vmbus: add monitor_id and subchannel_id to sysfs per channel

Useful to identify which network queue is associated with
which vmbus channel.
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/stable/sysfs-bus-vmbus

@@ -118,3 +118,17 @@ KernelVersion:	4.14
 Contact:	Stephen Hemminger <sthemmin@microsoft.com>
 Description:	Number of times we have taken an interrupt (incoming)
 Users:		Debugging tools
+
+What:		/sys/bus/vmbus/devices/vmbus_*/channels/NN/subchannel_id
+Date:		January. 2018
+KernelVersion:	4.16
+Contact:	Stephen Hemminger <sthemmin@microsoft.com>
+Description:	Subchannel ID associated with VMBUS channel
+Users:		Debugging tools and userspace drivers
+
+What:		/sys/bus/vmbus/devices/vmbus_*/channels/NN/monitor_id
+Date:		January. 2018
+KernelVersion:	4.16
+Contact:	Stephen Hemminger <sthemmin@microsoft.com>
+Description:	Monitor bit associated with channel
+Users:		Debugging tools and userspace drivers

drivers/hv/vmbus_drv.c

@@ -1254,6 +1254,21 @@ static ssize_t channel_events_show(const struct vmbus_channel *channel, char *bu
 }
 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
 
+static ssize_t subchannel_monitor_id_show(const struct vmbus_channel *channel,
+					  char *buf)
+{
+	return sprintf(buf, "%u\n", channel->offermsg.monitorid);
+}
+static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
+
+static ssize_t subchannel_id_show(const struct vmbus_channel *channel,
+				  char *buf)
+{
+	return sprintf(buf, "%u\n",
+		       channel->offermsg.offer.sub_channel_index);
+}
+static VMBUS_CHAN_ATTR_RO(subchannel_id);
+
 static struct attribute *vmbus_chan_attrs[] = {
 	&chan_attr_out_mask.attr,
 	&chan_attr_in_mask.attr,
@@ -1264,6 +1279,8 @@ static struct attribute *vmbus_chan_attrs[] = {
 	&chan_attr_latency.attr,
 	&chan_attr_interrupts.attr,
 	&chan_attr_events.attr,
+	&chan_attr_monitor_id.attr,
+	&chan_attr_subchannel_id.attr,
 	NULL
 };