Michael S. Tsirkin wrote:
I took a stub at documenting CMD and FLUSH request types in virtio
block. Christoph, could you look over this please?
I note that the interface seems full of warts to me,
this might be a first step to cleaning them.
One issue I struggled with especially is how type
field mixes bits and non-bit values. I ended up
simply defining all legal values, so that we have
CMD = 2, CMD_OUT = 3 and so on.
I also avoided instroducing inhdr/outhdr structures
that virtio blk driver in linux uses, I was concerned
that nesting tables will confuse the reader.
Comments welcome.
Signed-off-by: Michael S. Tsirkin m...@redhat.com
--
diff --git a/virtio-spec.lyx b/virtio-spec.lyx
index d16104a..ed35893 100644
--- a/virtio-spec.lyx
+++ b/virtio-spec.lyx
@@ -67,7 +67,11 @@ IBM Corporation
\end_layout
\begin_layout Standard
+
+\change_deleted 0 1266531118
FIXME: virtio block scsi passthrough section
+\change_unchanged
+
\end_layout
\begin_layout Standard
@@ -4376,7 +4380,7 @@ struct virtio_net_ctrl_mac {
The device can filter incoming packets by any number of destination MAC
addresses.
\begin_inset Foot
-status open
+status collapsed
\begin_layout Plain Layout
Since there are no guarentees, it can use a hash filter orsilently switch
@@ -4549,6 +4553,22 @@ blk_size
\end_inset
.
+\change_inserted 0 1266444580
+
+\end_layout
+
+\begin_layout Description
+
+\change_inserted 0 1266471229
+VIRTIO_BLK_F_SCSI (7) Device supports scsi packet commands.
+\end_layout
+
+\begin_layout Description
+
+\change_inserted 0 1266444605
+VIRTIO_BLK_F_FLUSH (9) Cache flush command support.
+\change_unchanged
+
\end_layout
\begin_layout Description
@@ -4700,17 +4720,25 @@ struct virtio_blk_req {
\begin_layout Plain Layout
+\change_deleted 0 1266472188
+
#define VIRTIO_BLK_T_IN 0
\end_layout
\begin_layout Plain Layout
+\change_deleted 0 1266472188
+
#define VIRTIO_BLK_T_OUT 1
\end_layout
\begin_layout Plain Layout
+\change_deleted 0 1266472188
+
#define VIRTIO_BLK_T_BARRIER 0x8000
+\change_unchanged
+
\end_layout
\begin_layout Plain Layout
@@ -4735,11 +4763,15 @@ struct virtio_blk_req {
\begin_layout Plain Layout
+\change_deleted 0 1266472204
+
#define VIRTIO_BLK_S_OK0
\end_layout
\begin_layout Plain Layout
+\change_deleted 0 1266472204
+
#define VIRTIO_BLK_S_IOERR 1
\end_layout
@@ -4759,32 +4791,481 @@ struct virtio_blk_req {
\end_layout
\begin_layout Standard
-The type of the request is either a read (VIRTIO_BLK_T_IN) or a write
(VIRTIO_BL
-K_T_OUT); the high bit indicates that this request acts as a barrier and
- that all preceeding requests must be complete before this one, and all
- following requests must not be started until this is complete.
+
+\change_inserted 0 1266472490
+If the device has VIRTIO_BLK_F_SCSI feature, it can also support scsi packet
+ command requests, each of these requests is of form:
+\begin_inset listings
+inline false
+status open
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472395
+
+struct virtio_scsi_pc_req {
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472375
+
+ u32 type;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472375
+
+ u32 ioprio;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266474298
+
+ u64 sector;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266474308
+
+char cmd[];
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266505809
+
+ char data[][512];
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266505825
+
+#define SCSI_SENSE_BUFFERSIZE 96
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266505848
+
+u8 sense[SCSI_SENSE_BUFFERSIZE];
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472969
+
+u32 errors;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472979
+
+u32 data_len;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472984
+
+u32 sense_len;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472987
+
+u32 residual;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472375
+
+ u8 status;
+\end_layout
+
+\begin_layout Plain Layout
+
+\change_inserted 0 1266472375
+
+};
+\end_layout
+
+\end_inset
+
+
+\change_unchanged
+
\end_layout
\begin_layout Standard
-The ioprio field is a hint about the relative priorities of requests to
- the device: higher numbers indicate more important requests.
+The
+\emph on
+type
+\emph default
+ of the request is either a read (VIRTIO_BLK_T_IN)
+\change_inserted 0 1266495815
+,
+\change_unchanged
+
