<capability>

Categorizes host devices according to the resources they can provide to a virtual server and describes these resources.

Text content

None.

Selected attributes

Categorizes the host device. The child elements that are used to describe the host resources depend on the type.

ap_card: Categorizes the host device as a cryptographic adapter.
ap_queue: Categorizes the host device as an AP queue, which corresponds to a domain on a cryptographic adapter.
ap_matrix: Categorizes the host device as a matrix of AP queues.
ccw: Categorizes the host device as a z/Architecture® CCW device.
css: Categorizes the host device as a subchannel of the z/Architecture channel subsystem (CSS).
mdev: Categorizes the host device as a VFIO mediated device.
mdev_types: Categorizes the host device as a potential parent of a VFIO mediated device in the libvirt hierarchy of host devices.

The values for the type attribute can be used for the --cap parameter of the nodedev-list command to filter the command output by resource type.

Usage

Managing mediated devices with libvirt

Parent elements

<device> as a root element
<capability>

Child elements

Depend on the capability type.

ap_card

<ap-adapter>

ap_queue

ap_matrix

<capability>
Note: <capability> as a child element of <capability> always is of type mdev_types.

ccw

<cssid>
<ssid>
<devno>

css

<cssid>
<ssid>
<devno>
<capability>

Note: <capability> as a child element of <capability> always is of type mdev_types.

mdev

<attr>
<iommuGroup>
<type>
<uuid>

mdev_types

<type>

Examples

This example shows the capabilities of a CSS subchannel.

<device>
    <name>css_0_0_0071</name>
    ...
    <capability type="css">
        <cssid>0x0</cssid> 
        <ssid>0x0</ssid>
        <devno>0x0071</devno>
     </capability>
     ...
</device>

This example shows the capabilities of a VFIO mediated device.

<device>
    <name>mdev_96c03c6a_a109_44fe_816a_ba371542164b_0_0_0072</name>
    ...
    <capability type="mdev">
        <type id=’vfio_ccw-io’/>
        <iommuGroup number=’1’/>
    </capability>
</device>

This example shows the capabilities of the ap_matrix host device. In the libvirty host-device hierarchy, this device is the common parent for AP mediated devices. It describes common properties for AP mediated devices.

<device>
    <name>ap_matrix</name>
    ...
    <capability type="ap_matrix">
        <capability type="mdev_types’">
            <type id="vfio_ap-passthrough">
                <name>VFIO AP Passthrough Device</name>
                <deviceAPI>vfio-ap</deviceAPI>
                <availableInstances>65534</availableInstances>
            </type>
        </capability>
    </capability>
</device>