Re: [dpdk-dev] [PATCH v3] ethdev: support QinQ strip dynamic configuration

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

On 7/1/2019 11:07 AM, Andrew Rybchenko wrote:
> On 27.06.2019 14:08, Ferruh Yigit wrote:
>> On 4/19/2019 6:59 AM, viveksharma@marvell.com wrote:
>>> From: Vivek Sharma <viveksharma@marvell.com>
>>>
>>> Enable missing support for runtime configuration (setting/getting)
>>> of QinQ strip rx offload for a given ethdev.
>>>
>>> Signed-off-by: Vivek Sharma <viveksharma@marvell.com>
>> <...>
>>
>>> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
>>> index 40a068f..c1792f4 100644
>>> --- a/lib/librte_ethdev/rte_ethdev.h
>>> +++ b/lib/librte_ethdev/rte_ethdev.h
>>> @@ -550,11 +550,13 @@ struct rte_eth_rss_conf {
>>>   #define ETH_VLAN_STRIP_OFFLOAD   0x0001 /**< VLAN Strip  On/Off */
>>>   #define ETH_VLAN_FILTER_OFFLOAD  0x0002 /**< VLAN Filter On/Off */
>>>   #define ETH_VLAN_EXTEND_OFFLOAD  0x0004 /**< VLAN Extend On/Off */
>>> +#define ETH_QINQ_STRIP_OFFLOAD   0x0008 /**< QINQ Strip On/Off */
>>>   
>>>   /* Definitions used for mask VLAN setting */
>>>   #define ETH_VLAN_STRIP_MASK   0x0001 /**< VLAN Strip  setting mask */
>>>   #define ETH_VLAN_FILTER_MASK  0x0002 /**< VLAN Filter  setting mask*/
>>>   #define ETH_VLAN_EXTEND_MASK  0x0004 /**< VLAN Extend  setting mask*/
>>> +#define ETH_QINQ_STRIP_MASK   0x0008 /**< QINQ Strip  setting mask */
>>>   #define ETH_VLAN_ID_MAX       0x0FFF /**< VLAN ID is in lower 12 bits*/
>> On its own patch looks ok but a few high level questions:
>>
>> 1- Why we need this interim defines, instead of using actual offload values?
>> Although changing this will be API/ABI breakage.
>>
>> 2- Why we have specific function to set vlan offloads, for other offloads the
>> way is stop device and reconfigure it with new offload flags.
>>
>> 3- If devices can change offload configuration dynamically, do we need a generic
>> API to alter the offload configs? (similar to these vlan APIs but more generic)?
> 
> If dynamic switching of offloads is really required, I think it would be
> good if it is unified. If so, we can deprecate
> rte_eth_dev_{s,g}et_vlan_offload() and implement it using the new one
> to remove the old one from driver interface at least.
> It requires reporting of dynamically switchable offloads on device and
> queue level. Or just dynamically switchable offloads in assumption that
> if the offload is supported on queue level and dynamically switchable,
> it is dynamically switchable on queue level.

Not sure if "dynamic switching of offloads" required, but I agree we may need to
add "dynamically switchable offload" reporting for that.

> 
>> Related to the patch, what do you think about following options:
>> a)
>> - Get this patch
>> - Send a deprecation notice for 1) in this release
>> - Next release remove these flags, which will be practically reverse this patch
>> and more
>>
>> b)
>> - Send a deprecation notice for 1) in this release
>> - Next release update the APIs and a smaller/different version of this patch
>> will be required.
> 
> I'm OK with both options, but I think it would be fair to go (a) to avoid
> postponing of the feature too long.

OK

> 
> The patch itself should update rte_eth_dev_{s,g}et_vlan_offload()
> descriptions which enumerate switchable offloads.

+1

@Vivek, can you please send a new version with this update?