Re: [PATCH] ethdev: add dump regs for telemetry

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

On 12/14/2023 1:56 AM, Jie Hai wrote:
> The ethdev library now registers a telemetry command for
> dump regs.
> 
> An example usage is shown below:
> --> /ethdev/regs,test
> {
>   "/ethdev/regs": {
>     "regs_offset": 0,
>     "regs_length": 3192,
>     "regs_width": 4,
>     "device_version": "0x1080f00",
>     "regs_file": "port_0_regs_test"
>   }
> }
> 
> Signed-off-by: Jie Hai <haijie1@huawei.com>
> ---
>  lib/ethdev/rte_ethdev_telemetry.c | 93 +++++++++++++++++++++++++++++++
>  1 file changed, 93 insertions(+)
> 
> diff --git a/lib/ethdev/rte_ethdev_telemetry.c b/lib/ethdev/rte_ethdev_telemetry.c
> index b01028ce9b60..33ec4739aa9b 100644
> --- a/lib/ethdev/rte_ethdev_telemetry.c
> +++ b/lib/ethdev/rte_ethdev_telemetry.c
> @@ -5,6 +5,7 @@
>  #include <ctype.h>
>  #include <stdlib.h>
>  
> +#include <rte_malloc.h>
>  #include <rte_kvargs.h>
>  #include <rte_telemetry.h>
>  
> @@ -1395,6 +1396,96 @@ eth_dev_handle_port_tm_node_caps(const char *cmd __rte_unused,
>  	return ret;
>  }
>  
> +static int
> +eth_dev_get_port_regs(uint16_t port_id, struct rte_dev_reg_info *reg_info,
> +		      const char *file_name)
> +{
> +	uint64_t buf_size;
> +	size_t nr_written;
> +	void *data;
> +	FILE *fp;
> +	int ret;
> +
> +	ret = rte_eth_dev_get_reg_info(port_id, reg_info);
> +	if (ret != 0) {
> +		RTE_ETHDEV_LOG(ERR,
> +			"Error getting device reg info: %d\n", ret);
> +		return ret;
> +	}
> +
> +	buf_size = reg_info->length * reg_info->width;
> +	data = rte_zmalloc(NULL, buf_size, 0);
> +	if (!data) {
> +		RTE_ETHDEV_LOG(ERR,
> +			"Error allocating %zu bytes buffer\n", buf_size);
> +		return -ENOMEM;
> +	}
> +
> +	reg_info->data = data;
> +	ret = rte_eth_dev_get_reg_info(port_id, reg_info);
> +	if (ret != 0) {
> +		RTE_ETHDEV_LOG(ERR,
> +			"Error getting regs from device: %d\n", ret);
> +		goto out;
> +	}
> +
> +	fp = fopen(file_name, "wb");
> +	if (fp == NULL) {
> +		printf("Error during opening '%s' for writing: %s\n",
> +			file_name, strerror(errno));
> +		ret = -EINVAL;
> +	} else {
> +		nr_written = fwrite(reg_info->data, 1, buf_size, fp);
>

Above code writes register data to a file.

I am not sure about this kind of usage of telemetry command, that it
cause data to be written to a file.

My understanding is, telemetry usage is based on what telemetry client
receives.
What do you think just keep the 'reg_info' fields excluding data to the
file?