[PATCH 3/5] virtqueue: constraints for virtqueue state

[Zhu Lingshan <lingshan.zhu@intel.com>]

This commit specifies the constraints of the virtqueue state,
and the actions should be taken by the device when SUSPEND
and DRIVER_OK is set

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eugenio PÃrez <eperezma@redhat.com>
---
 content.tex | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/content.tex b/content.tex
index 0fab537..9d727ce 100644
--- a/content.tex
+++ b/content.tex
@@ -594,6 +594,25 @@ \subsection{\field{Used State} Field}
 When VIRTIO_RING_F_PACKED is not negotiated, the 16-bit value of \field{used_idx}
 is always 0
 
+\drivernormative{\subsection}{Virtqueue State}{Basic Facilities of a Virtio Device / Virtqueue State}
+
+If VIRTIO_F_QUEUE_STATE has been negotiated but VIRTIO_RING_F_PACKED not been negotiated,
+the driver SHOULD NOT access \field{Used State} of any virtqueues, it SHOULD use the
+used index in the used ring.
+
+\devicenormative{\subsection}{Virtqueue State}{Basic Facilities of a Virtio Device / Virtqueue State}
+
+If VIRTIO_F_QUEUE_STATE has been negotiated, the device SHOULD only accept setting
+Virtqueue State of any virtqueues when DRIVER_OK is not set in \field{device status},
+or both of DRIVER_OK and SUSPEND are set in \field{device status}.
+Otherwise the device MUST ignore any writes to Virtqueue State of any virtqueues.
+
+If VIRTIO_F_QUEUE_STATE have been negotiated, when SUSPEND is set,
+the device MUST record the Virtqueue State of every enabled virtqueue
+in \field{Available State} and \field{Used State} respectively,
+and correspondingly restore the Virtqueue State of every enabled virtqueue
+from \field{Available State} and \field{Used State} when DRIVER_OK is set.
+
 \input{admin.tex}
 
 \chapter{General Initialization And Device Operation}\label{sec:General Initialization And Device Operation}
-- 
2.35.3