Re: [PATCH v7 2/8] ethdev: add telemetry cmd for registers

[Jie Hai <haijie1@huawei.com>]

Hi, fengchengwen,

Thanks for your review, all will change in next version.

Thanks,
Jie Hai
On 2024/9/14 16:20, fengchengwen wrote:
> On 2024/9/14 15:13, Jie Hai wrote:
>> This patch adds a telemetry command for registers dump,
>> and supports obtaining the registers of a specified module.
>>
>> In one way, the number of registers that can be exported
>> is limited by the number of elements carried by dict and
>> container. In another way, the length of the string
>> exported by telemetry is limited by MAX_OUTPUT_LEN.
>> Therefore, when the number of registers to be exported
>> exceeds, some information will be lost. Warn on the former
>> case.
>>
>> An example usage is shown below:
>> --> /ethdev/regs,0,ring
>> {
>>    "/ethdev/regs": {
>>      "registers_length": 318,
>>      "registers_width": 4,
>>      "register_offset": "0x0",
>>      "version": "0x1140011",
>>      "group_0": {
>>        "Q0_ring_rx_bd_num": "0x0",
>>        "Q0_ring_rx_bd_len": "0x0",
>>        ...
>>        },
>>      "group_1": {
>>          ...
>>      },
>>      ...
>> }
>>
>> Signed-off-by: Jie Hai <haijie1@huawei.com>
>> ---
>>   lib/ethdev/rte_ethdev_telemetry.c | 128 ++++++++++++++++++++++++++++++
>>   1 file changed, 128 insertions(+)
>>
>> diff --git a/lib/ethdev/rte_ethdev_telemetry.c b/lib/ethdev/rte_ethdev_telemetry.c
>> index 6b873e7abe68..1d59c693883e 100644
>> --- a/lib/ethdev/rte_ethdev_telemetry.c
>> +++ b/lib/ethdev/rte_ethdev_telemetry.c
>> @@ -1395,6 +1395,132 @@ eth_dev_handle_port_tm_node_caps(const char *cmd __rte_unused,
>>   	return ret;
>>   }
>>   
>> +static void
>> +eth_dev_add_reg_data(struct rte_tel_data *d, struct rte_dev_reg_info *reg_info,
>> +		     uint32_t idx)
>> +{
>> +	if (reg_info->width == sizeof(uint32_t))
>> +		rte_tel_data_add_dict_uint_hex(d, reg_info->names[idx].name,
>> +			*((uint32_t *)reg_info->data + idx), 0);
>> +	else
>> +		rte_tel_data_add_dict_uint_hex(d, reg_info->names[idx].name,
>> +			*((uint64_t *)reg_info->data + idx), 0);
>> +}
>> +
>> +static int
>> +eth_dev_store_regs(struct rte_tel_data *d, struct rte_dev_reg_info *reg_info)
>> +{
>> +	struct rte_tel_data *groups[RTE_TEL_MAX_DICT_ENTRIES];
>> +	char group_name[RTE_TEL_MAX_STRING_LEN] = {0};
>> +	struct rte_tel_data *group = NULL;
>> +	uint32_t grp_num = 0;
>> +	uint32_t i;
>> +	int ret;
>> +
>> +	rte_tel_data_start_dict(d);
>> +	rte_tel_data_add_dict_uint(d, "register_length", reg_info->length);
>> +	rte_tel_data_add_dict_uint(d, "register_width", reg_info->width);
>> +	rte_tel_data_add_dict_uint_hex(d, "register_offset", reg_info->offset, 0);
>> +	rte_tel_data_add_dict_uint_hex(d, "version", reg_info->version, 0);
>> +
>> +	for (i = 0; i < reg_info->length; i++) {
>> +		if (i % RTE_TEL_MAX_DICT_ENTRIES != 0) {
>> +			eth_dev_add_reg_data(group, reg_info, i);
>> +			continue;
>> +		}
>> +
>> +		group = rte_tel_data_alloc();
>> +		if (group == NULL) {
>> +			ret = -ENOMEM;
>> +			RTE_ETHDEV_LOG_LINE(WARNING, "No enough memory for group data");
>> +			goto out;
>> +		}
>> +		groups[grp_num++] = group;
> 
> Although the probability is very small, the groups array may overflow if the length is very large.
> 
> Suggest add judgement at the begin of this function:
> 
> uint32_t max_cap = (RTE_TEL_MAX_DICT_ENTRIES - 4) * RTE_TEL_MAX_DICT_ENTRIES;   // it will be 65000+ register
> if (reg_info->length > max_cap) {
>      // just output error and exit
> }
> 
>> +		rte_tel_data_start_dict(group);
>> +		eth_dev_add_reg_data(group, reg_info, i);
>> +	}
>> +
>> +	for (i = 0; i < grp_num; i++) {
>> +		snprintf(group_name, RTE_TEL_MAX_STRING_LEN, "group_%u", i);
>> +		ret = rte_tel_data_add_dict_container(d, group_name, groups[i], 0);
>> +		if (ret == -ENOSPC) {
>> +			RTE_ETHDEV_LOG_LINE(WARNING,
>> +				"Reduce register number to be displayed from %u to %u due to limited capacity of telemetry",
>> +				reg_info->length, i * RTE_TEL_MAX_DICT_ENTRIES);
>> +			break;
>> +		}
> 
> It may lead to memory leak when break. If we add such judgement before, there is no need to add such judgement here.
> 
>> +	}
>> +	return 0;
>> +out:
>> +	for (i = 0; i < grp_num; i++)
>> +		rte_tel_data_free(groups[i]);
>> +
>> +	return ret;
>> +}
>> +
>> +static int
>> +eth_dev_get_port_regs(int port_id, struct rte_tel_data *d, char *filter)
>> +{
>> +	struct rte_dev_reg_info reg_info;
>> +	int ret;
>> +
>> +	memset(&reg_info, 0, sizeof(reg_info));
>> +	reg_info.filter = filter;
>> +
>> +	ret = rte_eth_dev_get_reg_info_ext(port_id, &reg_info);
>> +	if (ret != 0) {
>> +		RTE_ETHDEV_LOG_LINE(ERR, "Error getting device reg info: %d", ret);
> 
> how about "Failed to get device reg info, ret = %d"
> 
>> +		return ret;
>> +	}
>> +
>> +	reg_info.data = calloc(reg_info.length, reg_info.width);
>> +	if (reg_info.data == NULL) {
>> +		RTE_ETHDEV_LOG_LINE(ERR, "Fail to allocate memory for reg_info.data");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	reg_info.names = calloc(reg_info.length, sizeof(struct rte_eth_reg_name));
>> +	if (reg_info.names == NULL) {
>> +		RTE_ETHDEV_LOG_LINE(ERR, "Fail to allocate memory for reg_info.names");
>> +		free(reg_info.data);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	ret = rte_eth_dev_get_reg_info_ext(port_id, &reg_info);
>> +	if (ret != 0) {
>> +		RTE_ETHDEV_LOG_LINE(ERR, "Error getting regs from device: %d", ret);
> 
> It seemed the ret is device id, how about "Failed to get device reg info, ret = %d"
> 
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	ret = eth_dev_store_regs(d, &reg_info);
>> +out:
>> +	free(reg_info.data);
>> +	free(reg_info.names);
>> +
>> +	return ret;
>> +}
>> +
>> +static int
>> +eth_dev_handle_port_regs(const char *cmd __rte_unused,
>> +		const char *params,
>> +		struct rte_tel_data *d)
>> +{
>> +	char *filter, *end_param;
>> +	uint16_t port_id;
>> +	int ret;
>> +
>> +	ret = eth_dev_parse_port_params(params, &port_id, &end_param, true);
>> +	if (ret != 0)
>> +		return ret;
>> +
>> +	filter = strtok(end_param, ",");
>> +	if (filter != NULL && strlen(filter) == 0)
>> +		filter = NULL;
>> +
>> +	return eth_dev_get_port_regs(port_id, d, filter);
>> +}
>> +
>>   RTE_INIT(ethdev_init_telemetry)
>>   {
>>   	rte_telemetry_register_cmd("/ethdev/list", eth_dev_handle_port_list,
>> @@ -1436,4 +1562,6 @@ RTE_INIT(ethdev_init_telemetry)
>>   			"Returns TM Level Capabilities info for a port. Parameters: int port_id, int level_id (see tm_capability for the max)");
>>   	rte_telemetry_register_cmd("/ethdev/tm_node_capability", eth_dev_handle_port_tm_node_caps,
>>   			"Returns TM Node Capabilities info for a port. Parameters: int port_id, int node_id (see tm_capability for the max)");
>> +	rte_telemetry_register_cmd("/ethdev/regs", eth_dev_handle_port_regs,
>> +			"Returns all or filtered registers info for a port. Parameters: int port_id, string module_name (Optional if show all)");
>>   }
> 
> .