COLO-compare: Add remote notification chardev handler frame

Add chardev handler to send notification to remote(current from Xen) colo-frame.

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/colo-compare.c

@@ -87,8 +87,10 @@ typedef struct CompareState {
     CharBackend chr_pri_in;
     CharBackend chr_sec_in;
     CharBackend chr_out;
+    CharBackend chr_notify_dev;
     SocketReadState pri_rs;
     SocketReadState sec_rs;
+    SocketReadState notify_rs;
     bool vnet_hdr;
 
     /*
@@ -745,6 +747,19 @@ static void compare_sec_chr_in(void *opaque, const uint8_t *buf, int size)
     }
 }
 
+static void compare_notify_chr(void *opaque, const uint8_t *buf, int size)
+{
+    CompareState *s = COLO_COMPARE(opaque);
+    int ret;
+
+    ret = net_fill_rstate(&s->notify_rs, buf, size);
+    if (ret == -1) {
+        qemu_chr_fe_set_handlers(&s->chr_notify_dev, NULL, NULL, NULL, NULL,
+                                 NULL, NULL, true);
+        error_report("colo-compare notify_dev error");
+    }
+}
+
 /*
  * Check old packet regularly so it can watch for any packets
  * that the secondary hasn't produced equivalents of.
@@ -832,6 +847,11 @@ static void colo_compare_iothread(CompareState *s)
     qemu_chr_fe_set_handlers(&s->chr_sec_in, compare_chr_can_read,
                              compare_sec_chr_in, NULL, NULL,
                              s, s->worker_context, true);
+    if (s->notify_dev) {
+        qemu_chr_fe_set_handlers(&s->chr_notify_dev, compare_chr_can_read,
+                                 compare_notify_chr, NULL, NULL,
+                                 s, s->worker_context, true);
+    }
 
     colo_compare_timer_init(s);
     s->event_bh = qemu_bh_new(colo_compare_handle_event, s);
@@ -943,6 +963,10 @@ static void compare_sec_rs_finalize(SocketReadState *sec_rs)
     }
 }
 
+static void compare_notify_rs_finalize(SocketReadState *notify_rs)
+{
+    /* Get Xen colo-frame's notify and handle the message */
+}
 
 /*
  * Return 0 is success.
@@ -1013,6 +1037,17 @@ static void colo_compare_complete(UserCreatable *uc, Error **errp)
     net_socket_rs_init(&s->pri_rs, compare_pri_rs_finalize, s->vnet_hdr);
     net_socket_rs_init(&s->sec_rs, compare_sec_rs_finalize, s->vnet_hdr);
 
+    /* Try to enable remote notify chardev, currently just for Xen COLO */
+    if (s->notify_dev) {
+        if (find_and_check_chardev(&chr, s->notify_dev, errp) ||
+            !qemu_chr_fe_init(&s->chr_notify_dev, chr, errp)) {
+            return;
+        }
+
+        net_socket_rs_init(&s->notify_rs, compare_notify_rs_finalize,
+                           s->vnet_hdr);
+    }
+
     QTAILQ_INSERT_TAIL(&net_compares, s, next);
 
     g_queue_init(&s->conn_list);
@@ -1091,6 +1126,10 @@ static void colo_compare_finalize(Object *obj)
     qemu_chr_fe_deinit(&s->chr_pri_in, false);
     qemu_chr_fe_deinit(&s->chr_sec_in, false);
     qemu_chr_fe_deinit(&s->chr_out, false);
+    if (s->notify_dev) {
+        qemu_chr_fe_deinit(&s->chr_notify_dev, false);
+    }
+
     if (s->iothread) {
         colo_compare_timer_del(s);
     }