Re: [Intel-wired-lan] [PATCH iwl-net 3/3] ice: map XDP queues to vectors in ice_vsi_map_rings_to_vectors()

[Jacob Keller <jacob.e.keller@intel.com>]

On 5/16/2024 4:59 AM, Simon Horman wrote:
> On Thu, May 16, 2024 at 01:43:18PM +0200, Larysa Zaremba wrote:
>> On Thu, May 16, 2024 at 09:27:13AM +0100, Simon Horman wrote:
>>> On Wed, May 15, 2024 at 06:02:16PM +0200, Larysa Zaremba wrote:
>>>> ice_pf_dcb_recfg() re-maps queues to vectors with
>>>> ice_vsi_map_rings_to_vectors(), which does not restore the previous
>>>> state for XDP queues. This leads to no AF_XDP traffic after rebuild.
>>>>
>>>> Map XDP queues to vectors in ice_vsi_map_rings_to_vectors().
>>>> Also, move the code around, so XDP queues are mapped independently only
>>>> through .ndo_bpf().
>>>
>>> Hi Larysa,
>>>
>>> I take it the last sentence refers to the placement of ice_map_xdp_rings()
>>> in ice_prepare_xdp_rings() after rather than before the
>>> (cfg_type == ICE_XDP_CFG_PART) condition.
>>>
>>> If so, I see that it is a small change. But I do wonder if it is separate
>>> from fixing the issue described in the first paragraph. And thus would
>>> be better as a separate patch.
>>
>> This is not neccessary for the fix to work, but I think this is intergral to
>> making the change properly. I mean, before the change in the rebuild path we map
>> XDP rings to vectors only once and after the change we do this only once, just
>> previously it was in ice_prepare_xdp_rings() and now it is in
>> ice_vsi_map_rings_to_vectors().
>>
>>>
>>> Also, (I'm raising a separate issue :) breaking out logic into
>>> ice_xdp_ring_from_qid() seems very nice.  But I wonder if this ought to be
>>> part of a cleanup-patch for 'iwl' rather than a fixes patch for 'iwl-next'.
>>>
>>
>> I have separated this into a separate function, because 2 lines exceeded 80 
>> characters, which is not in line with our current style for drivers.
>> And I do not think that this small function creates any more additional 
>> potentian applying problems for this patch. And the change is small enough to 
>> see that the logic stays the same.
>>
>>> OTOH, I do see that breaking out ice_map_xdp_rings() makes sense in the
>>> context of this fix as the same logic is to be called in two places.
>>>
>>> Splitting patches aside, the resulting code looks good to me.
>>>
>>> ...
> 
> Hi Larysa,
> 
> Thanks for your explanation, this all seems reasonable to me.
> 
> Reviewed-by: Simon Horman <horms@kernel.org>
> 

Makes sense to me. With the context that it helps ensure we get the fix
right, we should send it together to net.

Thanks,
Jake