Re: [dpdk-dev] [PATCH 0/3] virtio_user as an alternative exception path

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2016-12-02 14:31, Jianfeng Tan:
> In v16.07, we upstreamed a virtual device, virtio_user (with vhost-user
> as the backend). The path to go with a vhost-kernel backend has been
> dropped for bad performance comparing to vhost-user and code simplicity.
> 
> But after a second thought, virtio_user + vhost-kernel is a good 
> candidate as an exceptional path, such as KNI, which exchanges packets
> with kernel networking stack.
>   - maintenance: vhost-net (kernel) is upstreamed and extensively used 
>     kernel module. We don't need any out-of-tree module like KNI.
>   - performance: as with KNI, this solution would use one or more
>     kthreads to send/receive packets from user space DPDK applications,
>     which has little impact on user space polling thread (except that
>     it might enter into kernel space to wake up those kthreads if
>     necessary.
>   - features: vhost-net is born to be a networking solution, which has
>     lots of networking related featuers, like multi queue, tso, multi-seg
>     mbuf, etc.

That's a really interesting trial.
Have I already said that I don't like KNI? ;)

> Known issues for current version:
>   - Multiqueue not supported yet.
>   - Offloading is completely enabled yet; to enhance, we will translate

Is a "not" missing in this sentence?

>     the virtio header info into mbuf metadata when receiving packets
>     from kernel; and translate mbuf metadata info into virtio header
>     when sending packets to kernel.

So what is the ambition for 17.02?
Do you think it could be integrated?