monitor: an interface of acrn-dm

A monitor component will be added to acrn-dm, which crteats socket,
bind and listening at /run/acrn/vmname. Acrnctl & acrnd could conn
-ect to the socket for communication, using defined message, in
include/monitor_msg.h
For each defined message, a message handler callback could be
registered via monitor_add_msg_handler(). On received of a defined
message, a certain call back will be called. Each callback can only
see the message sender's socket-fd.
When acrn-dm want report something, not triggered by incoming message
it can send broadcast message, use monitor_broadcast().

Acked-by: Eddie Dong <eddie.dong@intel.com>
Reviewed-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Yin, Fengwei <fengwei.yin@intel.com>
Signed-off-by: Tao, Yuhong <yuhong.tao@intel.com>

devicemodel/include/monitor.h

@@ -0,0 +1,82 @@
+/*
+ * Project Acrn
+ * Acrn-dm-monitor
+ *
+ * Copyright (C) 2018 Intel Corporation. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *
+ * Author: TaoYuhong <yuhong.tao@intel.com>
+ */
+
+/* acrn-dm monitor APIS */
+
+#ifndef MONITOR_H
+#define MONITOR_H
+
+#include "monitor_msg.h"
+
+int monitor_init(struct vmctx *ctx);
+void monitor_close(void);
+
+/**
+ * monitor broadcast()
+ * Developer can use monitor_broadcast() inside acrn-dm, send vmm_msg to all client.
+ * @arguements:
+ * @msg: any valid vmm_msg data structure, which you want send
+ */
+
+int monitor_broadcast(struct vmm_msg *msg);
+
+/* msg_sender will be seen/modify by msg handler */
+struct msg_sender {
+	int fd;			/* msg handler can replay to this fd */
+	char name[CLIENT_NAME_LEN];	/* client have a chance to name itsself */
+	int broadcast;
+};
+
+/**
+ * monitor_register_handler()
+ * Developer can add vmm_msg handler inside acrn-dm, that means, when a client send a
+ * vmm_msg to acrn-dm, the correspoding callback will be called
+ * @arguements:
+ * @msg: msg->msgid must be set, for which handler will be add.
+ * @callback: when a received message match msg->msgid, callback will be envoked.
+ *   And these data are pass in to help developer: (a)msg, the received message, from
+ *   socket. (b)sender, tell you who send this message, anything wite to sender->fd
+ *   will be able to read out by client socket. Developer should only write valid
+ *   vmm_msg. (c)priv, that is what you pass to monitor_add_msg_handler();
+ * @priv, callback will see this value.
+*/
+
+int monitor_register_handler(struct vmm_msg *msg,
+			     void (*callback) (struct vmm_msg * msg,
+					       struct msg_sender * sender,
+					       void *priv), void *priv);
+#endif