ccw: add CCW_CMD_READ_STATUS

ccw currently allows the driver to update the status via the
CCW_CMD_WRITE_STATUS command; however, it does not allow the driver to
retrieve the current status at the device, which is needed to properly
support DEVICE_NEEDS_RESET.

Therefore, provide a new command CCW_CMD_READ_STATUS allowing the driver
to retrieve the device status. Provide this command when revision 2 has
been negotiated.

VIRTIO-117

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <1445243513-2263-2-git-send-email-cornelia.huck@de.ibm.com>

git-svn-id: https://tools.oasis-open.org/version-control/svn/virtio/trunk@579 0c8fb4dd-22a2-4bb5-bc14-6c75a5f43652
1 file changed