[4/9] vhost: make some vDPA callbacks mandatory

diff --git a/lib/librte_vhost/rte_vdpa.h b/lib/librte_vhost/rte_vdpa.h
index 3c400ee79b..a4f74211db 100644
--- a/lib/librte_vhost/rte_vdpa.h
+++ b/lib/librte_vhost/rte_vdpa.h
@@ -41,23 +41,25 @@  struct rte_vdpa_dev_addr {
  * vdpa device operations
  */
 struct rte_vdpa_dev_ops {
-	/** Get capabilities of this device */
+	/** Get capabilities of this device (Mandatory) */
 	int (*get_queue_num)(int did, uint32_t *queue_num);
 
-	/** Get supported features of this device */
+	/** Get supported features of this device (Mandatory) */
 	int (*get_features)(int did, uint64_t *features);
 
-	/** Get supported protocol features of this device */
+	/** Get supported protocol features of this device (Mandatory) */
 	int (*get_protocol_features)(int did, uint64_t *protocol_features);
 
-	/** Driver configure/close the device */
+	/** Driver configure the device (Mandatory) */
 	int (*dev_conf)(int vid);
+
+	/** Driver close the device (Mandatory) */
 	int (*dev_close)(int vid);
 
-	/** Enable/disable this vring */
+	/** Enable/disable this vring (Mandatory) */
 	int (*set_vring_state)(int vid, int vring, int state);
 
-	/** Set features when changed */
+	/** Set features when changed (Mandatory) */
 	int (*set_features)(int vid);
 
 	/** Destination operations when migration done */
diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index bb8d0d7801..23f3448d2c 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -707,7 +707,7 @@  rte_vhost_driver_get_features(const char *path, uint64_t *features)
 
 	did = vsocket->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
-	if (!vdpa_dev || !vdpa_dev->ops->get_features) {
+	if (!vdpa_dev) {
 		*features = vsocket->features;
 		goto unlock_exit;
 	}
@@ -762,7 +762,7 @@  rte_vhost_driver_get_protocol_features(const char *path,
 
 	did = vsocket->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
-	if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
+	if (!vdpa_dev) {
 		*protocol_features = vsocket->protocol_features;
 		goto unlock_exit;
 	}
@@ -804,7 +804,7 @@  rte_vhost_driver_get_queue_num(const char *path, uint32_t *queue_num)
 
 	did = vsocket->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
-	if (!vdpa_dev || !vdpa_dev->ops->get_queue_num) {
+	if (!vdpa_dev) {
 		*queue_num = VHOST_MAX_QUEUE_PAIRS;
 		goto unlock_exit;
 	}
diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c
index b2b2a105f1..e5e949f6d3 100644
--- a/lib/librte_vhost/vdpa.c
+++ b/lib/librte_vhost/vdpa.c
@@ -66,6 +66,16 @@  rte_vdpa_register_device(struct rte_vdpa_dev_addr *addr,
 	if (i == MAX_VHOST_DEVICE)
 		return -1;
 
+	/* Check mandatory ops are implemented */
+	if (!ops->get_queue_num || !ops->get_features ||
+			!ops->get_protocol_features || !ops->dev_conf ||
+			!ops->dev_close || !ops->set_vring_state ||
+			!ops->set_features) {
+		VHOST_LOG_CONFIG(ERR,
+				"Some mandatory vDPA ops aren't implemented\n");
+		return -1;
+	}
+
 	snprintf(device_name, sizeof(device_name), "vdpa-dev-%d", i);
 	dev = rte_zmalloc(device_name, sizeof(struct rte_vdpa_device),
 			RTE_CACHE_LINE_SIZE);
diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c
index fd8ba1be2d..7b5c9b3537 100644
--- a/lib/librte_vhost/vhost.c
+++ b/lib/librte_vhost/vhost.c
@@ -649,7 +649,7 @@  vhost_destroy_device_notify(struct virtio_net *dev)
 	if (dev->flags & VIRTIO_DEV_RUNNING) {
 		did = dev->vdpa_dev_id;
 		vdpa_dev = rte_vdpa_get_device(did);
-		if (vdpa_dev && vdpa_dev->ops->dev_close)
+		if (vdpa_dev)
 			vdpa_dev->ops->dev_close(dev->vid);
 		dev->flags &= ~VIRTIO_DEV_RUNNING;
 		dev->notify_ops->destroy_device(dev->vid);
diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index f5800bd9c1..7a43c2fae7 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -386,7 +386,7 @@  vhost_user_set_features(struct virtio_net **pdev, struct VhostUserMsg *msg,
 
 	did = dev->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
-	if (vdpa_dev && vdpa_dev->ops->set_features)
+	if (vdpa_dev)
 		vdpa_dev->ops->set_features(dev->vid);
 
 	return RTE_VHOST_MSG_RESULT_OK;
@@ -1972,7 +1972,7 @@  vhost_user_set_vring_enable(struct virtio_net **pdev,
 
 	did = dev->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
-	if (vdpa_dev && vdpa_dev->ops->set_vring_state)
+	if (vdpa_dev)
 		vdpa_dev->ops->set_vring_state(dev->vid, index, enable);
 
 	if (dev->notify_ops->vring_state_changed)
@@ -2809,8 +2809,7 @@  vhost_user_msg_handler(int vid, int fd)
 
 	if (!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED) &&
 			request == VHOST_USER_SET_VRING_CALL) {
-		if (vdpa_dev->ops->dev_conf)
-			vdpa_dev->ops->dev_conf(dev->vid);
+		vdpa_dev->ops->dev_conf(dev->vid);
 
 		dev->flags |= VIRTIO_DEV_VDPA_CONFIGURED;
 	}