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authorcornelia.huck <cornelia.huck@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652>2014-02-13 09:55:30 +0000
committercornelia.huck <cornelia.huck@0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652>2014-02-13 09:55:30 +0000
commit1da6ff099ef26e189229e493c28383e293fc0d39 (patch)
treee22f26064bd1f30dd6865bd101842bfc085c0e30 /content.tex
parented5fcb75d027a1e84223fd0fe9363d70f45bf230 (diff)
ccw: padding annotations
Remove __packed__ annotation from all ccw structures that don't need it, and make the length requirements explicit for those that do. This is the part of the patch to resolve VIRTIO-56 that had been missed. Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio@249 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652
Diffstat (limited to 'content.tex')
-rw-r--r--content.tex14
1 files changed, 9 insertions, 5 deletions
diff --git a/content.tex b/content.tex
index 0aed373..7e112c7 100644
--- a/content.tex
+++ b/content.tex
@@ -2107,7 +2107,7 @@ about a queue. It uses the following structure for communicating:
struct vq_config_block {
be16 index;
be16 max_num;
-} __attribute__ ((packed));
+};
\end{lstlisting}
The requested number of buffers for queue \field{index} is returned in
@@ -2125,7 +2125,7 @@ struct vq_info_block {
be16 num;
be64 avail;
be64 used;
-} __attribute__ ((packed));
+};
\end{lstlisting}
\field{desc}, \field{avail} and \field{used} contain the guest addresses for the descriptor table,
@@ -2144,7 +2144,7 @@ struct vq_info_block_legacy {
be32 align;
be16 index;
be16 num;
-} __attribute__ ((packed));
+};
\end{lstlisting}
\field{queue} contains the guest address for queue \field{index}, \field{num} the number of buffers
@@ -2192,12 +2192,13 @@ communication block:
struct virtio_feature_desc {
le32 features;
u8 index;
-} __attribute__ ((packed));
+};
\end{lstlisting}
\field{features} are the 32 bits of features currently accessed, while
\field{index} describes which of the feature bit values is to be
-accessed.
+accessed. No padding is added at the end of the structure, it is
+exactly 5 bytes in length.
The guest obtains the device's device feature set via the
CCW_CMD_READ_FEAT command. The device stores the features at \field{index}
@@ -2293,6 +2294,9 @@ significant bit in the first byte is assigned the bit number 0.
\field{isc} contains the I/O interruption subclass to be used for the adapter
I/O interrupt. It MAY be different from the isc used by the proxy
virtio-ccw device's subchannel.
+No padding is added at the end of the structure, it is exactly 25 bytes
+in length.
+
If the driver has already set up classic queue indicators via the
CCW_CMD_SET_IND command, the device MUST post a unit check with