[dpdk-stable] please help backporting some patches to stable release 18.08.1

[Kevin Traynor <ktraynor@redhat.com>]

Hi commit authors (and maintainers),

I didn't manage to apply following commits from upstream to stable branch
18.08: conflict happens. I'm wondering can the authors check the following
list and backport those patches belong to you?

FYI, branch 18.08 is located at tree:
   git://dpdk.org/dpdk-stable

It'd be great if you could do that in one or two weeks. Also, please add a
heading line like below before the commit log body:
    [ backported from upstream commit xxx ]

Example: http://dpdk.org/browse/dpdk-stable/commit/?h=16.07&id=c4831394c7d1944d8ec27d52c22997f20d19718e

Also please mention the target stable in the subject line, as we have more than one
at the same time, for example:

    [PATCH 18.08] foo/bar: fix baz

With git send-email, this can be achieved by appending the parameter:

    --subject-prefix='18.08'

Please let me know if you have any comments, say, need more time, or it's
worthless to packport it. And please send it to "stable@dpdk.org", but not
"dev@dpdk.org".

Thanks.

Kevin Traynor

---
40f8e9c28  Honnappa Nagarahalli hash: separate multi-writer from r/w concurrency
57b4d90b5  Maxime Coquelin  vhost: fix payload size of reply
c4301b9ca  Viacheslav Ovsiienko net/mlx5: fix flow counters creation
57660eba7  Yipeng Wang      test/hash: add r/w concurrency to autotest