On Tue, 8 Oct 2013 15:39:25 +0200
Cornelia Huck <> wrote:
> On Tue, 8 Oct 2013 16:07:18 +0300
> "Michael S. Tsirkin" <> wrote:
> > If we want drivers to do something we really must write it
> > explicitly.
> >
>
OK, here's what I've got:
commit 5a36ad2c5826ccf777d12b2183efc265c51015b0
Author: Cornelia Huck <>
Date: Tue Oct 8 15:49:36 2013 +0200
virtio-ccw: clarify sense id operation
Signed-off-by: Cornelia Huck <>
diff --git a/virtio-v1.0-wd01-part1-specification.txt b/virtio-v1.0-wd01-part1-specification.txt
index d1b15c6..4eb770e 100644
--- a/virtio-v1.0-wd01-part1-specification.txt
+++ b/virtio-v1.0-wd01-part1-specification.txt
@@ -1515,6 +1515,28 @@ normal channel subsystem device discovery (usually a STORE
SUBCHANNEL loop) and answers to the basic channel commands, most
importantly SENSE ID.
+For a virtio-ccw proxy device, SENSE ID will return the following
+information:
+
+------------------------------------------------------
+| Bytes | Contents |
+|-------|--------------------------------------------|
+| 0 | reserved | 0xff |
+|-------|-----------------------|--------------------|
+| 1-2 | control unit type | 0x3832 |
+|-------|-----------------------|--------------------|
+| 3 | control unit model | <virtio device id> |
+|-------|-----------------------|--------------------|
+| 4-5 | device type | zeroes (unset) |
+|-------|-----------------------|--------------------|
+| 6 | device model | zeroes (unset) |
+|-------|-----------------------|--------------------|
+| 7-255 | extended SenseId data | zeroes (unset) |
+------------------------------------------------------
+
+A driver for virtio-ccw devices MUST check for a control unit
+type of 0x3832 and MUST ignore the device type and model.
+
In addition to the basic channel commands, virtio-ccw defines a
set of channel commands related to configuration and operation of
virtio:
