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authorMichael S. Tsirkin <mst@redhat.com>2018-03-09 23:23:34 +0200
committerMichael S. Tsirkin <mst@redhat.com>2018-03-20 02:29:10 +0200
commit619a2785480f3275767b81a02cead33aaba4e801 (patch)
tree8f08fb037b5301e4b685541c7fbf9393039ae3a3
parent323f8193da1c07cdea4677b92b7658f650554ffe (diff)
split-ring: generalize text
Update generic text to talk about available/used buffers, not rings. Move some split-ring specific text to the correct section. Update conformance section with link to the new conformance clause. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Approved-by: https://www.oasis-open.org/apps/org/workgroup/virtio/ballot.php?id=3177 Fixes: https://github.com/oasis-tcs/virtio-spec/issues/3
-rw-r--r--conformance.tex1
-rw-r--r--content.tex10
-rw-r--r--split-ring.tex4
3 files changed, 9 insertions, 6 deletions
diff --git a/conformance.tex b/conformance.tex
index 55d17b4..e4efe33 100644
--- a/conformance.tex
+++ b/conformance.tex
@@ -38,6 +38,7 @@ A driver MUST conform to the following normative statements:
\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / The Virtqueue Descriptor Table}
\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / The Virtqueue Descriptor Table / Indirect Descriptors}
\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Interrupt Suppression}
+\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / The Virtqueue Available Ring}
\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / The Virtqueue Used Ring}
\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Notification Suppression}
\item \ref{drivernormative:Basic Facilities of a Virtio Device / Virtqueues / Supplying Buffers to The Device / Updating idx}
diff --git a/content.tex b/content.tex
index 60f51bb..c577133 100644
--- a/content.tex
+++ b/content.tex
@@ -381,12 +381,10 @@ of a device are live once the device has been reset.
\drivernormative{\subsection}{Device Cleanup}{General Initialization And Device Operation / Device Cleanup}
-A driver MUST NOT alter descriptor table entries which have been
-exposed in the available ring (and not marked consumed by the device
-in the used ring) of a live virtqueue.
-
-A driver MUST NOT decrement the available \field{idx} on a live virtqueue (ie.
-there is no way to ``unexpose'' buffers).
+A driver MUST NOT alter virtqueue entries for exposed buffers -
+i.e. buffers which have been
+made available to the device (and not been used by the device)
+of a live virtqueue.
Thus a driver MUST ensure a virtqueue isn't live (by device reset) before removing exposed buffers.
diff --git a/split-ring.tex b/split-ring.tex
index 9601a53..a594d41 100644
--- a/split-ring.tex
+++ b/split-ring.tex
@@ -296,6 +296,10 @@ referred to this structure as vring_avail, and the constant as
VRING_AVAIL_F_NO_INTERRUPT, but the layout and value were identical.
\end{note}
+\drivernormative{\subsubsection}{The Virtqueue Available Ring}{Basic Facilities of a Virtio Device / Virtqueues / The Virtqueue Available Ring}
+A driver MUST NOT decrement the available \field{idx} on a virtqueue (ie.
+there is no way to ``unexpose'' buffers).
+
\subsection{Virtqueue Interrupt Suppression}\label{sec:Basic Facilities of a Virtio Device / Virtqueues / Virtqueue Interrupt Suppression}
If the VIRTIO_F_EVENT_IDX feature bit is not negotiated,