[ovs-dev] [PATCH 1/8] doc: Add an overview of the 'dpdk' port
Stephen Finucane
stephen at that.guru
Mon Apr 16 12:45:01 UTC 2018
On Mon, 2018-04-09 at 15:15 +0000, Stokes, Ian wrote:
> > These ports are used to allow ingress/egress from the host and are
> > therefore _reasonably_ important. However, there is no clear overview of
> > what these ports actually are or why things are done the way they are.
> > Start closing this gap by providing a standalone example of using these
> > ports along with a little more detailed overview of the binding process.
> >
> > There is additional cleanup to be done for the DPDK howto, but that will
> > be done separately.
> >
> > Signed-off-by: Stephen Finucane <stephen at that.guru>
> > Cc: Ciara Loftus <ciara.loftus at intel.com>
> > Cc: Kevin Traynor <ktraynor at redhat.com>
> > ---
> > Documentation/topics/dpdk/index.rst | 1 +
> > Documentation/topics/dpdk/phy.rst | 111
> > ++++++++++++++++++++++++++++++++++++
> > 2 files changed, 112 insertions(+)
> > create mode 100644 Documentation/topics/dpdk/phy.rst
> >
> > diff --git a/Documentation/topics/dpdk/index.rst
> > b/Documentation/topics/dpdk/index.rst
> > index da148b323..5f836a6e9 100644
> > --- a/Documentation/topics/dpdk/index.rst
> > +++ b/Documentation/topics/dpdk/index.rst
> > @@ -28,5 +28,6 @@ The DPDK Datapath
> > .. toctree::
> > :maxdepth: 2
> >
> > + phy
> > vhost-user
> > ring
> > diff --git a/Documentation/topics/dpdk/phy.rst
> > b/Documentation/topics/dpdk/phy.rst
> > new file mode 100644
> > index 000000000..1c18e4e3d
> > --- /dev/null
> > +++ b/Documentation/topics/dpdk/phy.rst
> > @@ -0,0 +1,111 @@
> > +..
> > + Copyright 2018, Red Hat, Inc.
> > +
> > + Licensed under the Apache License, Version 2.0 (the "License"); you
> > may
> > + not use this file except in compliance with the License. You may
> > obtain
> > + a copy of the License at
> > +
> > + http://www.apache.org/licenses/LICENSE-2.0
> > +
> > + Unless required by applicable law or agreed to in writing, software
> > + distributed under the License is distributed on an "AS IS" BASIS,
> > WITHOUT
> > + WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
> > See the
> > + License for the specific language governing permissions and
> > limitations
> > + under the License.
> > +
> > + Convention for heading levels in Open vSwitch documentation:
> > +
> > + ======= Heading 0 (reserved for the title in a document)
> > + ------- Heading 1
> > + ~~~~~~~ Heading 2
> > + +++++++ Heading 3
> > + ''''''' Heading 4
> > +
> > + Avoid deeper levels because they do not render well.
> > +
> > +===================
> > +DPDK Physical Ports
> > +===================
> > +
> > +The DPDK datapath provides a way to attach DPDK-backed physical
> > +interfaces to allow high-performance ingress/egress from the host.
> > +
> > +.. versionchanged:: 2.7.0
> > +
> > + Before Open vSwitch 2.7.0, it was necessary to prefix port names with
> > a
> > + ``dpdk`` prefix. Starting with 2.7.0, this is no longer necessary.
> > +
> > +Quick Example
> > +-------------
> > +
> > +This example demonstrates how to bind two ``dpdk`` ports, bound to
> > +physical interfaces identified by hardware IDs ``0000:01:00.0`` and
> > +``0000:01:00.1``, to an existing bridge called ``br0``::
> > +
> > + $ ovs-vsctl add-port br0 dpdk-p0 \
> > + -- set Interface dpdk-p0 type=dpdk options:dpdk-
> > devargs=0000:01:00.0
> > + $ ovs-vsctl add-port br0 dpdk-p1 \
> > + -- set Interface dpdk-p1 type=dpdk
> > + options:dpdk-devargs=0000:01:00.1
> > +
> > +For the above example to work, the two physical interfaces must be
> > +bound to the DPDK poll-mode drivers in userspace rather than the
> > +traditional kernel drivers. See the `binding NIC drivers <dpdk-binding-
> > nics>` section for details.
>
> I think an example should be added here for when multiple ports share
> the same bus slot function.
>
> Support for this was added in as part of OVS 2.9.
>
> If not added here then we need to flag clearly that it's supported
> but that users need to consult the dpdk-binding-nic section for
> specifics.
This is only a quick intro so I don't think it would belong here.
However, we could definitely add this as another section. I'm not
familiar with this feature so would it be possible to submit this as a
follow-up? I'd be happy to review it from a docs perspective.
Stephen
> Ian
> > +
> > +.. _dpdk-binding-nics:
> > +
> > +Binding NIC Drivers
> > +-------------------
> > +
> > +DPDK operates entirely in userspace and, as a result, requires use of
> > +its own poll-mode drivers in user space for physical interfaces and a
> > +passthrough-style driver for the devices in kernel space.
> > +
> > +There are two different tools for binding drivers: :command:`driverctl`
> > +which is a generic tool for persistently configuring alternative device
> > +drivers, and :command:`dpdk-devbind` which is a DPDK-specific tool and
> > +whose changes do not persist across reboots. In addition, there are two
> > +options available for this kernel space driver - VFIO (Virtual Function
> > +I/O) and UIO (Userspace I/O) - along with a number of drivers for each
> > +option. We will demonstrate examples of both tools and will use the
> > +``vfio-pci`` driver, which is the more secure, robust driver of those
> > +available. More information can be found in the `DPDK documentation
> > <dpdk-drivers>`__.
> > +
> > +To list devices using :command:`driverctl`, run::
> > +
> > + $ driverctl -v list-devices | grep -i net
> > + 0000:07:00.0 igb (I350 Gigabit Network Connection (Ethernet Server
> > Adapter I350-T2))
> > + 0000:07:00.1 igb (I350 Gigabit Network Connection (Ethernet Server
> > + Adapter I350-T2))
> > +
> > +You can then bind one or more of these devices using the same tool::
> > +
> > + $ driverctl set-override 0000:07:00.0 vfio-pci
> > +
> > +Alternatively, to list devices using :command:`dpdk-devbind`, run::
> > +
> > + $ dpdk-devbind --status
> > + Network devices using DPDK-compatible driver
> > + ============================================
> > + <none>
> > +
> > + Network devices using kernel driver
> > + ===================================
> > + 0000:07:00.0 'I350 Gigabit Network Connection 1521' if=enp7s0f0
> > drv=igb unused=igb_uio
> > + 0000:07:00.1 'I350 Gigabit Network Connection 1521' if=enp7s0f1
> > + drv=igb unused=igb_uio
> > +
> > + Other Network devices
> > + =====================
> > + ...
> > +
> > +Once again, you can then bind one or more of these devices using the
> > +same
> > +tool::
> > +
> > + $ dpdk-devbind --bind=vfio-pci 0000:07:00.0
> > +
> > +.. versionchanged:: 2.6.0
> > +
> > + Open vSwitch 2.6.0 added support for DPDK 16.07, which in turn renamed
> > the
> > + former ``dpdk_nic_bind`` tool to ``dpdk-devbind``.
> > +
> > +For more information, refer to the `DPDK documentation <dpdk-drivers>`__.
> > +
> > +.. _dpdk-drivers:
> > +http://dpdk.org/doc/guides/linux_gsg/linux_drivers.html
> > --
> > 2.14.3
> >
> > _______________________________________________
> > dev mailing list
> > dev at openvswitch.org
> > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
More information about the dev
mailing list