Re: [PATCH v8 7/9] ccw: document ADMIN_VQ as reserved

[Cornelia Huck <cohuck@redhat.com>]

On Sun, Nov 20 2022, "Michael S. Tsirkin" <mst@redhat.com> wrote:

> Adding relevant registers needs more work and it's not
> clear what the use-case will be as currently only
> the PCI transport is supported. But let's keep the
> door open on this.
> We already say it's reserved in a central place, but it
> does not hurt to remind implementers to mask it.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  content.tex | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/content.tex b/content.tex
> index 9c74fa9..7111929 100644
> --- a/content.tex
> +++ b/content.tex
> @@ -2971,6 +2971,18 @@ \subsubsection{Resetting Devices}\label{sec:Virtio Transport Options / Virtio ov
>  MAY also choose to verify reset completion by reading \field{device status} via
>  CCW_CMD_READ_STATUS and checking whether it is 0 afterwards.
>  
> +\subsection{Features reserved for future use}\label{sec:Virtio Transport Options / Virtio Over MMIO / Features reserved for future use}

s/MMIO/Channel I/O/

> +
> +At this time, devices and drivers utilizing Virtio over channel I/O
> +do not support the following features:
> +\begin{itemize}
> +
> +\item VIRTIO_F_ADMIN_VQ

There are already a few features not yet supported for ccw (queue reset,
shared memory, ...) -- would it make sense to add a separate patch
listing all of the features not yet supported prior to adding all of the
admin vq infrastructure? Otherwise, this section is a bit misleading.

(What is the situation for MMIO?)

> +
> +\end{itemize}
> +
> +These features are reserved for future use.
> +
>  \chapter{Device Types}\label{sec:Device Types}
>  
>  On top of the queues, config space and feature negotiation facilities