From: Matan Azrad <matan@mellanox.com>
Date: Mon, 29 Jun 2020 14:08:18 +0000 (+0000)
Subject: vhost: improve device readiness notifications
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=d0fcc38f5fa4;p=dpdk.git

vhost: improve device readiness notifications

Some guest drivers may not configure disabled virtio queues.

In this case, the vhost management never notifies the application and
the vDPA device readiness because it waits to the device to be ready.

The current ready state means that all the virtio queues should be
configured regardless the enablement status.

In order to support this case, this patch changes the ready state:
The device is ready when at least 1 queue pair is configured and
enabled.

So, now, the application and vDPA driver are notifies when the first
queue pair is configured and enabled.

Also the queue notifications will be triggered according to the new
ready definition.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
---

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 941a42637e..a0fe703eec 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -152,6 +152,7 @@ struct vhost_virtqueue {
 	int			backend;
 	int			enabled;
 	int			access_ok;
+	int			ready;
 	rte_spinlock_t		access_lock;
 
 	/* Used to notify the guest (trigger interrupt) */
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 4349506719..4ca872842b 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -228,6 +228,20 @@ vhost_backend_cleanup(struct virtio_net *dev)
 	dev->postcopy_listening = 0;
 }
 
+static void
+vhost_user_notify_queue_state(struct virtio_net *dev, uint16_t index,
+			      int enable)
+{
+	struct rte_vdpa_device *vdpa_dev = dev->vdpa_dev;
+
+	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
+		vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
+
+	if (dev->notify_ops->vring_state_changed)
+		dev->notify_ops->vring_state_changed(dev->vid,
+				index, enable);
+}
+
 /*
  * This function just returns success at the moment unless
  * the device hasn't been initialised.
@@ -1304,27 +1318,31 @@ vq_is_ready(struct virtio_net *dev, struct vhost_virtqueue *vq)
 
 	return rings_ok &&
 	       vq->kickfd != VIRTIO_UNINITIALIZED_EVENTFD &&
-	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD;
+	       vq->callfd != VIRTIO_UNINITIALIZED_EVENTFD &&
+	       vq->enabled;
 }
 
+#define VIRTIO_DEV_NUM_VQS_TO_BE_READY 2u
+
 static int
 virtio_is_ready(struct virtio_net *dev)
 {
 	struct vhost_virtqueue *vq;
 	uint32_t i;
 
-	if (dev->nr_vring == 0)
+	if (dev->nr_vring < VIRTIO_DEV_NUM_VQS_TO_BE_READY)
 		return 0;
 
-	for (i = 0; i < dev->nr_vring; i++) {
+	for (i = 0; i < VIRTIO_DEV_NUM_VQS_TO_BE_READY; i++) {
 		vq = dev->virtqueue[i];
 
 		if (!vq_is_ready(dev, vq))
 			return 0;
 	}
 
-	VHOST_LOG_CONFIG(INFO,
-		"virtio is now ready for processing.\n");
+	if (!(dev->flags & VIRTIO_DEV_RUNNING))
+		VHOST_LOG_CONFIG(INFO,
+			"virtio is now ready for processing.\n");
 	return 1;
 }
 
@@ -1968,7 +1986,6 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
 	struct virtio_net *dev = *pdev;
 	int enable = (int)msg->payload.state.num;
 	int index = (int)msg->payload.state.index;
-	struct rte_vdpa_device *vdpa_dev;
 
 	if (validate_msg_fds(msg, 0) != 0)
 		return RTE_VHOST_MSG_RESULT_ERR;
@@ -1977,14 +1994,6 @@ vhost_user_set_vring_enable(struct virtio_net **pdev,
 		"set queue enable: %d to qp idx: %d\n",
 		enable, index);
 
-	vdpa_dev = dev->vdpa_dev;
-	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
-		vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
-
-	if (dev->notify_ops->vring_state_changed)
-		dev->notify_ops->vring_state_changed(dev->vid,
-				index, enable);
-
 	/* On disable, rings have to be stopped being processed. */
 	if (!enable && dev->dequeue_zero_copy)
 		drain_zmbuf_list(dev->virtqueue[index]);
@@ -2611,6 +2620,7 @@ vhost_user_msg_handler(int vid, int fd)
 	int unlock_required = 0;
 	bool handled;
 	int request;
+	uint32_t i;
 
 	dev = get_device(vid);
 	if (dev == NULL)
@@ -2786,6 +2796,17 @@ skip_to_post_handle:
 		return -1;
 	}
 
+	for (i = 0; i < dev->nr_vring; i++) {
+		struct vhost_virtqueue *vq = dev->virtqueue[i];
+		bool cur_ready = vq_is_ready(dev, vq);
+
+		if (cur_ready != (vq && vq->ready)) {
+			vhost_user_notify_queue_state(dev, i, cur_ready);
+			vq->ready = cur_ready;
+		}
+	}
+
+
 	if (!(dev->flags & VIRTIO_DEV_RUNNING) && virtio_is_ready(dev)) {
 		dev->flags |= VIRTIO_DEV_READY;
 
@@ -2802,8 +2823,7 @@ skip_to_post_handle:
 
 	vdpa_dev = dev->vdpa_dev;
 	if (vdpa_dev && virtio_is_ready(dev) &&
-			!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED) &&
-			msg.request.master == VHOST_USER_SET_VRING_CALL) {
+	    !(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)) {
 		if (vdpa_dev->ops->dev_conf)
 			vdpa_dev->ops->dev_conf(dev->vid);
 		dev->flags |= VIRTIO_DEV_VDPA_CONFIGURED;