Firstly, very sorry for so late review!

On Fri, Aug 25, 2017 at 09:40:50AM +0000, Jianfeng Tan wrote:

To support kick in secondary process, we propose callfd_pri and
kickfd_pri to store the value in primary process; and by a new
API, rte_vhost_set_vring_effective_fd(), we can set effective
callfd and kickfd which can be used by secondary process.

Note in this case, either primary process or the secondary process
can kick the frontend; that is, they cannot kick a vring at the
same time.

Since only one can work, why not just overwriting the fd? Say, you
could introudce some APIs like "rte_vhost_set_vring_callfd", then
you don't need to introduce few more fields like "callfd_pri".

	--yliu