[PATCH v3 1/2] net/mlx5: fix reported Rx/Tx desc limits

[Igor Gutorov <igootorov@gmail.com>]

Currently, `rte_eth_dev_info.rx_desc_lim.nb_max` as well as
`rte_eth_dev_info.tx_desc_lim.nb_max` shows 65535 as the limit,
which results in a few problems:

* It is not the actual Rx/Tx queue limit
* Allocating an Rx queue and passing `rx_desc_lim.nb_max` results in an
  integer overflow and 0 ring size:

```
rte_eth_rx_queue_setup(0, 0, rx_desc_lim.nb_max, 0, NULL, mb_pool);
```

Which overflows ring size and generates the following log:
```
mlx5_net: port 0 increased number of descriptors in Rx queue 0 to the
next power of two (0)
```
The same holds for allocating a Tx queue.

Fixes: e60fbd5b24fc ("mlx5: add device configure/start/stop")
Cc: stable@dpdk.org

Signed-off-by: Igor Gutorov <igootorov@gmail.com>
---
 drivers/common/mlx5/mlx5_devx_cmds.c | 1 +
 drivers/common/mlx5/mlx5_devx_cmds.h | 1 +
 drivers/net/mlx5/mlx5_ethdev.c       | 4 ++++
 drivers/net/mlx5/mlx5_rxq.c          | 8 ++++++++
 drivers/net/mlx5/mlx5_txq.c          | 8 ++++++++
 5 files changed, 22 insertions(+)

diff --git a/drivers/common/mlx5/mlx5_devx_cmds.c b/drivers/common/mlx5/mlx5_devx_cmds.c
index 9710dcedd3..a75f011750 100644
--- a/drivers/common/mlx5/mlx5_devx_cmds.c
+++ b/drivers/common/mlx5/mlx5_devx_cmds.c
@@ -1027,6 +1027,7 @@ mlx5_devx_cmd_query_hca_attr(void *ctx,
 	attr->log_max_qp = MLX5_GET(cmd_hca_cap, hcattr, log_max_qp);
 	attr->log_max_cq_sz = MLX5_GET(cmd_hca_cap, hcattr, log_max_cq_sz);
 	attr->log_max_qp_sz = MLX5_GET(cmd_hca_cap, hcattr, log_max_qp_sz);
+	attr->log_max_wq_sz = MLX5_GET(cmd_hca_cap, hcattr, log_max_wq_sz);
 	attr->log_max_mrw_sz = MLX5_GET(cmd_hca_cap, hcattr, log_max_mrw_sz);
 	attr->log_max_pd = MLX5_GET(cmd_hca_cap, hcattr, log_max_pd);
 	attr->log_max_srq = MLX5_GET(cmd_hca_cap, hcattr, log_max_srq);
diff --git a/drivers/common/mlx5/mlx5_devx_cmds.h b/drivers/common/mlx5/mlx5_devx_cmds.h
index 6cf7999c46..2ad9e5414f 100644
--- a/drivers/common/mlx5/mlx5_devx_cmds.h
+++ b/drivers/common/mlx5/mlx5_devx_cmds.h
@@ -267,6 +267,7 @@ struct mlx5_hca_attr {
 	struct mlx5_hca_flow_attr flow;
 	struct mlx5_hca_flex_attr flex;
 	struct mlx5_hca_crypto_mmo_attr crypto_mmo;
+	uint8_t log_max_wq_sz;
 	int log_max_qp_sz;
 	int log_max_cq_sz;
 	int log_max_qp;
diff --git a/drivers/net/mlx5/mlx5_ethdev.c b/drivers/net/mlx5/mlx5_ethdev.c
index 6a678d6dcc..cac55f7a72 100644
--- a/drivers/net/mlx5/mlx5_ethdev.c
+++ b/drivers/net/mlx5/mlx5_ethdev.c
@@ -359,6 +359,10 @@ mlx5_dev_infos_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *info)
 	info->flow_type_rss_offloads = ~MLX5_RSS_HF_MASK;
 	mlx5_set_default_params(dev, info);
 	mlx5_set_txlimit_params(dev, info);
+	info->rx_desc_lim.nb_max =
+		1 << priv->sh->cdev->config.hca_attr.log_max_wq_sz;
+	info->tx_desc_lim.nb_max =
+		1 << priv->sh->cdev->config.hca_attr.log_max_wq_sz;
 	if (priv->sh->cdev->config.hca_attr.mem_rq_rmp &&
 	    priv->obj_ops.rxq_obj_new == devx_obj_ops.rxq_obj_new)
 		info->dev_capa |= RTE_ETH_DEV_CAPA_RXQ_SHARE;
diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index f13fc3b353..7e171039eb 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -655,6 +655,14 @@ mlx5_rx_queue_pre_setup(struct rte_eth_dev *dev, uint16_t idx, uint16_t *desc,
 	struct mlx5_rxq_priv *rxq;
 	bool empty;
 
+	if (*desc > 1 << priv->sh->cdev->config.hca_attr.log_max_wq_sz) {
+		DRV_LOG(ERR,
+			"port %u number of descriptors requested for Rx queue"
+			" %u is more than supported",
+			dev->data->port_id, idx);
+		rte_errno = EINVAL;
+		return -EINVAL;
+	}
 	if (!rte_is_power_of_2(*desc)) {
 		*desc = 1 << log2above(*desc);
 		DRV_LOG(WARNING,
diff --git a/drivers/net/mlx5/mlx5_txq.c b/drivers/net/mlx5/mlx5_txq.c
index f05534e168..3e93517323 100644
--- a/drivers/net/mlx5/mlx5_txq.c
+++ b/drivers/net/mlx5/mlx5_txq.c
@@ -333,6 +333,14 @@ mlx5_tx_queue_pre_setup(struct rte_eth_dev *dev, uint16_t idx, uint16_t *desc)
 {
 	struct mlx5_priv *priv = dev->data->dev_private;
 
+	if (*desc > 1 << priv->sh->cdev->config.hca_attr.log_max_wq_sz) {
+		DRV_LOG(ERR,
+			"port %u number of descriptors requested for Tx queue"
+			" %u is more than supported",
+			dev->data->port_id, idx);
+		rte_errno = EINVAL;
+		return -EINVAL;
+	}
 	if (*desc <= MLX5_TX_COMP_THRESH) {
 		DRV_LOG(WARNING,
 			"port %u number of descriptors requested for Tx queue"
-- 
2.45.2