[dpdk-dev] [PATCH v2 3/4] vdpa/mlx5: support virtio queue statistics get

[Matan Azrad]

Add support for statistics operations.

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>
---
 doc/guides/vdpadevs/features/mlx5.ini |  1 +
 drivers/vdpa/mlx5/mlx5_vdpa.c         | 85 +++++++++++++++++++++++++++++++++
 drivers/vdpa/mlx5/mlx5_vdpa.h         | 45 ++++++++++++++++++
 drivers/vdpa/mlx5/mlx5_vdpa_virtq.c   | 90 +++++++++++++++++++++++++++++++++++
 4 files changed, 221 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 1113d6c..a80e3f4 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
@@ -8,6 +8,7 @@
 #include <rte_errno.h>
 #include <rte_bus_pci.h>
 #include <rte_pci.h>
+#include <rte_string_fns.h>
 
 #include <mlx5_glue.h>
 #include <mlx5_common.h>
@@ -274,6 +275,85 @@
 	return 0;
 }
 
+static int
+mlx5_vdpa_get_stats_names(int did, struct rte_vdpa_stat_name *stats_names,
+			  unsigned int size)
+{
+	static const char *mlx5_vdpa_stats_names[MLX5_VDPA_STATS_MAX] = {
+		"received_descriptors",
+		"completed_descriptors",
+		"bad descriptor errors",
+		"exceed max chain",
+		"invalid buffer",
+		"completion errors",
+	};
+	struct mlx5_vdpa_priv *priv = mlx5_vdpa_find_priv_resource_by_did(did);
+	unsigned int i;
+
+	if (priv == NULL) {
+		DRV_LOG(ERR, "Invalid device id: %d.", did);
+		return -ENODEV;
+	}
+	if (!stats_names)
+		return MLX5_VDPA_STATS_MAX;
+	size = RTE_MIN(size, (unsigned int)MLX5_VDPA_STATS_MAX);
+	for (i = 0; i < size; ++i)
+		strlcpy(stats_names[i].name, mlx5_vdpa_stats_names[i],
+			RTE_VDPA_STATS_NAME_SIZE);
+	return size;
+}
+
+static int
+mlx5_vdpa_get_stats(int did, int qid, struct rte_vdpa_stat *stats,
+		    unsigned int n)
+{
+	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, n);
+}
+
+static int
+mlx5_vdpa_reset_stats(int did, int qid)
+{
+	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_reset(priv, qid);
+}
+
 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 +366,9 @@
 	.get_vfio_group_fd = NULL,
 	.get_vfio_device_fd = mlx5_vdpa_get_device_fd,
 	.get_notify_area = mlx5_vdpa_get_notify_area,
+	.get_stats_names = mlx5_vdpa_get_stats_names,
+	.get_stats = mlx5_vdpa_get_stats,
+	.reset_stats = mlx5_vdpa_reset_stats,
 };
 
 static struct ibv_device *
@@ -489,6 +572,8 @@
 		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..80b4c4b 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;
@@ -83,6 +84,7 @@ struct mlx5_vdpa_virtq {
 		uint32_t size;
 	} umems[3];
 	struct rte_intr_handle intr_handle;
+	struct mlx5_devx_virtio_q_couners_attr reset;
 };
 
 struct mlx5_vdpa_steer {
@@ -127,6 +129,16 @@ struct mlx5_vdpa_priv {
 	struct mlx5_vdpa_virtq virtqs[];
 };
 
+enum {
+	MLX5_VDPA_STATS_RECEIVED_DESCRIPTORS,
+	MLX5_VDPA_STATS_COMPLETED_DESCRIPTORS,
+	MLX5_VDPA_STATS_BAD_DESCRIPTOR_ERRORS,
+	MLX5_VDPA_STATS_EXCEED_MAX_CHAIN,
+	MLX5_VDPA_STATS_INVALID_BUFFER,
+	MLX5_VDPA_STATS_COMPLETION_ERRORS,
+	MLX5_VDPA_STATS_MAX
+};
+
 /*
  * Check whether virtq is for traffic receive.
  * According to VIRTIO_NET Spec the virtqueues index identity its type by:
@@ -352,4 +364,37 @@ 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 array to fill.
+ * @param n
+ *   The number of elements in @p stats array.
+ *
+ * @return
+ *   A negative value on error, otherwise the number of entries filled in the
+ *   @p stats array.
+ */
+int
+mlx5_vdpa_virtq_stats_get(struct mlx5_vdpa_priv *priv, int qid,
+			  struct rte_vdpa_stat *stats, unsigned int n);
+
+/**
+ * Reset virtq statistics.
+ *
+ * @param[in] priv
+ *   The vdpa driver private structure.
+ * @param[in] qid
+ *   The virtq index.
+ *
+ * @return
+ *   A negative value on error, otherwise 0.
+ */
+int
+mlx5_vdpa_virtq_stats_reset(struct mlx5_vdpa_priv *priv, int qid);
 #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 bd48460..d57ed59 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
@@ -72,6 +72,11 @@
 			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;
+	}
+	memset(&virtq->reset, 0, sizeof(virtq->reset));
 	if (virtq->eqp.fw_qp)
 		mlx5_vdpa_event_qp_destroy(&virtq->eqp);
 	return 0;
@@ -205,6 +210,16 @@
 		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 +
@@ -455,3 +470,78 @@
 	}
 	return 0;
 }
+
+int
+mlx5_vdpa_virtq_stats_get(struct mlx5_vdpa_priv *priv, int qid,
+			  struct rte_vdpa_stat *stats, unsigned int n)
+{
+	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;
+	}
+	ret = (int)RTE_MIN(n, (unsigned int)MLX5_VDPA_STATS_MAX);
+	if (ret == MLX5_VDPA_STATS_RECEIVED_DESCRIPTORS)
+		return ret;
+	stats[MLX5_VDPA_STATS_RECEIVED_DESCRIPTORS] = (struct rte_vdpa_stat) {
+		.id = MLX5_VDPA_STATS_RECEIVED_DESCRIPTORS,
+		.value = attr.received_desc - virtq->reset.received_desc,
+	};
+	if (ret == MLX5_VDPA_STATS_COMPLETED_DESCRIPTORS)
+		return ret;
+	stats[MLX5_VDPA_STATS_COMPLETED_DESCRIPTORS] = (struct rte_vdpa_stat) {
+		.id = MLX5_VDPA_STATS_COMPLETED_DESCRIPTORS,
+		.value = attr.completed_desc - virtq->reset.completed_desc,
+	};
+	if (ret == MLX5_VDPA_STATS_BAD_DESCRIPTOR_ERRORS)
+		return ret;
+	stats[MLX5_VDPA_STATS_BAD_DESCRIPTOR_ERRORS] = (struct rte_vdpa_stat) {
+		.id = MLX5_VDPA_STATS_BAD_DESCRIPTOR_ERRORS,
+		.value = attr.bad_desc_errors - virtq->reset.bad_desc_errors,
+	};
+	if (ret == MLX5_VDPA_STATS_EXCEED_MAX_CHAIN)
+		return ret;
+	stats[MLX5_VDPA_STATS_EXCEED_MAX_CHAIN] = (struct rte_vdpa_stat) {
+		.id = MLX5_VDPA_STATS_EXCEED_MAX_CHAIN,
+		.value = attr.exceed_max_chain - virtq->reset.exceed_max_chain,
+	};
+	if (ret == MLX5_VDPA_STATS_INVALID_BUFFER)
+		return ret;
+	stats[MLX5_VDPA_STATS_INVALID_BUFFER] = (struct rte_vdpa_stat) {
+		.id = MLX5_VDPA_STATS_INVALID_BUFFER,
+		.value = attr.invalid_buffer - virtq->reset.invalid_buffer,
+	};
+	if (ret == MLX5_VDPA_STATS_COMPLETION_ERRORS)
+		return ret;
+	stats[MLX5_VDPA_STATS_COMPLETION_ERRORS] = (struct rte_vdpa_stat) {
+		.id = MLX5_VDPA_STATS_COMPLETION_ERRORS,
+		.value = attr.error_cqes - virtq->reset.error_cqes,
+	};
+	return ret;
+}
+
+int
+mlx5_vdpa_virtq_stats_reset(struct mlx5_vdpa_priv *priv, int qid)
+{
+	struct mlx5_vdpa_virtq *virtq = &priv->virtqs[qid];
+	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,
+						    &virtq->reset);
+	if (ret)
+		DRV_LOG(ERR, "Failed to read virtq %d reset stats from HW.",
+			qid);
+	return ret;
+}
-- 
1.8.3.1