[PATCH 1/6] transport-mmio: Introduce administration virtqueues

[Parav Pandit <parav@nvidia.com>]

Administration virtqueues and group administration commands are
defined in a transport independent way, but so far only the PCI
transport describes how a device exposes administration virtqueues.

As the first step towards supporting them over MMIO, describe how
administration virtqueues fit into the MMIO transport: they are
regular virtqueues identified by an index, which are configured,
enabled, reset and notified like any other virtqueue, and which occupy
a contiguous range of indices beyond all other virtqueues.

Only the Self group type is applicable to the MMIO transport; state
this explicitly.

Subsequent patches add the registers to discover the administration
virtqueues and the related requirements.

Signed-off-by: Parav Pandit <parav@nvidia.com>
---
 transport-mmio.tex | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/transport-mmio.tex b/transport-mmio.tex
index cddbcc9..e015bd7 100644
--- a/transport-mmio.tex
+++ b/transport-mmio.tex
@@ -446,6 +446,27 @@ \subsubsection{Notifications From The Device}\label{sec:Virtio Transport Options
 it by writing a bit mask corresponding to the handled events to the
 InterruptACK register.
 
+\subsubsection{Administration Virtqueues}\label{sec:Virtio Transport Options / Virtio Over MMIO / MMIO-specific Initialization And Device Operation / Administration Virtqueues}
+
+A memory mapped virtio device can expose one or more administration
+virtqueues (see
+\ref{sec:Basic Facilities of a Virtio Device / Administration Virtqueues}~\nameref{sec:Basic Facilities of a Virtio Device / Administration Virtqueues}),
+which the driver uses to submit group administration commands (see
+\ref{sec:Basic Facilities of a Virtio Device / Device groups / Group administration commands}~\nameref{sec:Basic Facilities of a Virtio Device / Device groups / Group administration commands}).
+
+Only group administration commands of the Self group type are
+applicable to a memory mapped virtio device.
+
+An administration virtqueue is a virtqueue like any other: it is
+identified by its virtqueue index and
+the driver configures, enables, resets and notifies it using the same
+registers and procedures as for any other virtqueue of the device, see
+\ref{sec:Virtio Transport Options / Virtio Over MMIO / MMIO-specific Initialization And Device Operation / Virtqueue Configuration}~\nameref{sec:Virtio Transport Options / Virtio Over MMIO / MMIO-specific Initialization And Device Operation / Virtqueue Configuration}.
+
+The device reports a contiguous range of administration virtqueues.
+This range is located beyond the indices of all other virtqueues of
+the device.
+
 \subsection{Legacy interface}\label{sec:Virtio Transport Options / Virtio Over MMIO / Legacy interface}
 
 The legacy MMIO transport used page-based addressing, resulting
-- 
2.43.0