Re: [PATCH v4 1/7] ethdev: support report register names and filter

[fengchengwen <fengchengwen@huawei.com>]

Hi Jie,

On 2024/2/26 11:07, Jie Hai wrote:
> This patch adds "filter" and "names" fields to "rte_dev_reg_info"
> structure. Names of registers in data fields can be reported and
> the registers can be filtered by their names.
> 
> The new API rte_eth_dev_get_reg_info_ext() is added to support
> reporting names and filtering by names. And the original API
> rte_eth_dev_get_reg_info() does not use the name and filter fields.
> A local variable is used in rte_eth_dev_get_reg_info for
> compatibility. If the drivers does not report the names, set them
> to "offset_XXX".
> 
> Signed-off-by: Jie Hai <haijie1@huawei.com>
> ---
>  doc/guides/rel_notes/release_24_03.rst |  8 ++++++
>  lib/ethdev/rte_dev_info.h              | 11 +++++++++
>  lib/ethdev/rte_ethdev.c                | 34 ++++++++++++++++++++++++++
>  lib/ethdev/rte_ethdev.h                | 28 +++++++++++++++++++++
>  lib/ethdev/version.map                 |  1 +
>  5 files changed, 82 insertions(+)
> 
> diff --git a/doc/guides/rel_notes/release_24_03.rst b/doc/guides/rel_notes/release_24_03.rst
> index 32d0ad8cf6a7..fa46da427dca 100644
> --- a/doc/guides/rel_notes/release_24_03.rst
> +++ b/doc/guides/rel_notes/release_24_03.rst
> @@ -132,6 +132,11 @@ New Features
>      to support TLS v1.2, TLS v1.3 and DTLS v1.2.
>    * Added PMD API to allow raw submission of instructions to CPT.
>  
> +  * **Added support for dumping registers with names and filter.**
> +
> +    * Added new API functions ``rte_eth_dev_get_reg_info_ext()`` to and filter
> +      the registers by their names and get the information of registers(names,
> +      values and other attributes).
>  
>  Removed Items
>  -------------
> @@ -197,6 +202,9 @@ ABI Changes
>  
>  * No ABI change that would break compatibility with 23.11.
>  
> +* ethdev: Added ``filter`` and ``names`` fields to ``rte_dev_reg_info``
> +  structure for reporting names of registers and filtering them by names.
> +
>  
>  Known Issues
>  ------------
> diff --git a/lib/ethdev/rte_dev_info.h b/lib/ethdev/rte_dev_info.h
> index 67cf0ae52668..0ad4a43b9526 100644
> --- a/lib/ethdev/rte_dev_info.h
> +++ b/lib/ethdev/rte_dev_info.h
> @@ -11,6 +11,11 @@ extern "C" {
>  
>  #include <stdint.h>
>  
> +#define RTE_ETH_REG_NAME_SIZE 128

Almost all stats name size is 64, why not keep consistent?

> +struct rte_eth_reg_name {
> +	char name[RTE_ETH_REG_NAME_SIZE];
> +};
> +
>  /*
>   * Placeholder for accessing device registers
>   */
> @@ -20,6 +25,12 @@ struct rte_dev_reg_info {
>  	uint32_t length; /**< Number of registers to fetch */
>  	uint32_t width; /**< Size of device register */
>  	uint32_t version; /**< Device version */
> +	/**
> +	 * Filter for target subset of registers.
> +	 * This field could affects register selection for data/length/names.
> +	 */
> +	const char *filter;
> +	struct rte_eth_reg_name *names; /**< Registers name saver */
>  };
>  
>  /*
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index f1c658f49e80..9ef50c633ce3 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -6388,8 +6388,37 @@ rte_eth_read_clock(uint16_t port_id, uint64_t *clock)
>  
>  int
>  rte_eth_dev_get_reg_info(uint16_t port_id, struct rte_dev_reg_info *info)
> +{
> +	struct rte_dev_reg_info reg_info = { 0 };
> +	int ret;
> +
> +	if (info == NULL) {
> +		RTE_ETHDEV_LOG_LINE(ERR,
> +			"Cannot get ethdev port %u register info to NULL",
> +			port_id);
> +		return -EINVAL;
> +	}
> +
> +	reg_info.length = info->length;
> +	reg_info.data = info->data;
> +
> +	ret = rte_eth_dev_get_reg_info_ext(port_id, &reg_info);
> +	if (ret != 0)
> +		return ret;
> +
> +	info->length = reg_info.length;
> +	info->width = reg_info.width;
> +	info->version = reg_info.version;
> +	info->offset = reg_info.offset;
> +
> +	return 0;
> +}
> +
> +int
> +rte_eth_dev_get_reg_info_ext(uint16_t port_id, struct rte_dev_reg_info *info)
>  {
>  	struct rte_eth_dev *dev;
> +	uint32_t i;
>  	int ret;
>  
>  	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
> @@ -6408,6 +6437,11 @@ rte_eth_dev_get_reg_info(uint16_t port_id, struct rte_dev_reg_info *info)
>  
>  	rte_ethdev_trace_get_reg_info(port_id, info, ret);
>  
> +	/* Report the default names if drivers not report. */
> +	if (info->names != NULL && strlen(info->names[0].name) == 0)
> +		for (i = 0; i < info->length; i++)
> +			snprintf(info->names[i].name, RTE_ETH_REG_NAME_SIZE,
> +				"offset_%x", info->offset + i * info->width);

%x has no prefix "0x", may lead to confused.
How about use %u ?

Another question, if app don't zero names' memory, then its value is random, so it will not enter this logic.
Suggest memset item[0]'s name memory before invoke PMD ops.

>  	return ret;
>  }
>  
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index ed27360447a3..09e2d5fdb49b 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -5066,6 +5066,34 @@ __rte_experimental
>  int rte_eth_get_monitor_addr(uint16_t port_id, uint16_t queue_id,
>  		struct rte_power_monitor_cond *pmc);
>  
> +/**
> + * Retrieve the filtered device registers (values and names) and
> + * register attributes (number of registers and register size)
> + *
> + * @param port_id
> + *   The port identifier of the Ethernet device.
> + * @param info
> + *   Pointer to rte_dev_reg_info structure to fill in.
> + *   If info->filter is not NULL and the driver does not support names or
> + *   filter, return error. If info->filter is NULL, return info for all
> + *   registers (seen as filter none).
> + *   If info->data is NULL, the function fills in the width and length fields.
> + *   If non-NULL, ethdev considers there are enough spaces to store the
> + *   registers, and the values of registers whose name contains the filter
> + *   string are put into the buffer pointed at by the data field. Do the same
> + *   for the names of registers if info->names is not NULL. If drivers do not
> + *   report names, default names are given by ethdev.

It's a little hard to understand. Suggest use '-' for each field, just like rte_eth_remove_tx_callback

> + * @return
> + *   - (0) if successful.
> + *   - (-ENOTSUP) if hardware doesn't support.
> + *   - (-EINVAL) if bad parameter.
> + *   - (-ENODEV) if *port_id* invalid.
> + *   - (-EIO) if device is removed.
> + *   - others depends on the specific operations implementation.
> + */
> +__rte_experimental
> +int rte_eth_dev_get_reg_info_ext(uint16_t port_id, struct rte_dev_reg_info *info);
> +
>  /**
>   * Retrieve device registers and register attributes (number of registers and
>   * register size)
> diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
> index 17e4eac8a4cc..c41a64e404db 100644
> --- a/lib/ethdev/version.map
> +++ b/lib/ethdev/version.map
> @@ -325,6 +325,7 @@ EXPERIMENTAL {
>  	rte_flow_template_table_resizable;
>  	rte_flow_template_table_resize;
>  	rte_flow_template_table_resize_complete;
> +	rte_eth_dev_get_reg_info_ext;

should place with alphabetical order.

Thanks

>  };
>  
>  INTERNAL {
>