[libvirt PATCH] docs: Rephrase the video 'none' type to clarify the reasoning

[Michal Privoznik]

On 9/8/20 11:59 AM, Erik Skultety wrote:
> Signed-off-by: Erik Skultety <eskultet at redhat.com>
> ---
>   docs/formatdomain.rst | 17 ++++++++++-------
>   1 file changed, 10 insertions(+), 7 deletions(-)
> 
> This is a tiny follow-up improvement resulting from [1] as I felt the paragraph
> wasn't clear enough + there were a couple of typographical issues.
> [1] https://www.redhat.com/archives/libvir-list/2020-September/msg00329.html
> 
> diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst
> index 1979dfb8d3..cf3ccbecc5 100644
> --- a/docs/formatdomain.rst
> +++ b/docs/formatdomain.rst
> @@ -5784,13 +5784,16 @@ A video device.
>      value "vga", "cirrus", "vmvga", "xen", "vbox", "qxl" ( :since:`since 0.8.6`
>      ), "virtio" ( :since:`since 1.3.0` ), "gop" ( :since:`since 3.2.0` ), "bochs"
>      ( :since:`since 5.6.0` ), "ramfb" ( :since:`since 5.9.0` ), or "none" (
> -   :since:`since 4.6.0` , depending on the hypervisor features available. The
> -   purpose of the type ``none`` is to instruct libvirt not to add a default
> -   video device in the guest (see the paragraph above). This legacy behaviour
> -   can be inconvenient in cases where GPU mediated devices are meant to be the
> -   only rendering device within a guest and so specifying another ``video``
> -   device along with type ``none``. Refer to Host device assignment to see how
> -   to add a mediated device into a guest.
> +   :since:`since 4.6.0`) , depending on the hypervisor features available.

Looks like we like an extra space before ')' in this paragraph.

> +
> +   Note: The purpose of the type ``none`` is to instruct libvirt not to add a
> +   default video device in the guest (see the ``video`` element description
> +   above), since such behaviour is inconvenient in cases where GPU mediated
> +   devices are meant to be the only rendering device within a guest. If this
> +   is your use case specify a ``none`` type ``video`` device in the XML to stop
> +   the default behaviour. Refer to `Host device assignment
> +   <#host-device-assignment>`__ to see how to add a mediated device into a
> +   guest.
> 
>      You can provide the amount of video memory in kibibytes (blocks of 1024
>      bytes) using ``vram``. This is supported only for guest type of "vz", "qemu",


Reviewed-by: Michal Privoznik <mprivozn at redhat.com>

Michal