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

[Slava Ovsiienko]

Thank you for the patch.
Acked-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>

> -----Original Message-----
> From: Igor Gutorov <igootorov at gmail.com>
> Sent: Wednesday, August 7, 2024 11:44 PM
> To: dev at dpdk.org
> Cc: Igor Gutorov <igootorov at gmail.com>; stable at dpdk.org
> Subject: [PATCH v3 1/2] net/mlx5: fix reported Rx/Tx desc limits
> 
> 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 at dpdk.org
> 
> Signed-off-by: Igor Gutorov <igootorov at 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