Node devices XML format
Node Device XML ¶
There are several libvirt functions, all with the
prefix virNodeDevice
, which deal with management of
host devices that can be handed to guests via passthrough as
<hostdev> elements
in the domain XML.
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".
When represented in XML, a node device uses the
top-level device
element, with the following
elements present according to the type of device:
name
- 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".
parent
- If this element is present, it names the parent device (that is, a controller to which this node belongs).
capability
- This node appears for each capability that libvirt
associates with a node. A mandatory
attribute
type
lists which category the device belongs to, and controls which further subelements will be present to describe the node:system
- Describes the overall host. Sub-elements include:
product
- If present, a simple text string giving the product name of the system.
hardware
- Describes the hardware of the system, including
sub-elements for
vendor
,version
,serial
, anduuid
. firmware
- Describes the firmware of the system, including
sub-elements for
vendor
,version
, andrelease_date
.
pci
- Describes a device on the host's PCI bus. Sub-elements
include:
domain
- Which domain the device belongs to.
bus
- Which bus within the domain.
slot
- Which slot within the bus.
function
- Which function within the slot.
product
- Product details from the device ROM, including an
attribute
id
with the hexadecimal product id, and an optional text description of that id. vendor
- Vendor details from the device ROM, including an
attribute
id
with the hexadecimal vendor id, and an optional text name of that vendor. iommuGroup
-
This optional element describes the "IOMMU group" this
device belongs to. If the element exists, it has a
mandatory
number
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 ofaddress
subelements, each containing the PCI address of a device in the same group. The toplevel device will itself be included in this list. capability
-
This optional element can occur multiple times. If it
exists, it has a mandatory
type
attribute which will be set to eitherphysical_function
orvirtual_functions
. If the type isphysical_function
, there will be a singleaddress
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 isvirtual_functions
, then this device is an SRIOV PF, and the capability element will have a list ofaddress
subelements, one for each VF on this PF.
usb_device
- Describes a device on the host's USB bus, based on its
location within the bus. Sub-elements include:
bus
- Which bus the device belongs to.
device
- Which device within the bus.
product
- Product details from the device ROM, including an
attribute
id
with the hexadecimal product id, and an optional text description of that id. vendor
- Vendor details from the device ROM, including an
attribute
id
with the hexadecimal vendor id, and an optional text name of that vendor.
usb
- Describes a USB device, based on its advertised driver
interface. Sub-elements include:
number
- The device number.
class
- The device class.
subclass
- The device subclass.
protocol
- The device protocol.
description
- If present, a description of the device.
net
- Describes a device capable for use as a network
interface. Sub-elements include:
interface
- The interface name tied to this device.
address
- If present, the MAC address of the device.
capability
- A network protocol exposed by the device, where the
attribute
type
can be "80203" for IEEE 802.3, or "80211" for various flavors of IEEE 802.11.
scsi_host
- Describes a SCSI host device. Sub-elements include:
host
- The SCSI host number.
capability
- Current capabilities include "vports_ops" (indicates
vport operations are supported) and "fc_host". "vport_ops"
could contain two optional sub-elements:
vports
, andmax_vports
.vports
shows the number of vport in use.max_vports
shows the maximum vports the HBA supports. "fc_host" implies following sub-elements:wwnn
,wwpn
, andfabric_wwn
.
scsi
- Describes a SCSI device. Sub-elements include:
host
- The SCSI host containing the device.
bus
- The bus within the host.
target
- The target within the bus.
lun
- The lun within the target.
type
- The type of SCSI device.
storage
- Describes a device usable for storage. Sub-elements
include:
block
- A block device file name that accesses the storage present on the device.
bus
- If present, the name of the bus the device is found on.
drive_type
- The type of the drive, such as "disk" or "cdrom".
model
- Any model information available from the device.
vendor
- Any vendor information available from the device.
serial
- Any serial number information available from the device.
size
- For fixed-size storage, the amount of storage available.
capability
- If present, an additional capability is listed via
the attribute
type
. Current capabilities include "hotpluggable" and "removable", with the latter implying the following sub-elements:media_available
(0 or 1),media_size
, andmedia_label
.
Examples ¶
The following are some example node device XML outputs:
<device> <name>computer</name> <capability type='system'> <product>2241B36</product> <hardware> <vendor>LENOVO</vendor> <version>ThinkPad T500</version> <serial>R89055N</serial> <uuid>c9488981-5049-11cb-9c1c-993d0230b4cd</uuid> </hardware> <firmware> <vendor>LENOVO</vendor> <version>6FET82WW (3.12 )</version> <release_date>11/26/2009</release_date> </firmware> </capability> </device> <device> <name>net_eth1_00_27_13_6a_fe_00</name> <parent>pci_0000_00_19_0</parent> <capability type='net'> <interface>eth1</interface> <address>00:27:13:6a:fe:00</address> <capability type='80203'/> </capability> </device> <device> <name>pci_0000_02_00_0</name> <path>/sys/devices/pci0000:00/0000:00:04.0/0000:02:00.0</path> <parent>pci_0000_00_04_0</parent> <driver> <name>igb</name> </driver> <capability type='pci'> <domain>0</domain> <bus>2</bus> <slot>0</slot> <function>0</function> <product id='0x10c9'>82576 Gigabit Network Connection</product> <vendor id='0x8086'>Intel Corporation</vendor> <capability type='virt_functions'> <address domain='0x0000' bus='0x02' slot='0x10' function='0x0'/> <address domain='0x0000' bus='0x02' slot='0x10' function='0x2'/> <address domain='0x0000' bus='0x02' slot='0x10' function='0x4'/> <address domain='0x0000' bus='0x02' slot='0x10' function='0x6'/> <address domain='0x0000' bus='0x02' slot='0x11' function='0x0'/> <address domain='0x0000' bus='0x02' slot='0x11' function='0x2'/> <address domain='0x0000' bus='0x02' slot='0x11' function='0x4'/> </capability> <iommuGroup number='12'> <address domain='0x0000' bus='0x02' slot='0x00' function='0x0'/> <address domain='0x0000' bus='0x02' slot='0x00' function='0x1'/> </iommuGroup> </capability> </device>