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    <h1>Node devices XML format</h1>

    <ul id="toc"></ul>

    <h2><a name="NodedevAttributes">Node Device XML</a></h2>

    <p>
      There are several libvirt functions, all with the
      prefix <code>virNodeDevice</code>, which deal with management of
      host devices that can be handed to guests via passthrough as
      &lt;hostdev&gt; elements
      in <a href="formatdomain.html#elementsHostDev">the domain XML</a>.
      These devices are represented as a hierarchy, where a device on
      a bus has a parent of the bus controller device; the root of the
      hierarchy is the node named "computer".
    </p>

    <p>
      When represented in XML, a node device uses the
      top-level <code>device</code> element, with the following
      elements present according to the type of device:
    </p>
    <dl>
      <dt><code>name</code></dt>
      <dd>The name for this device.  The name will be alphanumeric,
        with words separated by underscore.  For many devices, the
        name is just the bus type and address, as in
        "pci_0000_00_02_1" or "usb_1_5_3", but some devices are able
        to provide more specific names, such as
        "net_eth1_00_27_13_6a_fe_00".
      </dd>
      <dt><code>parent</code></dt>
      <dd>If this element is present, it names the parent device (that
        is, a controller to which this node belongs).
      </dd>
      <dt><code>capability</code></dt>
      <dd>This node appears for each capability that libvirt
        associates with a node.  A mandatory
        attribute <code>type</code> lists which category the device
        belongs to, and controls which further subelements will be
        present to describe the node:
        <dl>
          <dt><code>system</code></dt>
          <dd>Describes the overall host.  Sub-elements include:
            <dl>
              <dt><code>product</code></dt>
              <dd>If present, a simple text string giving the product
                name of the system.</dd>
              <dt><code>hardware</code></dt>
              <dd>Describes the hardware of the system, including
                sub-elements for <code>vendor</code>, <code>version</code>,
                <code>serial</code>, and <code>uuid</code>.</dd>
              <dt><code>firmware</code></dt>
              <dd>Describes the firmware of the system, including
                sub-elements for <code>vendor</code>, <code>version</code>,
                and <code>release_date</code>.</dd>
            </dl>
          </dd>
          <dt><code>pci</code></dt>
          <dd>Describes a device on the host's PCI bus.  Sub-elements
            include:
            <dl>
              <dt><code>domain</code></dt>
              <dd>Which domain the device belongs to.</dd>
              <dt><code>bus</code></dt>
              <dd>Which bus within the domain.</dd>
              <dt><code>slot</code></dt>
              <dd>Which slot within the bus.</dd>
              <dt><code>function</code></dt>
              <dd>Which function within the slot.</dd>
              <dt><code>product</code></dt>
              <dd>Product details from the device ROM, including an
                attribute <code>id</code> with the hexadecimal product
                id, and an optional text description of that id.</dd>
              <dt><code>vendor</code></dt>
              <dd>Vendor details from the device ROM, including an
                attribute <code>id</code> with the hexadecimal vendor
                id, and an optional text name of that vendor.</dd>
              <dt><code>iommuGroup</code></dt>
              <dd>
                This optional element describes the "IOMMU group" this
                device belongs to. If the element exists, it has a
                mandatory <code>number</code> attribute which tells
                the group number used for management of the group (all
                devices in group "n" will be found in
                "/sys/kernel/iommu_groups/n"). It will also have a
                list of <code>address</code> subelements, each
                containing the PCI address of a device in the same
                group. The toplevel device will itself be included in
                this list.
              </dd>
              <dt><code>capability</code></dt>
              <dd>
                This optional element can occur multiple times. If it
                exists, it has a mandatory <code>type</code> attribute
                which will be set to
                either <code>physical_function</code>
                or <code>virtual_functions</code>. If the type
                is <code>physical_function</code>, there will be a
                single <code>address</code> subelement which contains
                the PCI address of the SRIOV Physical Function (PF)
                that is the parent of this device (and this device is,
                by implication, an SRIOV Virtual Function (VF)). If
                the type is <code>virtual_functions</code>, then this
                device is an SRIOV PF, and the capability element will
                have a list of <code>address</code> subelements, one
                for each VF on this PF.
              </dd>
              <dt><code>numa</code></dt>
              <dd>
                This optional element contains information on the PCI device
                with respect to NUMA. For example, the optional
                <code>node</code> attribute tells which NUMA node is the PCI
                device associated with.
              </dd>
              <dt><code>pci-express</code></dt>
              <dd>
              This optional element contains information on PCI Express part of
              the device. For example, it can contain a child element
              <code>link</code> which addresses the PCI Express device's link.
              While a device has it's own capabilities
              (<code>validity='cap'</code>), the actual run time capabilities
              are negotiated on the device initialization
              (<code>validity='sta'</code>). The <code>link</code> element then
              contains three attributes: <code>port</code> which says in which
              port is the device plugged in, <code>speed</code> (in
              GigaTransfers per second) and <code>width</code> for the number
              of lanes used. Since the port can't be negotiated, it's not
              exposed in <code>./pci-express/link/[@validity='sta']</code>.
              </dd>
            </dl>
          </dd>
          <dt><code>usb_device</code></dt>
          <dd>Describes a device on the host's USB bus, based on its
            location within the bus.  Sub-elements include:
            <dl>
              <dt><code>bus</code></dt>
              <dd>Which bus the device belongs to.</dd>
              <dt><code>device</code></dt>
              <dd>Which device within the bus.</dd>
              <dt><code>product</code></dt>
              <dd>Product details from the device ROM, including an
                attribute <code>id</code> with the hexadecimal product
                id, and an optional text description of that id.</dd>
              <dt><code>vendor</code></dt>
              <dd>Vendor details from the device ROM, including an
                attribute <code>id</code> with the hexadecimal vendor
                id, and an optional text name of that vendor.</dd>
            </dl>
          </dd>
          <dt><code>usb</code></dt>
          <dd>Describes a USB device, based on its advertised driver
            interface.  Sub-elements include:
            <dl>
              <dt><code>number</code></dt>
              <dd>The device number.</dd>
              <dt><code>class</code></dt>
              <dd>The device class.</dd>
              <dt><code>subclass</code></dt>
              <dd>The device subclass.</dd>
              <dt><code>protocol</code></dt>
              <dd>The device protocol.</dd>
              <dt><code>description</code></dt>
              <dd>If present, a description of the device.</dd>
            </dl>
          </dd>
          <dt><code>net</code></dt>
          <dd>Describes a device capable for use as a network
            interface.  Sub-elements include:
            <dl>
              <dt><code>interface</code></dt>
              <dd>The interface name tied to this device.</dd>
              <dt><code>address</code></dt>
              <dd>If present, the MAC address of the device.</dd>
              <dt><code>link</code></dt>
              <dd>Optional to reflect the status of the link. It has
                two optional attributes: <code>speed</code> in Mbits per
                second and <code>state</code> to tell the state of the
                link. So far, the whole element is just for output,
                not setting.
              </dd>
              <dt><code>feature</code></dt>
              <dd>If present, the hw offloads supported by this network
                interface. Possible features are:
                <dl>
                    <dt><code>rx</code></dt><dd>rx-checksumming</dd>
                    <dt><code>tx</code></dt><dd>tx-checksumming</dd>
                    <dt><code>sg</code></dt><dd>scatter-gather</dd>
                    <dt><code>tso</code></dt><dd>tcp-segmentation-offload</dd>
                    <dt><code>ufo</code></dt><dd>udp-fragmentation-offload</dd>
                    <dt><code>gso</code></dt><dd>generic-segmentation-offload</dd>
                    <dt><code>gro</code></dt><dd>generic-receive-offload</dd>
                    <dt><code>lro</code></dt><dd>large-receive-offload</dd>
                    <dt><code>rxvlan</code></dt><dd>rx-vlan-offload</dd>
                    <dt><code>txvlan</code></dt><dd>tx-vlan-offload</dd>
                    <dt><code>ntuple</code></dt><dd>ntuple-filters</dd>
                    <dt><code>rxhash</code></dt><dd>receive-hashing</dd>
                </dl>
              </dd>
              <dt><code>capability</code></dt>
              <dd>A network protocol exposed by the device, where the
                attribute <code>type</code> can be "80203" for IEEE
                802.3, or "80211" for various flavors of IEEE 802.11.
              </dd>
            </dl>
          </dd>
          <dt><code>scsi_host</code></dt>
          <dd>Describes a SCSI host device.  Sub-elements include:
            <dl>
              <dt><code>host</code></dt>
              <dd>The SCSI host number.</dd>
              <dt><code>unique_id</code></dt>
              <dd>On input, this optionally provides the value from the
                'unique_id' file found in the scsi_host's directory. To
                view the values of all 'unique_id' files, use <code>find -H
                /sys/class/scsi_host/host{0..9}/unique_id |
                xargs grep '[0-9]'</code>. On output, if the unique_id
                file exists, the value from the file will be displayed.
                This can be used in order to help uniquely identify the
                scsi_host adapter in a <a href="formatstorage.html">
                Storage Pool</a>. <span class="since">Since 1.2.7</span>
              </dd>
              <dt><code>capability</code></dt>
              <dd>Current capabilities include "vports_ops" (indicates
                vport operations are supported) and "fc_host". "vport_ops"
                could contain two optional sub-elements: <code>vports</code>,
                and <code>max_vports</code>. <code>vports</code> shows the
                number of vport in use. <code>max_vports</code> shows the
                maximum vports the HBA supports. "fc_host" implies following
                sub-elements: <code>wwnn</code>, <code>wwpn</code>, and
                <code>fabric_wwn</code>.
              </dd>
            </dl>
          </dd>
          <dt><code>scsi</code></dt>
          <dd>Describes a SCSI device.  Sub-elements include:
            <dl>
              <dt><code>host</code></dt>
              <dd>The SCSI host containing the device.</dd>
              <dt><code>bus</code></dt>
              <dd>The bus within the host.</dd>
              <dt><code>target</code></dt>
              <dd>The target within the bus.</dd>
              <dt><code>lun</code></dt>
              <dd>The lun within the target.</dd>
              <dt><code>type</code></dt>
              <dd>The type of SCSI device.</dd>
            </dl>
          </dd>
          <dt><code>storage</code></dt>
          <dd>Describes a device usable for storage.  Sub-elements
            include:
            <dl>
              <dt><code>block</code></dt>
              <dd>A block device file name that accesses the storage
                present on the device.</dd>
              <dt><code>bus</code></dt>
              <dd>If present, the name of the bus the device is found
                on.</dd>
              <dt><code>drive_type</code></dt>
              <dd>The type of the drive, such as "disk" or
                "cdrom".</dd>
              <dt><code>model</code></dt>
              <dd>Any model information available from the
                device.</dd>
              <dt><code>vendor</code></dt>
              <dd>Any vendor information available from the
                device.</dd>
              <dt><code>serial</code></dt>
              <dd>Any serial number information available from the
                device.</dd>
              <dt><code>size</code></dt>
              <dd>For fixed-size storage, the amount of storage
                available.</dd>
              <dt><code>capability</code></dt>
              <dd>If present, an additional capability is listed via
                the attribute <code>type</code>.  Current capabilities
                include "hotpluggable" and "removable", with the
                latter implying the following
                sub-elements: <code>media_available</code> (0 or
                1), <code>media_size</code>,
                and <code>media_label</code>.</dd>
            </dl>
          </dd>
        </dl>
      </dd>
    </dl>

    <h2><a name="nodeExample">Examples</a></h2>

    <p>The following are some example node device XML outputs:</p>
    <pre>
&lt;device&gt;
  &lt;name&gt;computer&lt;/name&gt;
  &lt;capability type='system'&gt;
    &lt;product&gt;2241B36&lt;/product&gt;
    &lt;hardware&gt;
      &lt;vendor&gt;LENOVO&lt;/vendor&gt;
      &lt;version&gt;ThinkPad T500&lt;/version&gt;
      &lt;serial&gt;R89055N&lt;/serial&gt;
      &lt;uuid&gt;c9488981-5049-11cb-9c1c-993d0230b4cd&lt;/uuid&gt;
    &lt;/hardware&gt;
    &lt;firmware&gt;
      &lt;vendor&gt;LENOVO&lt;/vendor&gt;
      &lt;version&gt;6FET82WW (3.12 )&lt;/version&gt;
      &lt;release_date&gt;11/26/2009&lt;/release_date&gt;
    &lt;/firmware&gt;
  &lt;/capability&gt;
&lt;/device&gt;

&lt;device&gt;
  &lt;name&gt;net_eth1_00_27_13_6a_fe_00&lt;/name&gt;
  &lt;parent&gt;pci_0000_00_19_0&lt;/parent&gt;
  &lt;capability type='net'&gt;
    &lt;interface&gt;eth1&lt;/interface&gt;
    &lt;address&gt;00:27:13:6a:fe:00&lt;/address&gt;
    &lt;capability type='80203'/&gt;
  &lt;/capability&gt;
&lt;/device&gt;

&lt;device&gt;
  &lt;name&gt;pci_0000_02_00_0&lt;/name&gt;
  &lt;path&gt;/sys/devices/pci0000:00/0000:00:04.0/0000:02:00.0&lt;/path&gt;
  &lt;parent&gt;pci_0000_00_04_0&lt;/parent&gt;
  &lt;driver&gt;
    &lt;name&gt;igb&lt;/name&gt;
  &lt;/driver&gt;
  &lt;capability type='pci'&gt;
    &lt;domain&gt;0&lt;/domain&gt;
    &lt;bus&gt;2&lt;/bus&gt;
    &lt;slot&gt;0&lt;/slot&gt;
    &lt;function&gt;0&lt;/function&gt;
    &lt;product id='0x10c9'&gt;82576 Gigabit Network Connection&lt;/product&gt;
    &lt;vendor id='0x8086'&gt;Intel Corporation&lt;/vendor&gt;
    &lt;capability type='virt_functions'&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x10' function='0x0'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x10' function='0x2'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x10' function='0x4'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x10' function='0x6'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x11' function='0x0'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x11' function='0x2'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x11' function='0x4'/&gt;
    &lt;/capability&gt;
    &lt;iommuGroup number='12'&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x00' function='0x0'/&gt;
      &lt;address domain='0x0000' bus='0x02' slot='0x00' function='0x1'/&gt;
    &lt;/iommuGroup&gt;
    &lt;pci-express&gt;
      &lt;link validity='cap' port='1' speed='2.5' width='1'/&gt;
      &lt;link validity='sta' speed='2.5' width='1'/&gt;
    &lt;/pci-express&gt;
  &lt;/capability&gt;
&lt;/device&gt;
    </pre>

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