---
features:
  - |
    When using XenAPI driver for XenServer, we can support booting instances
    with a vGPU attached to get better graphics processing capability.
    In order to use this feature, the operators should specify the enabled
    vGPU types in the nova compute configuration file with the configuration
    option - ``[devices]/enabled_vgpu_types``. Only the enabled vGPU types
    can be used by instances.

    XenServer automatically detects and groups together identical physical
    GPUs. Although the physical GPUs may support multiple vGPU types, at
    the moment nova only supports a single vGPU type for each compute node.
    The operators can run the following CLI commands in XenServer to get
    the available vGPU types if the host supports vGPU::

      xe vgpu-type-list

    The values of ``model-name ( RO):`` from the output of the above commands
    are the vGPU type names which you can choose from to set the nova
    configure - ``[devices]/enabled_vgpu_types``. Please choose only one
    vGPU type to be enabled.

    The operators should specify a vGPU resource in the flavor's extra_specs::

      nova flavor-key <flavor-id> set resources:VGPU=1

    Then users can use the flavor to boot instances with a vGPU attached.
    At the moment, XenServer doesn't support multiple vGPUs for a single
    instance, so ``resources:VGPU`` in the flavor's extra_specs should
    always be ``1``.
