openstack-manuals/doc/common/section_kvm_enable.xml

<?xml version="1.0" encoding="UTF-8"?>
<section xmlns="http://docbook.org/ns/docbook"
    xmlns:xi="http://www.w3.org/2001/XInclude"
    xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
    xml:id="section_kvm_enable">
  <title>Enabling KVM</title>
  <para>To perform the following steps, you must be logged in as
        the <systemitem>root</systemitem> user.</para>
        <procedure>
            <step>
                <para>To determine whether the <literal>svm</literal>
                    or <literal>vmx</literal> CPU extensions are
                    present, run the following command:</para>
                <screen><prompt>#</prompt> <userinput>grep -E 'svm|vmx' /proc/cpuinfo</userinput></screen>
                <para>This command generates output if the CPU is
                    hardware-virtualization capable. Even if output is
                    shown, you may still need to enable virtualization
                    in the system BIOS for full support.</para>
                <para>If no output appears, consult your system
                    documentation to ensure that your CPU and
                    motherboard support hardware virtualization.
                    Verify that any relevant hardware virtualization
                    options are enabled in the system BIOS.</para>
                <para>Each manufacturer's BIOS is different. If you need to enable virtualization in
                the BIOS, look for an option containing the words "virtualization", "VT", "VMX", or
                "SVM." </para>
            </step>
            <step>
                <para>To list the loaded kernel modules and verify
                    that the <literal>kvm</literal> modules are
                    loaded, run the following command:</para>
                <screen><prompt>#</prompt> <userinput>lsmod | grep kvm</userinput></screen>
                <para>If the output includes <systemitem>kvm_intel</systemitem> or
                    <systemitem>kvm_amd</systemitem>, the <systemitem>kvm</systemitem> hardware
                virtualization modules are loaded and your kernel meets the module requirements for
                OpenStack Compute.</para>
                <para>If the output does not show that the kvm module
                    is loaded, run the following command to load
                    it:</para>
                <screen><prompt>#</prompt> <userinput>modprobe -a kvm</userinput></screen>
                <para>Run the command for your CPU. For Intel, run
                    this command:</para>
                <screen><prompt>#</prompt> <userinput>modprobe -a kvm-intel</userinput></screen>
                <para>For AMD, run this command:</para>
                <screen><prompt>#</prompt> <userinput>modprobe -a kvm-amd</userinput></screen>
                <para>Because a KVM installation can change user group
                    membership, you might need to log in again for
                    changes to take effect.</para>
            <para>If the kernel modules do not load automatically, please use the procedures listed
                in the subsections below.</para>
            </step>
        </procedure>
        <para>This completes the required checks to ensure that
            hardware virtualization support is available and enabled,
            and that the correct kernel modules are loaded.</para>
        <para>If the checks indicate that required hardware
            virtualization support or kernel modules are disabled or
            not available, you must either enable this support on the
            system or find a system with this support.</para>
        <note>
            <para>Some systems require that you enable VT support in
                the system BIOS. If you believe your processor
                supports hardware acceleration but the previous
                command did not produce output, you might need to
                reboot your machine, enter the system BIOS, and enable
                the VT option.</para>
        </note>
        <para>If KVM acceleration is not supported, configure Compute
            to use a different hypervisor, such as <link
                xlink:href="http://docs.openstack.org/trunk/config-reference/content/qemu.html"
                >QEMU</link> or <link
                xlink:href="http://docs.openstack.org/trunk/config-reference/content/introduction-to-xen.html"
                >Xen</link>.</para>
        <para>The following procedures will help you load the kernel modules for Intel-based and
        AMD-based processors if they did not load automatically during KVM installation.</para>
        <section xml:id="kvm-intel">
            <title>Intel-based processors</title>
            <para>If your compute host is Intel-based, run the
                following command as root to load the kernel
                modules:</para>
            <screen><prompt>#</prompt> <userinput>modprobe kvm</userinput>
<prompt>#</prompt> <userinput>modprobe kvm-intel</userinput></screen>
            <para>Add the following lines to the
                    <filename>/etc/modules</filename> file so that
                these modules load on reboot:</para>
            <programlisting>kvm
kvm-intel</programlisting>
        </section>
        <section xml:id="kvm-amd">
            <title>AMD-based processors</title>
            <para>If your compute host is AMD-based, run the following
                command as root to load the kernel modules:</para>
            <screen><prompt>#</prompt> <userinput>modprobe kvm</userinput>
<prompt>#</prompt> <userinput>modprobe kvm-amd</userinput></screen>
            <para>Add the following lines to
                    <filename>/etc/modules</filename> file so that
                these modules load on reboot:</para>
            <programlisting>kvm
kvm-amd</programlisting>
        </section>
</section>