locks will be
+	 * taken in the correct order to avoid deadlocks.
+	 *
+	 * Before releasing this lock, this thread should
+	 * not trigger any memory hotplug events.
+	 *
+	 * This is a temporary workaround, and should be
+	 * replaced when we get proper supports from the
+	 * memory subsystem in the future.
+	 */
+	rte_mcfg_mem_read_lock();
+	pthread_mutex_lock(&dev->mutex);
+
+	if (virtio_user_backend_type(dev->path) ==
+		VIRTIO_USER_BACKEND_VHOST_USER && dev->vhostfd < 0)
+		goto error;
 
 	/* Step 2: share memory regions */
 	ret = dev->ops->send_request(dev, VHOST_USER_SET_MEM_TABLE, NULL);
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.h b/drivers/net/virtio/virtio_user/virtio_user_dev.h
index 4bb7cdbd26..68ec9dc3f1 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.h
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.h
@@ -69,6 +69,7 @@ struct virtio_user_dev {
 };
 
 enum virtio_user_backend_type virtio_user_backend_type(const char *path);
+int virtio_user_dev_set_features(struct virtio_user_dev *dev);
 int virtio_user_start_device(struct virtio_user_dev *dev);
 int virtio_user_stop_device(struct virtio_user_dev *dev);
 int virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 2163d0e30d..91eebbedab 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -266,7 +266,11 @@ static void
 virtio_user_set_status(struct virtio_hw *hw, uint8_t status)
 {
 	struct virtio_user_dev *dev = virtio_user_get_dev(hw);
+	uint8_t old_status = dev->status;
 
+	if (status & VIRTIO_CONFIG_STATUS_FEATURES_OK &&
+			~old_status & VIRTIO_CONFIG_STATUS_FEATURES_OK)
+		virtio_user_dev_set_features(dev);
 	if (status & VIRTIO_CONFIG_STATUS_DRIVER_OK)
 		virtio_user_start_device(dev);
 	else if (status == VIRTIO_CONFIG_STATUS_RESET)
-- 
2.26.2