source: postlfs/virtualization/qemu.xml@ f82ac3f

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;

  <!ENTITY qemu-download-http "http://wiki.qemu.org/download/qemu-&qemu-version;.tar.bz2">
  <!ENTITY qemu-download-ftp  " ">
  <!ENTITY qemu-md5sum        "3a897d722457c5a895cd6ac79a28fda0">
  <!ENTITY qemu-size          "11.5 MB">
  <!ENTITY qemu-buildsize     "193 MB">
  <!ENTITY qemu-time          "1.8 SBU">
]>

<sect1 id="qemu" xreflabel="qemu-&qemu-version;">
  <?dbhtml filename="qemu.html"?>

  <sect1info>
    <othername>$LastChangedBy$</othername>
    <date>$Date$</date>
  </sect1info>

  <title>qemu-&qemu-version;</title>

  <indexterm zone="qemu">
    <primary sortas="a-qemu">qemu</primary>
  </indexterm>

  <sect2 role="package">
    <title>Introduction to qemu</title>

    <para><application>qemu</application> is a full virtualization solution
    for Linux on x86 hardware containing virtualization extensions (Intel VT or
    AMD-V).</para>

    &lfs74_checked;

    <bridgehead renderas="sect3">Package Information</bridgehead>
    <itemizedlist spacing="compact">
      <listitem>
        <para>Download (HTTP): <ulink url="&qemu-download-http;"/></para>
      </listitem>
      <listitem>
        <para>Download (FTP): <ulink url="&qemu-download-ftp;"/></para>
      </listitem>
      <listitem>
        <para>Download MD5 sum: &qemu-md5sum;</para>
      </listitem>
      <listitem>
        <para>Download size: &qemu-size;</para>
      </listitem>
      <listitem>
        <para>Estimated disk space required: &qemu-buildsize;</para>
      </listitem>
      <listitem>
        <para>Estimated build time: &qemu-time;</para>
      </listitem>
    </itemizedlist>

    <bridgehead renderas="sect3">Qemu Dependencies</bridgehead>

    <bridgehead renderas="sect4">Required</bridgehead>
    <para role="required">
      <xref linkend="glib2"/>,
      <xref linkend="python2"/>,
      <xref linkend="sdl"/>, and
      <xref linkend="x-window-system"/>
    </para>

    <bridgehead renderas="sect4">Optional</bridgehead>
    <para role="optional">
      <xref linkend="alsa"/>,
      <xref linkend="attr"/>,
      <xref linkend="check"/>,
      <xref linkend="curl"/>,
      <xref linkend="mesalib"/>, and
      <xref linkend="cyrus-sasl"/>.
      Note that this optional dependencies list is not comprehensive.  See the
      output of <command>./configure --help</command> for a more complete list.
    </para>

    <para condition="html" role="usernotes">User Notes:
    <ulink url="&blfs-wiki;/qemu"/></para>

  </sect2>

  <sect2 id='qemu-prereq'>
    <title>KVM Prerequsites</title>

    <para>Before building <application>qemu</application>, check to see if
    your processor supports Virtualization Technology (VT):</para>

    <screen><userinput>egrep '^flags.*(vmx|svm)' /proc/cpuinfo</userinput></screen>

    <para>If you get any output, you have VT technology (vmx for Intel
    processors and svm for AMD processors).  You then need to go into your
    system BIOS and ensure it is enabled.  After enabing, reboot back to your
    LFS instance.</para>

  </sect2>

  <sect2 role="kernel" id='qemu-kernel'>
    <title>Kernel Configuration</title>

    <para>Enable the following options in the kernel configuration
    and recompile the kernel if necessary:</para>

<screen><literal>Virtualization: Y
  Kernel-based Virtual Machine (KVM) support: M or Y
  KVM for Intel processors support:           M or Y
  KVM for AMD processors support:             M or Y</literal></screen>

    <indexterm zone="qemu qemu-kernel">
      <primary sortas="d-qemu">qemu</primary>
    </indexterm>

    <para>The Intel or AMD settings are not both required, but the one matching
    your system processor is required.</para>

    <para>For networking, check that the settings CONFIG_BRIDGE, CONFIG_STP,
    CONFIG_TUN are enabled and <xref linkend='bridgeutils'/> is
    installed.</para>

  </sect2>

  <sect2 role="installation">
    <title>Installation of qemu</title>

    <para>If <application>xorg</application> is not installed in
    <filename class='directory'>/usr</filename>, then the linker needs to
    be told where it is.  For example:</para>

<screen><userinput>export LIBRARY_PATH=/opt/xorg/lib</userinput></screen>

    <para>Install <application>qemu</application> by running the following
    commands:</para>

<screen><userinput>./configure --prefix=/usr                \
            --sysconfdir=/etc            \
            --target-list=x86_64-softmmu &amp;&amp;
make</userinput></screen>

    <para>To run the built in tests, run <command>make V=1 check</command>.</para>

    <para>Now, as the <systemitem class="username">root</systemitem> user:</para>

<screen role="root"><userinput>make install</userinput></screen>
    
    <note><!--<para>The main program <command>qemu-system-x86_64</command> doesn't
    make a distinction between i386 and x86_64 so even on an i386 system you
    should use <emphasis>qemu-system-x86_64</emphasis></para>
    -->

    <para>For convenience you may want to create a symbolic link to run
    <command>qemu-system-x86_64</command>:</para>

    <screen><userinput>ln -sv qemu-system-x86_64 /usr/bin/qemu</userinput></screen>
    </note>

  </sect2>

  <sect2 role="commands">
    <title>Command Explanations</title>

    <para><parameter>--target-list=x86_64-softmmu</parameter>: This option
    limits the build target to the x86_64 architecture.  For other 
    hardware emulation see the --target-list list in <command>configure</command>'s
    help output.  Omitting this option will build all architectures.</para>

  </sect2>



  <sect2 role="configuration">
    <title>Configuring qemu</title>

    <para>To generate an image, run:</para>

    <screen><userinput>qemu-img create -f qcow2 vdisk.img 10G</userinput></screen>

    <para>Adjust the virtual disk size and image filename as desired.  The
    actual size of the file will be less than specified, but will expand as it
    is used.</para>

    <note><para>The following instructions assume you have created the optional
    symbolic link, <userinput>qemu</userinput>.  Additionally, you must run
    <userinput>qemu</userinput> from an X-Windows based terminal.</para></note>

    <para>To install an operating system, download an iso of your choice or use
    a pre-intalled cdrom device.  For the purposes of this example, use
    Fedora 16 that is downloaded as
    <filename>Fedora-16-x86_64-Live-LXDE.iso</filename> in the current
    directory.  Run the following:</para>

<screen><userinput>qemu -enable-kvm -hda vdisk.img            \
     -cdrom Fedora-16-x86_64-Live-LXDE.iso \
     -boot d                               \
     -m 384</userinput></screen>

    <para>Follow the normal installation procedures for the chosen
    distribution.  The -boot option specifies the boot order of drives as a
    string of drive letters. Valid drive letters are: a, b (floppy 1 and 2), c
    (first hard disk), d (first CD-ROM).  The -m option is the amount of memory
    to use for the virtual machine.  If you have sufficient memory (2G or
    more), 1G is a reasonable value.  For computers with 512MB of RAM it's safe
    to use -m 192, or even -m 128 (the default).  The -enable-kvm option allows
    for hardware acceleeration.  Without this switch, the emulation is
    relatively slow.</para>

    <para>To run the newly installed operating system, run:</para>

<screen><userinput>qemu -enable-kvm vdisk.img -m 384</userinput></screen>

    <para>To add networking to the instance add "-net nic -net user" to the
    command above.  qemu provides a DHCP server for the VM and, depending on
    the client system, sets up networking though the host.</para>

    <para>One problem with the above networking solution is that it does not
    provide the ability to connect with the local network.  To do that, there are
    several additional steps that need to be done, all as the <systemitem
    class="username">root</systemitem> user:</para>

    <itemizedlist spacing="compact">
      <listitem>
        <para>Set up bridging with <xref linkend='bridgeutils'/>.</para>
      </listitem>

      <listitem>
        <para>Allow the host system to forward IP packets.</para>

<screen><userinput>sysctl -w net.ipv4.ip_forward=1</userinput></screen>

        <para>To make this permanent, add the command to
        <filename>/etc/syssysctl.conf:</filename></para>

<screen><userinput>cat &gt;&gt; /etc/sysctl.conf &lt;&lt; EOF
net.ipv4.ip_forward=1
EOF</userinput></screen>

      </listitem>

      <listitem>
        <para>Create scripts for qemu to attach the client network
        device, usually visible as tap0, to the host bridge.</para>

<screen><userinput>cat &gt; /etc/qemu-ifup &lt;&lt; EOF
#!/bin/bash

switch=br0

if [ -n "\$1" ]; then
  # Add new tap0 interface to bridge
  /sbin/ip link set \$1 up
  sleep 0.5s
  /usr/sbin/brctl addif \$switch \$1
else
  echo "Error: no interface specified"
  exit 1
fi

exit 0
EOF

chmod +x /etc/qemu-ifup</userinput></screen>

<screen><userinput>cat &gt; /etc/qemu-ifdown &lt;&lt; EOF
#!/bin/bash

switch=br0

if [ -n "\$1" ]; then
  # Remove tap0 interface from bridge
  /usr/sbin/brctl delif \$switch \$1
else
  echo "Error: no interface specified"
  exit 1
fi

exit 0
EOF

chmod +x /etc/qemu-ifdown</userinput></screen>

      </listitem>
    </itemizedlist>

      <note><para>The backslashes in the abouve script are for convenience
      for cut/paste operations.  The backslashes should <emphasis>not</emphasis>
      appear in the final scripts.</para></note>

    <itemizedlist spacing="compact">
      <listitem>
        <para>Start qemu with "-net nic -net tap" options.  </para>
      </listitem>

      <listitem>
        <para>If a connection, such as ssh, from the local network to the
        client VM is desired, the client should probably be configured
        with a static IP address.</para>
      </listitem>

    </itemizedlist>

  </sect2>

  <sect2 role="content">
    <title>Contents</title>

    <segmentedlist>
      <segtitle>Installed Program</segtitle>
      <segtitle>Installed Libraries</segtitle>
      <segtitle>Installed Directories</segtitle>

      <seglistitem>
        <seg>qemu-ga, qemu-img, qemu-io, qemu-nbd, qemu-system-x86_64</seg>
        <seg>None</seg>
        <seg>/etc/qemu, /usr/share/qemu, /usr/share/doc/qemu</seg>
      </seglistitem>
    </segmentedlist>

    <variablelist>
      <bridgehead renderas="sect3">Short Description</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

      <varlistentry id="qemu-ga">
        <term><command>qemu-ga</command></term>
        <listitem>
          <para>implements support for QMP (QEMU Monitor Protocol) commands and
          events that terminate and originate respectively within the guest
          using an agent built as part of QEMU.</para>
          <indexterm zone="qemu qemu-ga">
            <primary sortas="b-qemu-ga">qemu-ga</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="qemu-img">
        <term><command>qemu-img</command></term>
        <listitem>
          <para>provides commands to manage QEMU disk images.</para>
          <indexterm zone="qemu qemu-img">
            <primary sortas="b-qemu-img">qemu-img</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="qemu-io">
        <term><command>qemu-io</command></term>
        <listitem>
          <para>is a diagnostic and manipulation program for (virtual) memory
          media.  It is still at an early stage of development.</para>
          <indexterm zone="qemu qemu-io">
            <primary sortas="b-qemu-io">qemu-io</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="qemu-nbd">
        <term><command>qemu-nbd</command></term>
        <listitem>
          <para>exports Qemu disk images using the QEMU Disk Network Block
          Device (NBD) protocol.</para>
          <indexterm zone="qemu qemu-nbd">
            <primary sortas="b-qemu-nbd">qemu-nbd</primary>
          </indexterm>
        </listitem>
      </varlistentry>

      <varlistentry id="qemu-system">
        <term><command>qemu-system-x86_64</command></term>
        <listitem>
          <para>is the QEMU PC System emulator.</para>
          <indexterm zone="qemu qemu-system">
            <primary sortas="b-qemu-system">qemu-system-x86_64</primary>
          </indexterm>
        </listitem>
      </varlistentry>

    </variablelist>

  </sect2>

</sect1>