[PATCH v8 6/9] mmio: document ADMIN_VQ as reserved

["Michael S. Tsirkin" <mst@redhat.com>]

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 03cbd3f..9c74fa9 100644
--- a/content.tex
+++ b/content.tex
@@ -2357,6 +2357,18 @@ \subsection{Legacy interface}\label{sec:Virtio Transport Options / Virtio Over M
 
 Notification mechanisms did not change.
 
+\subsection{Features reserved for future use}\label{sec:Virtio Transport Options / Virtio Over MMIO / Features reserved for future use}
+
+At this time, devices and drivers utilizing Virtio Over MMIO
+do not support the following features:
+\begin{itemize}
+
+\item VIRTIO_F_ADMIN_VQ
+
+\end{itemize}
+
+These features are reserved for future use.
+
 \section{Virtio Over Channel I/O}\label{sec:Virtio Transport Options / Virtio Over Channel I/O}
 
 S/390 based virtual machines support neither PCI nor MMIO, so a
-- 
MST