Re: [Qemu-devel] [PATCH v11 12/12] netfilter: add multiqueue support

[Yang Hongyang <yanghy@cn.fujitsu.com>]

On 09/22/2015 05:30 PM, Jason Wang wrote:
[...]
>>>>>>
>>>>>>         if (!nf->netdev_id) {
>>>>>>             error_setg(errp, "Parameter 'netdev' is required");
>>>>>> @@ -165,9 +174,6 @@ static void netfilter_complete(UserCreatable
>>>>>> *uc, Error **errp)
>>>>>>             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "netdev",
>>>>>>                        "a network backend id");
>>>>>>             return;
>>>>>> -    } else if (queues > 1) {
>>>>>> -        error_setg(errp, "Multi queue is not supported");
>>>>>> -        return;
>>>>>>         }
>>>>>>
>>>>>>         if (get_vhost_net(ncs[0])) {
>>>>>> @@ -187,6 +193,17 @@ static void netfilter_complete(UserCreatable
>>>>>> *uc, Error **errp)
>>>>>>         }
>>>>>>         QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
>>>>>>
>>>>>> +    if (queues > 1) {
>>>>>> +        /*
>>>>>> +         * Store the properties of the filter except "type"
>>>>>> property.
>>>>>> +         * When there's multiqueue, we will create a new filter
>>>>>> object
>>>>>> +         * of the same type and same properties. this hashtable is
>>>>>> used
>>>>>> +         * to set newly created object properties.
>>>>>> +         */
>>>>>> +        proptable = g_hash_table_new_full(NULL, NULL, NULL,
>>>>>> +                                          proptb_free_val_func);
>>>>>> +    }
>>>>>
>>>>> I'm thinking whether or not duplicate all the properties in each
>>>>> netfilters is a good method. Maybe we can have a another ojbect with
>>>>> array of pointers to NetFilter objects embedded? Another question is
>>>>> whether or not we need to do this at this level. Maybe we can make the
>>>>> necessary Netfilter multiqueue aware. E.g let buffer filter to have
>>>>> multiqueue also? Then you may only need a single timer?
>>>>
>>>> Sorry I don't get it at first. I also thought about make the buffer
>>>> filter to
>>>> have multiqueue, but there comes problem, how to distinguish which
>>>> queue
>>>> we should go in when receive the packet, we need to add a mechanism to
>>>> distinguish which queue belongs to which net client's queue, that will
>>>> be more complex, while current multiqueue implementation of net clients
>>>> is multiple net clients with the same name, current solution is the
>>>> simplest
>>>> solution I can think of...
>>>
>>> I'm not sure I get this. But there's a queue_index filed in each
>>> NetClientState which may help in this case.
>>
>> Ah, I see, thank you. There's another reason I do this in filter abstract
>> layer is that the concrete filter implementation do not need to deal
>> with the
>> multiqueue, will simplify the filter implement a lot, otherwise, every
>> filter need to implement it's own multiqueue support.
>
> Probably not, just pointing all queues to a single netfilter object may
> be sufficient (e.g for dump). And it's much easier for some kind of
> filter (e.g traffic throttling) if it was multiqueue aware.

I see, will think about doing this other way, thank you!

>
> .
>

-- 
Thanks,
Yang.