Re: [PATCH net-next v2 5/6] devlink: Adding num MSI-X vectors per VF NVRAM config param

[Florian Fainelli <f.fainelli@gmail.com>]

On 10/19/2017 02:43 PM, Jiri Pirko wrote:
> Thu, Oct 19, 2017 at 11:39:55PM CEST, jiri@resnulli.us wrote:
>> Thu, Oct 19, 2017 at 10:32:21PM CEST, yuvalm@mellanox.com wrote:
>>>> Adding DEVLINK_PERM_CONFIG_MSIX_VECTORS_PER_VF permanent
>>>> config
>>>> parameter.  Defines number of MSI-X vectors allocated per VF.
>>>> Value is permanent (stored in NVRAM), so becomes the new default
>>>> value for this device.
>>>
>>> Sounds like you're having this enforce the same configuration for all child VFs.
>>
>> Yeah, this sounds like per-port config.
> 
> This opens old but lately silent discussion about introducing new port
> types for different things. Like VF, dsa CPU port or dsa inter-chip
> ports.

FWIW, the "issue" with representing VF, DSA CPU port or DSA inter-chip
port is that you would be representing a pipe, so there is obviously a
question of whether your represent one end or both ends of that pipe,
and how do you make sure both stay in sync if you represent those.

For instance, for an inter-switch connection, I could decide to
configure VLANs 1-3 tagged on one end of the connection, and forget to
that on the other end of the connection, and that's just one example
where things can go seriously wrong.

> 
>>
>>
>>>
>>>>
>>>> Signed-off-by: Steve Lin <steven.lin1@broadcom.com>
>>>> Acked-by: Andy Gospodarek <gospo@broadcom.com>
>>>> ---
>>>>  include/uapi/linux/devlink.h | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
>>>> index 8ad6c63..ef163b6 100644
>>>> --- a/include/uapi/linux/devlink.h
>>>> +++ b/include/uapi/linux/devlink.h
>>>> @@ -260,6 +260,7 @@ enum devlink_perm_config_param {
>>>>  	DEVLINK_PERM_CONFIG_SRIOV_ENABLED,
>>>>  	DEVLINK_PERM_CONFIG_NUM_VF_PER_PF,
>>>>  	DEVLINK_PERM_CONFIG_MAX_NUM_PF_MSIX_VECT,
>>>> +	DEVLINK_PERM_CONFIG_MSIX_VECTORS_PER_VF,
>>>>  };
>>>>
>>>>  #endif /* _UAPI_LINUX_DEVLINK_H_ */
>>>> --
>>>> 2.7.4
>>>


-- 
Florian