Add instructions for using Open vSwitch with KVM.

INSTALL.KVM

@@ -0,0 +1,83 @@
+                 How to Use Open vSwitch with KVM
+                 =================================
+
+This document describes how to use Open vSwitch with the Kernel-based
+Virtual Machine (KVM). This document assumes that you have read and
+followed INSTALL.Linux to get Open vSwitch setup on your Linux system
+
+Setup
+-----
+
+First, follow the setup instructions in INSTALL.Linux to get a working
+Open vSwitch installation.
+
+KVM uses tunctl to handle various bridging modes, which you can 
+install with the Debian/Ubuntu package uml-utilities.
+
+      % apt-get install uml-utilities
+
+Next, you will need to modify or create custom versions of the qemu-ifup
+and qemu-ifdown scripts. In this guide, we'll create custom versions
+that make use of example open vSwitch bridges that we'll describe in this
+guide.
+
+Create the following two files and store them in known locations.
+
+For example /etc/ovs-ifup and /etc/ifdown
+
+/etc/ovs-ifup
+--------------------------------------------------------------------
+#!/bin/sh
+
+switch='br0'
+/sbin/ifconfig $1 0.0.0.0 up
+ovs-vsctl add-port ${switch} $1
+--------------------------------------------------------------------
+
+/etc/ovs-ifdown
+--------------------------------------------------------------------
+#!/bin/sh
+
+switch='br0'
+/sbin/ifconfig $1 0.0.0.0 down
+ovs-vsctl del-port ${switch} $1
+--------------------------------------------------------------------
+
+At the end of INSTALL.Linux, it describes basic usage of creating 
+bridges and ports. If you haven't already, create a bridge named
+br0 with the following command:
+
+      % ovs-vsctl add-br br0
+
+Then, add a port to the bridge for the NIC that you want your guests
+to communicate over (e.g. eth0):
+
+      % ovs-vsctl add-port br0 eth0
+
+Please refer to ovs-vsctl(8) for more details.
+
+Next, we'll start a guest that will use our ifup and ifdown scripts.
+
+      % kvm -m 512 -net nic,maddr=00:11:22:EE:EE:EE -net \
+tap,script=/etc/ovs-ifup,downscript=/etc/ovs-ifdown -drive \
+file=/path/to/disk-image,boot=on
+
+This will start the guest and associate a tap device with it. The 
+ovs-ifup script will add a port on the br0 bridge so that the
+guest will be able to communicate over that bridge.
+
+To get some more information and for debugging you can use Open
+vSwitch utilities such as ovs-dpctl and ovs-ofctl, For example:
+
+      % ovs-dpctl show br0 
+      % ovs-ofctl show br0
+
+You should see tap devices for each KVM guest added as ports to 
+the bridge (e.g. tap0)
+
+Please refer to ovs-dpctl(8) and ovs-ofctl(8) for more details.
+
+Bug Reporting
+-------------
+
+Please report problems to bugs@openvswitch.org.

Makefile.am

@@ -29,6 +29,7 @@ BUILT_SOURCES =
 CLEANFILES =
 DISTCLEANFILES =
 EXTRA_DIST = INSTALL.bridge \
+	INSTALL.KVM \
 	INSTALL.Linux \
 	INSTALL.userspace \
 	INSTALL.OpenFlow \

README

@@ -98,6 +98,9 @@ read INSTALL.bridge.
 To build RPMs for installing Open vSwitch on a Citrix XenServer host
 or resource pool, read INSTALL.XenServer.
 
+To use Open vSwitch with KVM on Linux, read INSTALL.Linux, then
+INSTALL.KVM.
+
 To install Open vSwitch without using a kernel module, read
 INSTALL.userspace.