Drivers: hv: vmbus: define a new VMBus message type for hvsock

A function to send the type of message is also added.

The coming net/hvsock driver will use this function to proactively request
the host to offer a VMBus channel for a new hvsock connection.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 3f04533..fcab234 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -219,6 +219,21 @@
 }
 EXPORT_SYMBOL_GPL(vmbus_open);
 
+/* Used for Hyper-V Socket: a guest client's connect() to the host */
+int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
+				  const uuid_le *shv_host_servie_id)
+{
+	struct vmbus_channel_tl_connect_request conn_msg;
+
+	memset(&conn_msg, 0, sizeof(conn_msg));
+	conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
+	conn_msg.guest_endpoint_id = *shv_guest_servie_id;
+	conn_msg.host_service_id = *shv_host_servie_id;
+
+	return vmbus_post_msg(&conn_msg, sizeof(conn_msg));
+}
+EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
+
 /*
  * create_gpadl_header - Creates a gpadl for the specified buffer
  */
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index d6c6114..60ca25b 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -958,6 +958,10 @@
 	{CHANNELMSG_VERSION_RESPONSE,		1, vmbus_onversion_response},
 	{CHANNELMSG_UNLOAD,			0, NULL},
 	{CHANNELMSG_UNLOAD_RESPONSE,		1, vmbus_unload_response},
+	{CHANNELMSG_18,				0, NULL},
+	{CHANNELMSG_19,				0, NULL},
+	{CHANNELMSG_20,				0, NULL},
+	{CHANNELMSG_TL_CONNECT_REQUEST,		0, NULL},
 };
 
 /*
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 79c4aa7..898eac9 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -392,6 +392,10 @@
 	CHANNELMSG_VERSION_RESPONSE		= 15,
 	CHANNELMSG_UNLOAD			= 16,
 	CHANNELMSG_UNLOAD_RESPONSE		= 17,
+	CHANNELMSG_18				= 18,
+	CHANNELMSG_19				= 19,
+	CHANNELMSG_20				= 20,
+	CHANNELMSG_TL_CONNECT_REQUEST		= 21,
 	CHANNELMSG_COUNT
 };
 
@@ -562,6 +566,13 @@
 	u64 monitor_page2;
 } __packed;
 
+/* Hyper-V socket: guest's connect()-ing to host */
+struct vmbus_channel_tl_connect_request {
+	struct vmbus_channel_message_header header;
+	uuid_le guest_endpoint_id;
+	uuid_le host_service_id;
+} __packed;
+
 struct vmbus_channel_version_response {
 	struct vmbus_channel_message_header header;
 	u8 version_supported;
@@ -1283,4 +1294,6 @@
 
 extern __u32 vmbus_proto_version;
 
+int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
+				  const uuid_le *shv_host_servie_id);
 #endif /* _HYPERV_H */