[PATCH v2 2/7] ethdev: add telemetry cmd for registers

[Jie Hai]

On 2024/2/8 1:03, Ferruh Yigit wrote:
> On 2/5/2024 10:51 AM, Jie Hai wrote:
>> This patch adds a telemetry command for registers dump,
>> and supports get registers with specified names.
>> The length of the string exported by telemetry is limited
>> by MAX_OUTPUT_LEN. Therefore, the filter should be more
>> precise.
>>
>> An example usage is shown below:
>> --> /ethdev/regs,0,INTR
>> {
>>    "/ethdev/regs": {
>>      "registers_length": 318,
>>      "registers_width": 4,
>>      "register_offset": "0x0",
>>      "version": "0x1140011",
>>      "group_0": {
>>        "HNS3_CMDQ_INTR_STS_REG": "0x0",
>>        "HNS3_CMDQ_INTR_EN_REG": "0x2",
>>        "HNS3_CMDQ_INTR_GEN_REG": "0x0",
>>        "queue_0_HNS3_TQP_INTR_CTRL_REG": "0x0",
>>        "queue_0_HNS3_TQP_INTR_GL0_REG": "0xa",
>>        "queue_0_HNS3_TQP_INTR_GL1_REG": "0xa",
>>        "queue_0_HNS3_TQP_INTR_GL2_REG": "0x0",
>>        ...
>>        },
>>      "group_1": {
>>          ...
>>      },
>>      ...
>> }
>>
> 
> What is the intention of 'RTE_TEL_MAX_DICT_ENTRIES' and grouping above?
> 
For a dict in telemetry, the total num of elements is 
RTE_TEL_MAX_DICT_ENTRIES which is 256.
The number of registers may be greater than that.
One option is to seperate the registers in different groups,
each group can be stored in a dict A and can be an entry of another dict B.
RTE_TEL_MAX_DICT_ENTRIES is used so that B has as less as possible 
elements and to make full use of the memory allocated.

>> or as below if the number of registers not exceed the
>> RTE_TEL_MAX_DICT_ENTRIES:
>> --> /ethdev/regs,0,ppp
>> {
>>    "/ethdev/regs": {
>>      "registers_length": 156,
>>      "registers_width": 4,
>>      "register_offset": "0x0",
>>      "version": "0x1140011",
>>      "ppp_key_drop_num": "0x0",
>>      "ppp_rlt_drop_num": "0x0",
>>      "ssu_ppp_mac_key_num_l": "0x1",
>>      "ssu_ppp_mac_key_num_h": "0x0",
>>      "ssu_ppp_host_key_num_l": "0x1",
>>      "ssu_ppp_host_key_num_h": "0x0",
>>      "ppp_ssu_mac_rlt_num_l": "0x1",
>>          ...
>>     }
>> }
>>
>> Signed-off-by: Jie Hai <haijie1 at huawei.com>
> 
> .