INSTALL.KVM.md

   1 How to Use Open vSwitch with KVM
   2 =================================
   3
   4 This document describes how to use Open vSwitch with the Kernel-based
   5 Virtual Machine (KVM). This document assumes that you have read and
   6 followed [INSTALL.md] to get Open vSwitch setup on your Linux system.
   7
   8 Setup
   9 -----
  10
  11 First, follow the setup instructions in [INSTALL.md] to get a working
  12 Open vSwitch installation.
  13
  14 KVM uses tunctl to handle various bridging modes, which you can
  15 install with the Debian/Ubuntu package uml-utilities.
  16
  17       % apt-get install uml-utilities
  18
  19 Next, you will need to modify or create custom versions of the qemu-ifup
  20 and qemu-ifdown scripts. In this guide, we'll create custom versions
  21 that make use of example Open vSwitch bridges that we'll describe in this
  22 guide.
  23
  24 Create the following two files and store them in known locations.
  25
  26 For example /etc/ovs-ifup and /etc/ovs-ifdown
  27
  28 /etc/ovs-ifup
  29
  30 ```
  31 #!/bin/sh
  32
  33 switch='br0'
  34 /sbin/ifconfig $1 0.0.0.0 up
  35 ovs-vsctl add-port ${switch} $1
  36 ```
  37
  38 /etc/ovs-ifdown
  39
  40 ```
  41 #!/bin/sh
  42
  43 switch='br0'
  44 /sbin/ifconfig $1 0.0.0.0 down
  45 ovs-vsctl del-port ${switch} $1
  46 ```
  47
  48 At the end of [INSTALL.md], it describes basic usage of creating
  49 bridges and ports. If you haven't already, create a bridge named
  50 br0 with the following command:
  51
  52       % ovs-vsctl add-br br0
  53
  54 Then, add a port to the bridge for the NIC that you want your guests
  55 to communicate over (e.g. eth0):
  56
  57       % ovs-vsctl add-port br0 eth0
  58
  59 Please refer to ovs-vsctl(8) for more details.
  60
  61 Next, we'll start a guest that will use our ifup and ifdown scripts.
  62
  63       % kvm -m 512 -net nic,macaddr=00:11:22:EE:EE:EE -net \
  64         tap,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown -drive \
  65         file=/path/to/disk-image,boot=on
  66
  67 This will start the guest and associate a tap device with it. The
  68 ovs-ifup script will add a port on the br0 bridge so that the
  69 guest will be able to communicate over that bridge.
  70
  71 To get some more information and for debugging you can use Open
  72 vSwitch utilities such as ovs-dpctl and ovs-ofctl, For example:
  73
  74       % ovs-dpctl show
  75       % ovs-ofctl show br0
  76
  77 You should see tap devices for each KVM guest added as ports to
  78 the bridge (e.g. tap0)
  79
  80 Please refer to ovs-dpctl(8) and ovs-ofctl(8) for more details.
  81
  82 Bug Reporting
  83 -------------
  84
  85 Please report problems to bugs@openvswitch.org.
  86
  87 [INSTALL.md]:INSTALL.md