Re: [PATCH v3] ethdev: introduce dump API

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 2/9/2022 1:21 AM, Min Hu (Connor) wrote:
> Added the ethdev dump API which provides querying private info from ethdev.
> There exists many private properties in different PMD drivers, such as
> adapter state, Rx/Tx func algorithm in hns3 PMD. The information of these
> properties is important for debug. As the information is private, the new
> API is introduced.
> 
> Signed-off-by: Min Hu (Connor) <humin29@huawei.com>
> Acked-by: Morten Brørup <mb@smartsharesystems.com>
> Acked-by: Ray Kinsella <mdr@ashroe.eu>
> Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
> ---
> v3:
> * change 'ethdev' to 'device'
> v2:
> * fixed comments from Ferruh.
> ---
>   doc/guides/rel_notes/release_22_03.rst |  7 +++++++
>   lib/ethdev/ethdev_driver.h             | 23 +++++++++++++++++++++++
>   lib/ethdev/rte_ethdev.c                | 17 +++++++++++++++++
>   lib/ethdev/rte_ethdev.h                | 20 ++++++++++++++++++++
>   lib/ethdev/version.map                 |  3 +++
>   5 files changed, 70 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
> index b20716c521..0e3d3ae365 100644
> --- a/doc/guides/rel_notes/release_22_03.rst
> +++ b/doc/guides/rel_notes/release_22_03.rst
> @@ -64,6 +64,13 @@ New Features
>       - ``rte_ipv6_udptcp_cksum_mbuf()``
>       - ``rte_ipv6_udptcp_cksum_mbuf_verify()``
>   
> +* **Added the private dump API, for query private info from device.**
> +
> +  Added the private dump API which provides querying private info from device.
> +  There exists many private properties in different PMD drivers. The
> +  information of these properties is important for debug. As the information
> +  is private, the new API is introduced.
> +
>   * **Updated AF_XDP PMD**
>   
>     * Added support for libxdp >=v1.2.2.
> diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
> index 7d27781f7d..a0bd066ab3 100644
> --- a/lib/ethdev/ethdev_driver.h
> +++ b/lib/ethdev/ethdev_driver.h
> @@ -990,6 +990,26 @@ typedef int (*eth_representor_info_get_t)(struct rte_eth_dev *dev,
>   typedef int (*eth_rx_metadata_negotiate_t)(struct rte_eth_dev *dev,
>   				       uint64_t *features);
>   
> +/**
> + * @internal
> + * Dump private info from device to a file.
> + *
> + * @param dev
> + *   Port (ethdev) handle.
> + * @param file
> + *   A pointer to a file for output.
> + *
> + * @retval 0
> + *   Success
> + * @retval -EINVAL
> + *   Invalid file
> + * @retval -ENOTSUP
> + *   Not supported
> + * @retval -ENODEV
> + *   Invalid port_id

For dev_ops (eth_dev_priv_dump_t), I don't think '-ENOTSUP' and '-ENODEV'
are valid errors, those cases covered by API before dev_ops called.

Also '@return' is missing.

What about below:
   *
   * @return
   *   Negative value on error, 0 on success.
   *
   * @retval 0
   *   Success
   * @retval -EINVAL
   *   Invalid file
   */

> + */
> +typedef int (*eth_dev_priv_dump_t)(struct rte_eth_dev *dev, FILE *file);
> +
>   /**
>    * @internal A structure containing the functions exported by an Ethernet driver.
>    */
> @@ -1186,6 +1206,9 @@ struct eth_dev_ops {
>   	 * kinds of metadata to the PMD
>   	 */
>   	eth_rx_metadata_negotiate_t rx_metadata_negotiate;
> +
> +	/** Dump private info from device */
> +	eth_dev_priv_dump_t eth_dev_priv_dump;
>   };
>   
>   /**
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index 917a320afa..5ee316a3c0 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -6485,6 +6485,23 @@ rte_eth_rx_metadata_negotiate(uint16_t port_id, uint64_t *features)
>   		       (*dev->dev_ops->rx_metadata_negotiate)(dev, features));
>   }
>   
> +int
> +rte_eth_dev_priv_dump(uint16_t port_id, FILE *file)
> +{
> +	struct rte_eth_dev *dev;
> +
> +	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> +	dev = &rte_eth_devices[port_id];
> +
> +	if (file == NULL) {
> +		RTE_ETHDEV_LOG(ERR, "Invalid file (NULL)\n");
> +		return -EINVAL;
> +	}
> +
> +	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->eth_dev_priv_dump, -ENOTSUP);
> +	return eth_err(port_id, (*dev->dev_ops->eth_dev_priv_dump)(dev, file));
> +}
> +

Can you please move the function up in the file?
Bottom of the file is for static inline functions, APIs are above the
"#include <rte_ethdev_core.h>" line, can you move the function above
that?

>   RTE_LOG_REGISTER_DEFAULT(rte_eth_dev_logtype, INFO);
>   
>   RTE_INIT(ethdev_init_telemetry)
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index 147cc1ced3..e6ea294402 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -5902,6 +5902,26 @@ rte_eth_tx_buffer(uint16_t port_id, uint16_t queue_id,
>   	return rte_eth_tx_buffer_flush(port_id, queue_id, buffer);
>   }
>   
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
> + *
> + * Dump private info from device to a file. Provided data and the order depends
> + * on the PMD.
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param file
> + *   A pointer to a file for output.
> + * @return
> + *   - (-ENODEV) if *port_id* is invalid.
> + *   - (-EINVAL) if null file.
> + *   - (-ENOTSUP) if the device does not support this function.
> + *   - (0) on success

Can you please list "(0) on success" to be consistent with (most :( of the) other comments?

Also need to add "(-EIO) if device is removed." too, which can be
returned by 'eth_err()'.


> + */
> +__rte_experimental
> +int rte_eth_dev_priv_dump(uint16_t port_id, FILE *file);
> +
>   #ifdef __cplusplus
>   }
>   #endif
> diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
> index 1f7359c846..376ea139aa 100644
> --- a/lib/ethdev/version.map
> +++ b/lib/ethdev/version.map
> @@ -256,6 +256,9 @@ EXPERIMENTAL {
>   	rte_flow_flex_item_create;
>   	rte_flow_flex_item_release;
>   	rte_flow_pick_transfer_proxy;
> +
> +	# added in 22.03
> +	rte_eth_dev_priv_dump;

next version needs to be rebased on top of next-net, because of other
APIs merged, fyi

>   };
>   
>   INTERNAL {