[dpdk-dev] KNI discussion in userspace event

[Ferruh Yigit <ferruh.yigit@intel.com>]

Hi,

There was an "Interworking with the Linux Kernel" discussion in the DPDK
userspace event, this mail is to summarize the output and to get more
comments from community.


Briefly, KNI mostly will stay as it is as an interworking with the Linux
kernel solution.
Out of tree kernel module concern is still there, but there is no clear
alternative to switch. And community still care about performance of KNI
and control path of KNI. Only KNI VHOST may go away. KNI PMD depends on
community interest. There was no modification request on KNI library and
sample app.


Discussed alternatives were:
* Tun/Tap
This won't be as fast as KNI and performance is an issue.

* virtio-user + vhost-net
This can be valid alternative, removes the out of tree kernel module
need. But missing control path. Proof of concept work will be done.

* Bifurcated driver
Not able to filter all traffic, not a full functional alternative.

* Upstreaming kernel module:
Stephen suggested upstreaming a generic shim layer and use it.


Future of the KNI:
* Remove ethtool support ?
Still there is some interest, will keep it. But not able to extend it to
other drivers with current design.

* Remove KNI VHOST?
There were no interest for this feature. I will send a deprecation
notice to remove this, and we can discuss more there.

* What to do with out of tree kernel module
It is still problem for OSVs and unfortunately it is staying.

* Switch completely to an alternative approach?
There won't be an action for a switch. virtio-user + vhost-net
alternative will be investigated.

*KNI PMD
Patch is in the mail list, missing comments. If it gets some
interest/comments/acks it may go in to next release.

* Any improvement on library or sample app?
Nothing listed.


Thanks,
ferruh