We include refrences from the physical and vhost-user interface guides.
Signed-off-by: Stephen Finucane <step...@that.guru>
---
v2:
- Don't split the document into multiple docs
---
Documentation/howto/dpdk.rst | 52 ++--------------------
Documentation/topics/dpdk/index.rst | 1 +
Documentation/topics/dpdk/jumbo-frames.rst | 71 ++++++++++++++++++++++++++++++
Documentation/topics/dpdk/phy.rst | 6 +++
Documentation/topics/dpdk/vhost-user.rst | 6 +++
5 files changed, 87 insertions(+), 49 deletions(-)
create mode 100644 Documentation/topics/dpdk/jumbo-frames.rst
diff --git a/Documentation/howto/dpdk.rst b/Documentation/howto/dpdk.rst
index 1a0fb6df1..e65e7dfaa 100644
--- a/Documentation/howto/dpdk.rst
+++ b/Documentation/howto/dpdk.rst
@@ -48,9 +48,9 @@ number of dpdk devices found in the log file::
$ ovs-vsctl add-port br0 dpdk-p1 -- set Interface dpdk-p1 type=dpdk \
options:dpdk-devargs=0000:01:00.1
-Some NICs (i.e. Mellanox ConnectX-3) have only one PCI address associated
-with multiple ports. Using a PCI device like above won't work. Instead, below
-usage is suggested::
+Some NICs (i.e. Mellanox ConnectX-3) have only one PCI address associated with
+multiple ports. Using a PCI device like above won't work. Instead, below usage
+is suggested::
$ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \
options:dpdk-devargs="class=eth,mac=00:11:22:33:44:55:01"
@@ -85,52 +85,6 @@ To stop ovs-vswitchd & delete bridge, run::
$ ovs-appctl -t ovsdb-server exit
$ ovs-vsctl del-br br0
-Jumbo Frames
-------------
-
-By default, DPDK ports are configured with standard Ethernet MTU (1500B). To
-enable Jumbo Frames support for a DPDK port, change the Interface's
-``mtu_request`` attribute to a sufficiently large value. For example, to add a
-DPDK Phy port with MTU of 9000::
-
- $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \
- options:dpdk-devargs=0000:01:00.0 mtu_request=9000
-
-Similarly, to change the MTU of an existing port to 6200::
-
- $ ovs-vsctl set Interface dpdk-p0 mtu_request=6200
-
-Some additional configuration is needed to take advantage of jumbo frames with
-vHost ports:
-
-1. *mergeable buffers* must be enabled for vHost ports, as demonstrated in the
- QEMU command line snippet below::
-
- -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \
- -device virtio-net-pci,mac=00:00:00:00:00:01,netdev=mynet1,mrg_rxbuf=on
-
-2. Where virtio devices are bound to the Linux kernel driver in a guest
- environment (i.e. interfaces are not bound to an in-guest DPDK driver), the
- MTU of those logical network interfaces must also be increased to a
- sufficiently large value. This avoids segmentation of Jumbo Frames received
- in the guest. Note that 'MTU' refers to the length of the IP packet only,
- and not that of the entire frame.
-
- To calculate the exact MTU of a standard IPv4 frame, subtract the L2 header
- and CRC lengths (i.e. 18B) from the max supported frame size. So, to set
- the MTU for a 9018B Jumbo Frame::
-
- $ ip link set eth1 mtu 9000
-
-When Jumbo Frames are enabled, the size of a DPDK port's mbuf segments are
-increased, such that a full Jumbo Frame of a specific size may be accommodated
-within a single mbuf segment.
-
-Jumbo frame support has been validated against 9728B frames, which is the
-largest frame size supported by Fortville NIC using the DPDK i40e driver, but
-larger frames and other DPDK NIC drivers may be supported. These cases are
-common for use cases involving East-West traffic only.
-
.. _dpdk-ovs-in-guest:
OVS with DPDK Inside VMs
diff --git a/Documentation/topics/dpdk/index.rst
b/Documentation/topics/dpdk/index.rst
index d083d929e..181f61abb 100644
--- a/Documentation/topics/dpdk/index.rst
+++ b/Documentation/topics/dpdk/index.rst
@@ -39,3 +39,4 @@ The DPDK Datapath
/topics/dpdk/pmd
/topics/dpdk/qos
/topics/dpdk/pdump
+ /topics/dpdk/jumbo-frames
diff --git a/Documentation/topics/dpdk/jumbo-frames.rst
b/Documentation/topics/dpdk/jumbo-frames.rst
new file mode 100644
index 000000000..692b291ac
--- /dev/null
+++ b/Documentation/topics/dpdk/jumbo-frames.rst
@@ -0,0 +1,71 @@
+..
+ 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.
+
+============
+Jumbo Frames
+============
+
+By default, DPDK ports are configured with standard Ethernet MTU (1500B). To
+enable Jumbo Frames support for a DPDK port, change the Interface's
+``mtu_request`` attribute to a sufficiently large value. For example, to add a
+:doc:`DPDK physical port <phy>` with an MTU of 9000, run::
+
+ $ ovs-vsctl add-port br0 dpdk-p0 -- set Interface dpdk-p0 type=dpdk \
+ options:dpdk-devargs=0000:01:00.0 mtu_request=9000
+
+Similarly, to change the MTU of an existing port to 6200, run::
+
+ $ ovs-vsctl set Interface dpdk-p0 mtu_request=6200
+
+Some additional configuration is needed to take advantage of jumbo frames with
+:doc:`vHost User ports <vhost-user>`:
+
+- *Mergeable buffers* must be enabled for vHost User ports, as demonstrated in
+ the QEMU command line snippet below::
+
+ -netdev type=vhost-user,id=mynet1,chardev=char0,vhostforce \
+ -device virtio-net-pci,mac=00:00:00:00:00:01,netdev=mynet1,mrg_rxbuf=on
+
+- Where virtio devices are bound to the Linux kernel driver in a guest
+ environment (i.e. interfaces are not bound to an in-guest DPDK driver), the
+ MTU of those logical network interfaces must also be increased to a
+ sufficiently large value. This avoids segmentation of Jumbo Frames received
+ in the guest. Note that 'MTU' refers to the length of the IP packet only, and
+ not that of the entire frame.
+
+ To calculate the exact MTU of a standard IPv4 frame, subtract the L2 header
+ and CRC lengths (i.e. 18B) from the max supported frame size. So, to set the
+ MTU for a 9018B Jumbo Frame::
+
+ $ ip link set eth1 mtu 9000
+
+When Jumbo Frames are enabled, the size of a DPDK port's mbuf segments are
+increased, such that a full Jumbo Frame of a specific size may be accommodated
+within a single mbuf segment.
+
+Jumbo frame support has been validated against 9728B frames, which is the
+largest frame size supported by Fortville NIC using the DPDK i40e driver, but
+larger frames and other DPDK NIC drivers may be supported. These cases are
+common for use cases involving East-West traffic only.
diff --git a/Documentation/topics/dpdk/phy.rst
b/Documentation/topics/dpdk/phy.rst
index c0931b2c4..477b291e4 100644
--- a/Documentation/topics/dpdk/phy.rst
+++ b/Documentation/topics/dpdk/phy.rst
@@ -218,3 +218,9 @@ If the log is not seen then the port can be detached like
so::
For more information please refer to the `DPDK Port Hotplug Framework`__.
__ http://dpdk.org/doc/guides/prog_guide/port_hotplug_framework.html#hotplug
+
+Jumbo Frames
+------------
+
+DPDK physical ports can be configured to use Jumbo Frames. For more
+information, refer to :doc:`jumbo-frames`.
diff --git a/Documentation/topics/dpdk/vhost-user.rst
b/Documentation/topics/dpdk/vhost-user.rst
index 168d5c5ce..67eb77d43 100644
--- a/Documentation/topics/dpdk/vhost-user.rst
+++ b/Documentation/topics/dpdk/vhost-user.rst
@@ -444,6 +444,12 @@ Sample XML
.. _QEMU documentation:
http://git.qemu-project.org/?p=qemu.git;a=blob;f=docs/specs/vhost-user.txt;h=7890d7169;hb=HEAD
+Jumbo Frames
+------------
+
+DPDK vHost User ports can be configured to use Jumbo Frames. For more
+information, refer to :doc:`jumbo-frames`.
+
vhost-user Dequeue Zero Copy (experimental)
-------------------------------------------
--
2.14.3
_______________________________________________
dev mailing list
d...@openvswitch.org
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
