int (*get_queue_stats)(const struct netdev *netdev, unsigned int queue_id,
struct netdev_queue_stats *stats);
- /* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
- * ID, its configuration, and the 'aux' specified by the caller. The order
- * of iteration is unspecified, but (when successful) each queue is visited
- * exactly once.
- *
- * 'cb' will not modify or free the 'details' argument passed in. It may
- * delete or modify the queue passed in as its 'queue_id' argument. It may
- * modify but will not delete any other queue within 'netdev'. If 'cb'
- * adds new queues, then ->dump_queues is allowed to visit some queues
- * twice or not at all.
- */
- int (*dump_queues)(const struct netdev *netdev,
- void (*cb)(unsigned int queue_id,
- const struct smap *details,
- void *aux),
- void *aux);
+ /* Attempts to begin dumping the queues in 'netdev'. On success, returns 0
+ * and initializes '*statep' with any data needed for iteration. On
+ * failure, returns a positive errno value.
+ *
+ * May be NULL if 'netdev' does not support QoS at all. */
+ int (*queue_dump_start)(const struct netdev *netdev, void **statep);
+
+ /* Attempts to retrieve another queue from 'netdev' for 'state', which was
+ * initialized by a successful call to the 'queue_dump_start' function for
+ * 'netdev'. On success, stores a queue ID into '*queue_id' and fills
+ * 'details' with the configuration of the queue with that ID. Returns EOF
+ * if the last queue has been dumped, or a positive errno value on error.
+ * This function will not be called again once it returns nonzero once for
+ * a given iteration (but the 'queue_dump_done' function will be called
+ * afterward).
+ *
+ * The caller initializes and clears 'details' before calling this
+ * function. The caller takes ownership of the string key-values pairs
+ * added to 'details'.
+ *
+ * The returned contents of 'details' should be documented as valid for the
+ * given 'type' in the "other_config" column in the "Queue" table in
+ * vswitchd/vswitch.xml (which is built as ovs-vswitchd.conf.db(8)).
+ *
+ * May be NULL if 'netdev' does not support QoS at all. */
+ int (*queue_dump_next)(const struct netdev *netdev, void *state,
+ unsigned int *queue_id, struct smap *details);
+
+ /* Releases resources from 'netdev' for 'state', which was initialized by a
+ * successful call to the 'queue_dump_start' function for 'netdev'.
+ *
+ * May be NULL if 'netdev' does not support QoS at all. */
+ int (*queue_dump_done)(const struct netdev *netdev, void *state);
/* Iterates over all of 'netdev''s queues, calling 'cb' with the queue's
* ID, its statistics, and the 'aux' specified by the caller. The order of