Re: [Qemu-devel] [wiki] New wiki page - vhost-user setup with ovs/dpdk backend

[Flavio Leitner]

On Thu, Sep 17, 2015 at 01:08:36PM +0300, Marcel Apfelbaum wrote:
> On 09/16/2015 08:44 PM, Flavio Leitner wrote:
> >On Thu, Sep 10, 2015 at 10:51:19PM +0300, Marcel Apfelbaum wrote:
> >>Hi,
> >>
> >>The page describes how to setup an environment that allows 
> >>testing/developing
> >>vhost-user using ovs (with dpdk) as backend.
> >>
> >>A regular pc machine can be used, no need for several hosts, a 'dpdk 
> >>enabled' NIC or 1G huge-pages.
> >>
> >>The goal is to connect guests' virtio-net devices having vhost-user backend 
> >>to OVS dpdkvhostuser ports
> >>and be able to run any kind of network traffic between them.
> >>
> >>The page can be found at:
> >>http://wiki.qemu.org/Features/vhost-user-ovs-dpdk
> >>
> >>I want to keep it as simple as possible.
> >>If you see steps that can be skipped or unneeded configuration please let 
> >>me know
> >>or feel free to update the page.
> >
> >I gave a quick look and found couple issues.  It seems to be missing
> >the installing steps for qemu.  Also the eventfd_link module is only
> >needed for vhost-cuse, so you don't need to build/install/load at all.
> Hi Flavio,
> Thank you for reviewing the document!
> 
> For some reason I thought we still need eventfd_link to notify the guests
> when new packets arrive. Indeed we don't need this anymore, I updated the 
> wiki page.

We use the one provided by kernel.  The eventfd_link on DPDK is special for
vhost-cuse: 
https://github.com/openvswitch/ovs/blob/master/INSTALL.DPDK.md#dpdk-vhost-cuse-prerequisites


> Regarding QEMU, can you please point me to the missing setup steps?
> (I think I already took care of them, anyway I want to be sure)

Yup, I missed that you are running qemu from the builddir, not from
the system, so you don't need to install it.

Thanks again,
fbl