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

TETSURO NAKAMURA nakamura.tetsuro at lab.ntt.co.jp
Thu Aug 3 00:28:39 UTC 2017


Hi Ciara,

Now it's all clear.
It would be great if the patch is applied.

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




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