From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Wang <jasowang@redhat.com>
Subject: Re: [RFC 0/7] PMD driver for AF_XDP
Date: Thu, 1 Mar 2018 21:18:01 +0800
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Cc: "Karlsson, Magnus" <magnus.karlsson@intel.com>,
 "Topel, Bjorn" <bjorn.topel@intel.com>, "dev@dpdk.org" <dev@dpdk.org>
To: "Zhang, Qi Z" <qi.z.zhang@intel.com>
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On 2018年03月01日 20:56, Zhang, Qi Z wrote:
>>>>>> BTW, performance test shows our PMD can reach 94%~98% of the
>>>>>> orignal benchmark when share memory is enabled.
>>>>> Hi:
>>>>>
>>>>> Looks like zero copy is not used in this series. Any plan to support that?
>>>> Zero copy is enabled in patch 5, if a mempool passed check_mempool,
>>>> it will be registered to af_xdp socket.
>>>> so there will be no memcpy between mbuf and af_xdp.
>> Aha, I see. So the zerocopy was limited to some specific use case. And if I
>> understand it correctly, zc mode could not be used for VM.
> I think except the limitation for mempool layout, zerocopy is transparent to DPDK application, only difference is performance.
> Sorry, I may not get your point, if you could explain more about the VM usage.
>
> Regards
> Qi

No problem, so the question is:

Can zerocopy be used when using testpmd to foward packets between 
vhost-user and AF_XDP socket?

Thanks