[dpdk-dev] [PATCH 3/4] vdpa/mlx5: support virtio queue statistics get

[Matan Azrad]

Add support for stats_get operation.

A DevX counter object is allocated per virtq in order to manage the
virtq statistics.

The counter object is allocated before the virtq creation and destroyed
after it, so the statistics are valid only in the life time of the
virtq.

Signed-off-by: Matan Azrad <matan at mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo at mellanox.com>
---
 doc/guides/vdpadevs/features/mlx5.ini |  1 +
 drivers/vdpa/mlx5/mlx5_vdpa.c         | 28 +++++++++++++++++++++++
 drivers/vdpa/mlx5/mlx5_vdpa.h         | 16 +++++++++++++
 drivers/vdpa/mlx5/mlx5_vdpa_virtq.c   | 43 +++++++++++++++++++++++++++++++++++
 4 files changed, 88 insertions(+)

diff --git a/doc/guides/vdpadevs/features/mlx5.ini b/doc/guides/vdpadevs/features/mlx5.ini
index 1da9c1b..788d4e0 100644
--- a/doc/guides/vdpadevs/features/mlx5.ini
+++ b/doc/guides/vdpadevs/features/mlx5.ini
@@ -17,6 +17,7 @@ packed               = Y
 proto mq             = Y
 proto log shmfd      = Y
 proto host notifier  = Y
+queue statistics     = Y
 Other kdrv           = Y
 ARMv8                = Y
 Power8               = Y
diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.c b/drivers/vdpa/mlx5/mlx5_vdpa.c
index fe17ced..91d8f96 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
@@ -274,6 +274,31 @@
 	return 0;
 }
 
+static int
+mlx5_vdpa_get_stats(int did, int qid, struct rte_vdpa_queue_stats *stats)
+{
+	struct mlx5_vdpa_priv *priv = mlx5_vdpa_find_priv_resource_by_did(did);
+
+	if (priv == NULL) {
+		DRV_LOG(ERR, "Invalid device id: %d.", did);
+		return -ENODEV;
+	}
+	if (!priv->configured) {
+		DRV_LOG(ERR, "Device %d was not configured.", did);
+		return -ENODATA;
+	}
+	if (qid >= (int)priv->nr_virtqs) {
+		DRV_LOG(ERR, "Too big vring id: %d.", qid);
+		return -E2BIG;
+	}
+	if (!priv->caps.queue_counters_valid) {
+		DRV_LOG(ERR, "Virtq statistics is not supported for device %d.",
+			did);
+		return -ENOTSUP;
+	}
+	return mlx5_vdpa_virtq_stats_get(priv, qid, stats);
+}
+
 static struct rte_vdpa_dev_ops mlx5_vdpa_ops = {
 	.get_queue_num = mlx5_vdpa_get_queue_num,
 	.get_features = mlx5_vdpa_get_vdpa_features,
@@ -286,6 +311,7 @@
 	.get_vfio_group_fd = NULL,
 	.get_vfio_device_fd = mlx5_vdpa_get_device_fd,
 	.get_notify_area = mlx5_vdpa_get_notify_area,
+	.get_stats = mlx5_vdpa_get_stats,
 };
 
 static struct ibv_device *
@@ -489,6 +515,8 @@
 		rte_errno = ENOTSUP;
 		goto error;
 	}
+	if (!attr.vdpa.queue_counters_valid)
+		DRV_LOG(DEBUG, "No capability to support virtq statistics.");
 	priv = rte_zmalloc("mlx5 vDPA device private", sizeof(*priv) +
 			   sizeof(struct mlx5_vdpa_virtq) *
 			   attr.vdpa.max_num_virtio_queues * 2,
diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.h b/drivers/vdpa/mlx5/mlx5_vdpa.h
index fcc216a..35b2be1 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.h
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.h
@@ -76,6 +76,7 @@ struct mlx5_vdpa_virtq {
 	uint16_t vq_size;
 	struct mlx5_vdpa_priv *priv;
 	struct mlx5_devx_obj *virtq;
+	struct mlx5_devx_obj *counters;
 	struct mlx5_vdpa_event_qp eqp;
 	struct {
 		struct mlx5dv_devx_umem *obj;
@@ -352,4 +353,19 @@ int mlx5_vdpa_dirty_bitmap_set(struct mlx5_vdpa_priv *priv, uint64_t log_base,
  */
 int mlx5_vdpa_virtq_stop(struct mlx5_vdpa_priv *priv, int index);
 
+/**
+ * Get virtq statistics.
+ *
+ * @param[in] priv
+ *   The vdpa driver private structure.
+ * @param[in] qid
+ *   The virtq index.
+ * @param stats
+ *   The virtq statistics structure to fill.
+ *
+ * @return
+ *   0 on success and @p stats is updated, a negative value otherwise.
+ */
+int mlx5_vdpa_virtq_stats_get(struct mlx5_vdpa_priv *priv, int qid,
+			      struct rte_vdpa_queue_stats *stats);
 #endif /* RTE_PMD_MLX5_VDPA_H_ */
diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
index defb9e1..9fea6e9 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
@@ -72,6 +72,10 @@
 			rte_free(virtq->umems[i].buf);
 	}
 	memset(&virtq->umems, 0, sizeof(virtq->umems));
+	if (virtq->counters) {
+		claim_zero(mlx5_devx_cmd_destroy(virtq->counters));
+		virtq->counters = NULL;
+	}
 	if (virtq->eqp.fw_qp)
 		mlx5_vdpa_event_qp_destroy(&virtq->eqp);
 	return 0;
@@ -205,6 +209,16 @@
 		DRV_LOG(INFO, "Virtq %d is, for sure, working by poll mode, no"
 			" need event QPs and event mechanism.", index);
 	}
+	if (priv->caps.queue_counters_valid) {
+		virtq->counters = mlx5_devx_cmd_create_virtio_q_counters
+								    (priv->ctx);
+		if (!virtq->counters) {
+			DRV_LOG(ERR, "Failed to create virtq couners for virtq"
+				" %d.", index);
+			goto error;
+		}
+		attr.counters_obj_id = virtq->counters->id;
+	}
 	/* Setup 3 UMEMs for each virtq. */
 	for (i = 0; i < RTE_DIM(virtq->umems); ++i) {
 		virtq->umems[i].size = priv->caps.umems[i].a * vq.size +
@@ -448,3 +462,32 @@
 	}
 	return 0;
 }
+
+int
+mlx5_vdpa_virtq_stats_get(struct mlx5_vdpa_priv *priv, int qid,
+			  struct rte_vdpa_queue_stats *stats)
+{
+	struct mlx5_vdpa_virtq *virtq = &priv->virtqs[qid];
+	struct mlx5_devx_virtio_q_couners_attr attr = {0};
+	int ret;
+
+	if (!virtq->virtq) {
+		DRV_LOG(ERR, "Failed to read virtq %d statistics - virtq "
+			"synchronization failed.", qid);
+	}
+	MLX5_ASSERT(virtq->counters);
+	ret = mlx5_devx_cmd_query_virtio_q_counters(virtq->counters, &attr);
+	if (ret) {
+		DRV_LOG(ERR, "Failed to read virtq %d stats from HW.", qid);
+		return ret;
+	}
+	*stats = (struct rte_vdpa_queue_stats) {
+			.received_desc = attr.received_desc,
+			.completed_desc = attr.completed_desc,
+			.bad_desc = attr.bad_desc_errors,
+			.exceed_max_chain = attr.exceed_max_chain,
+			.invalid_buffer = attr.invalid_buffer,
+			.errors = attr.error_cqes,
+		};
+	return 0;
+}
-- 
1.8.3.1