[ovs-dev] [PATCH v2] INSTALL.DPDK: Add notes regarding vhost multiq configuration.

[Stokes, Ian]

> Hi, Ian.
> I prepared a fix for this problem here:
> http://openvswitch.org/pipermail/dev/2016-February/066066.html
> 
> Maybe it will be better than note in documentation.
> 
> Best regards, Ilya Maximets.

Thanks for the heads up on this Ilya, am I right in thinking this removes the need to call ethtool -L in the guest VM?

> 
> On 09.02.2016 17:40, Ian Stokes wrote:
> > Linux kernel network devices in a guest should have the number of
> > multi-purpose channels configured when used with DPDK multiqueue on
> the host.
> > This commit adds an example of how this can be done. Also add QEMU 2.5
> > requirements for multiqueue with DPDK in NEWS.
> >
> > Signed-off-by: Ian Stokes <ian.stokes at intel.com>
> > ---
> >  INSTALL.DPDK.md |   17 +++++++++++++++++
> >  NEWS            |    2 +-
> >  2 files changed, 18 insertions(+), 1 deletions(-)
> >
> > diff --git a/INSTALL.DPDK.md b/INSTALL.DPDK.md index d892788..e9f9acc
> > 100644
> > --- a/INSTALL.DPDK.md
> > +++ b/INSTALL.DPDK.md
> > @@ -586,6 +586,23 @@ Follow the steps below to attach vhost-user
> port(s) to a VM.
> >     -device virtio-net-
> pci,mac=00:00:00:00:00:02,netdev=mynet2,mq=on,vectors=$v
> >     ```
> >
> > +   Also, the driver in the guest operating system must be configured
> to use
> > +   the exact same number of queues. If the number of queues is less
> than $q,
> > +   then packets that are enqueued to queues unused by guest will not
> be
> > +   received.
> > +
> > +   This can be done for the Linux kernel virtio-net driver with:
> > +
> > +   ```
> > +   ethtool -L <DEV> combined <$q>
> > +   ```
> > +
> > +   A note on the command above:
> > +
> > +   `-L`: Changes the numbers of channels of the specified network
> > + device
> > +
> > +   `combined`: Changes the number of multi-purpose channels.
> > +
> >  DPDK vhost-cuse:
> >  ----------------
> >
> > diff --git a/NEWS b/NEWS
> > index 3e33871..2d1b8fb 100644
> > --- a/NEWS
> > +++ b/NEWS
> > @@ -55,7 +55,7 @@ v2.5.0 - xx xxx xxxx
> >     - DPDK:
> >       * Requires DPDK 2.2
> >       * Added multiqueue support to vhost-user
> > -
> > +     * Note: QEMU 2.5+ required for multiqueue support
> >
> >  v2.4.0 - 20 Aug 2015
> >  ---------------------
> >