[ovs-discuss] How to enable zero-copy feature of vhost-user ??

TETSURO NAKAMURA nakamura.tetsuro at lab.ntt.co.jp
Tue Aug 29 09:40:32 UTC 2017


On 2017/08/25 20:22, Loftus, Ciara wrote:
>> Hi Ciara,
>>
>> Now it's all clear.
>> It would be great if the patch is applied.
> 
> Hi Tetsuro,
> 
> I submitted a patch that enables the zero copy feature during runtime, if you are interested:
> https://patchwork.ozlabs.org/patch/805844/
> https://patchwork.ozlabs.org/patch/805845/
> 
> If you try it out, let me know how you get on.
> 
> Thanks,
> Ciara

Hi Ciara,

Thank you for informing me.
I will try it out later.

Thanks,
Tetsuro.

> 
>>
>> Thank you,
>>
>> Tetsuro
>>
>> On 2017/08/02 18:12, Loftus, Ciara wrote:
>>>>
>>>> Hi Ciara,
>>>>
>>>> Thank you for the infomation.
>>>> IIUC, you should compile ovs again to use zero copy feature so far, right ?
>>>
>>> Hi Tetsuro,
>>>
>>> That's right. I might look into creating a patch to enable it during runtime.
>> But for now, you need to apply the patch below & recompile.
>>>
>>> Thanks,
>>> Ciara
>>>
>>>>
>>>> On 2017/08/02 17:04, Loftus, Ciara wrote:
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> I heard that, about vhost-user interface,
>>>>>> 0 copy rx is under development,
>>>>>> but 0 copy tx from a vm is already supported with both vhost-user and
>>>>>> ovs-dpdk.
>>>>>>
>>>>>> However, I couldn't find out how to enable that zero copy feature from
>>>>>> the ovs document (/ovs/Documentation/topics/dpdk/vhost-user.rst)
>>>>>>
>>>>>> Could you inform me how to enable it or where I should refer about
>> the
>>>>>> feature ?
>>>>>
>>>>> Try this:
>>>>>
>>>>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
>>>>> index ea17b97..9fdae46 100644
>>>>> --- a/lib/netdev-dpdk.c
>>>>> +++ b/lib/netdev-dpdk.c
>>>>> @@ -944,6 +944,7 @@ netdev_dpdk_vhost_construct(struct netdev
>>>> *netdev)
>>>>>                  dpdk_get_vhost_sock_dir(), name);
>>>>>
>>>>>         dev->vhost_driver_flags &= ~RTE_VHOST_USER_CLIENT;
>>>>> +    dev->vhost_driver_flags |=
>> RTE_VHOST_USER_DEQUEUE_ZERO_COPY;
>>>>>         err = rte_vhost_driver_register(dev->vhost_id, dev-
>>>>> vhost_driver_flags);
>>>>>         if (err) {
>>>>>             VLOG_ERR("vhost-user socket device setup failure for socket
>> %s\n",
>>>>>
>>>>> Thanks,
>>>>> Ciara
>>>>>
>>>>>>
>>>>>> Thanks
>>>>>>
>>>>>> --
>>>>>> Tetsuro Nakamura
>>>>>>
>>>>>> _______________________________________________
>>>>>> discuss mailing list
>>>>>> discuss at openvswitch.org
>>>>>> https://mail.openvswitch.org/mailman/listinfo/ovs-discuss
>>>>>
>>>>>
>>>>
>>>> --
>>>> Tetsuro Nakamura <nakamura.tetsuro at lab.ntt.co.jp>
>>>> NTT Network Service Systems Laboratories
>>>> TEL:0422 59 6914(National)/+81 422 59 6914(International)
>>>> 3-9-11, Midori-Cho Musashino-Shi, Tokyo 180-8585 Japan
>>>>
>>>
>>
>> --
>> Tetsuro Nakamura <nakamura.tetsuro at lab.ntt.co.jp>
>> NTT Network Service Systems Laboratories
>> TEL:0422 59 6914(National)/+81 422 59 6914(International)
>> 3-9-11, Midori-Cho Musashino-Shi, Tokyo 180-8585 Japan
>>
> 

-- 
Tetsuro Nakamura <nakamura.tetsuro at lab.ntt.co.jp>
NTT Network Service Systems Laboratories
TEL:0422 59 6914(National)/+81 422 59 6914(International)
3-9-11, Midori-Cho Musashino-Shi, Tokyo 180-8585 Japan




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