vhost: introduce wrappers for some vDPA ops

This patch is preliminary work to make the vDPA device
structure opaque to the user application. Some callbacks
of the vDPA devices are used to query capabilities before
attaching to a Vhost port. This patch introduces wrappers
for these ops.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Adrián Moreno <amorenoz@redhat.com>

lib/librte_vhost/rte_vdpa.h

@@ -226,6 +226,78 @@ __rte_experimental
 int
 rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Get number of queue pairs supported by the vDPA device
+ *
+ * @param dev
+ *  vDP device pointer
+ * @param queue_num
+ *  pointer on where the number of queue is stored
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vdpa_get_queue_num(struct rte_vdpa_device *dev, uint32_t *queue_num);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Get the Virtio features supported by the vDPA device
+ *
+ * @param dev
+ *  vDP device pointer
+ * @param features
+ *  pointer on where the supported features are stored
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vdpa_get_features(struct rte_vdpa_device *dev, uint64_t *features);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Get the Vhost-user protocol features supported by the vDPA device
+ *
+ * @param dev
+ *  vDP device pointer
+ * @param features
+ *  pointer on where the supported protocol features are stored
+ * @return
+ *  0 on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vdpa_get_protocol_features(struct rte_vdpa_device *dev, uint64_t *features);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice
+ *
+ * Synchronize the used ring from mediated ring to guest, log dirty
+ * page for each writeable buffer, caller should handle the used
+ * ring logging before device stop.
+ *
+ * @param vid
+ *  vhost device id
+ * @param qid
+ *  vhost queue id
+ * @param vring_m
+ *  mediated virtio ring pointer
+ * @return
+ *  number of synced used entries on success, -1 on failure
+ */
+__rte_experimental
+int
+rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m);
+
 /**
  * @warning
  * @b EXPERIMENTAL: this API may change without prior notice

lib/librte_vhost/rte_vhost_version.map

@@ -69,4 +69,7 @@ EXPERIMENTAL {
 	rte_vhost_slave_config_change;
 	rte_vdpa_find_device_by_name;
 	rte_vdpa_get_rte_device;
+	rte_vdpa_get_queue_num;
+	rte_vdpa_get_features;
+	rte_vdpa_get_protocol_features;
 };

lib/librte_vhost/vdpa.c

@@ -229,6 +229,34 @@ rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
 	return -1;
 }
 
+int
+rte_vdpa_get_queue_num(struct rte_vdpa_device *dev, uint32_t *queue_num)
+{
+	if (dev == NULL || dev->ops == NULL || dev->ops->get_queue_num == NULL)
+		return -1;
+
+	return dev->ops->get_queue_num(dev, queue_num);
+}
+
+int
+rte_vdpa_get_features(struct rte_vdpa_device *dev, uint64_t *features)
+{
+	if (dev == NULL || dev->ops == NULL || dev->ops->get_features == NULL)
+		return -1;
+
+	return dev->ops->get_features(dev, features);
+}
+
+int
+rte_vdpa_get_protocol_features(struct rte_vdpa_device *dev, uint64_t *features)
+{
+	if (dev == NULL || dev->ops == NULL ||
+			dev->ops->get_protocol_features == NULL)
+		return -1;
+
+	return dev->ops->get_protocol_features(dev, features);
+}
+
 int
 rte_vdpa_get_stats_names(struct rte_vdpa_device *dev,
 		struct rte_vdpa_stat_name *stats_names,