Merge pull request #1646 from amzn/cq_doorbell

efa: Extend DV query CQ to return doorbell

Author: rleon

providers/efa/efadv.h

@@ -127,6 +127,7 @@ struct efadv_cq_attr {
 	uint8_t *buffer;
 	uint32_t entry_size;
 	uint32_t num_entries;
+	uint32_t *doorbell;
 };
 
 int efadv_query_cq(struct ibv_cq *ibvcq, struct efadv_cq_attr *attr, uint32_t inlen);

providers/efa/man/efadv_query_cq.3.md

@@ -33,6 +33,7 @@ struct efadv_cq_attr {
 	uint8_t *buffer;
 	uint32_t entry_size;
 	uint32_t num_entries;
+	uint32_t *doorbell;
 };
 ```
 
@@ -51,6 +52,10 @@ struct efadv_cq_attr {
 *num_entries*
 :	Maximal number of entries in the completion queue.
 
+*doorbell*
+:	Reverse doorbell used to update the device of polled entries and to
+	request notifications. NULL when not in use for this Completion Queue.
+
 # RETURN VALUE
 
 **efadv_query_cq()** returns 0 on success, or the value of errno on failure

providers/efa/verbs.c

@@ -1326,6 +1326,9 @@ int efadv_query_cq(struct ibv_cq *ibvcq, struct efadv_cq_attr *attr, uint32_t in
 	attr->entry_size = cq->cqe_size;
 	attr->num_entries = ibvcq->cqe;
 
+	if (vext_field_avail(typeof(*attr), doorbell, inlen))
+		attr->doorbell = cq->db;
+
 	return 0;
 }