summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authormstsirkin <mstsirkin@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652>2014-03-02 21:35:56 +0000
committermstsirkin <mstsirkin@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652>2014-03-02 21:35:56 +0000
commit53b9bba9fc087489b4ffdd0aa37eb802a6c22693 (patch)
tree5e33b92166e57b93ffd27989872e36a93a701cfc
parentc560b6f289f54b15538fcfa43e8b6500dae6159d (diff)
legacy virtqueue layout: confirmance
Change accepted on VIRTIO TC Meeting, 3 December 2013 Signed-off-by: Michael S. Tsirkin <mst@redhat.com> git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@298 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652
-rw-r--r--content.tex10
1 files changed, 8 insertions, 2 deletions
diff --git a/content.tex b/content.tex
index 9276d9b..75e80b5 100644
--- a/content.tex
+++ b/content.tex
@@ -318,7 +318,11 @@ Descriptor Table & Available Ring (\ldots padding\ldots) & Used Ring \\
\end{tabular}
The bus-specific Queue Size field controls the total number of bytes
-required for the virtqueue according to the following formula:
+required for the virtqueue.
+When using the legacy interface, the transitional
+driver MUST retrieve the Queue Size field from the device
+and MUST allocate the total number of bytes for the virtuqueue
+according to the following formula:
\begin{lstlisting}
#define ALIGN(x) (((x) + PAGE_SIZE) & ~PAGE_SIZE)
@@ -330,7 +334,9 @@ static inline unsigned vring_size(unsigned int qsz)
\end{lstlisting}
This wastes some space with padding.
-The legacy virtqueue layout structure therefore looks like this:
+When using the legacy interface, both transitional
+devices and drivers MUST use the following virtqueue layout
+structure to locate elements of the virtqueue:
\begin{lstlisting}
struct vring {