hyper-v: trace vmbus_onoffer_rescind()

Add tracepoint to CHANNELMSG_RESCIND_CHANNELOFFER handler.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hv/channel_mgmt.c

@@ -856,6 +856,8 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 
 	rescind = (struct vmbus_channel_rescind_offer *)hdr;
 
+	trace_vmbus_onoffer_rescind(rescind);
+
 	/*
 	 * The offer msg and the corresponding rescind msg
 	 * from the host are guranteed to be ordered -

drivers/hv/hv_trace.h

@@ -61,6 +61,14 @@ TRACE_EVENT(vmbus_onoffer,
 		    )
 	);
 
+TRACE_EVENT(vmbus_onoffer_rescind,
+	    TP_PROTO(const struct vmbus_channel_rescind_offer *offer),
+	    TP_ARGS(offer),
+	    TP_STRUCT__entry(__field(u32, child_relid)),
+	    TP_fast_assign(__entry->child_relid = offer->child_relid),
+	    TP_printk("child_relid 0x%x", __entry->child_relid)
+	);
+
 #undef TRACE_INCLUDE_PATH
 #define TRACE_INCLUDE_PATH .
 #undef TRACE_INCLUDE_FILE