Re: [PATCH net-next RFC 02/13] devlink: Add reload levels data to dev get

[Moshe Shemesh <moshe@mellanox.com>]

On 7/28/2020 3:58 AM, Jakub Kicinski wrote:
> On Mon, 27 Jul 2020 14:02:22 +0300 Moshe Shemesh wrote:
>> Expose devlink reload supported levels and driver's default level to the
>> user through devlink dev get command.
>>
>> Examples:
>> $ devlink dev show
>> pci/0000:82:00.0:
>>    reload_levels_info:
>>      default_level driver
>>      supported_levels:
>>        driver fw_reset fw_live_patch
>> pci/0000:82:00.1:
>>    reload_levels_info:
>>      default_level driver
>>      supported_levels:
>>        driver fw_reset fw_live_patch
>>
>> $ devlink dev show -jp
>> {
>>      "dev": {
>>          "pci/0000:82:00.0": {
>>              "reload_levels_info": {
>>                  "default_level": "driver",
>>                  "supported_levels": [ "driver","fw_reset","fw_live_patch" ]
>>              }
>>          },
>>          "pci/0000:82:00.1": {
>>              "reload_levels_info": {
>>                  "default_level": "driver",
>>                  "supported_levels": [ "driver","fw_reset","fw_live_patch" ]
>>              }
>>          }
>>      }
>> }
>>
>> Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
> The fact that the driver supports fw_live_patch, does not necessarily
> mean that the currently running FW can be live upgraded to the
> currently flashed one, right?


That's correct, though the feature is supported, the firmware gap may 
not be suitable for live_patch.

The user will be noted accordingly by extack message.

>
> This interface does not appear to be optimal for the purpose.
>
> Again, documentation of what can be lost (in terms of configuration and
> features) upon upgrade is missing.


I will clarify in documentation. On live_patch nothing should be lost or 
re-initialized, that's the "live" thing.