Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 76 insertions, 0 deletions

diff --git a/util/notify.c b/util/notify.c
new file mode 100644
index 000000000..76bab212a
--- /dev/null
+++ b/util/notify.c
@@ -0,0 +1,76 @@
+/*
+ * Notifier lists
+ *
+ * Copyright IBM, Corp. 2010
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/notify.h"
+
+void notifier_list_init(NotifierList *list)
+{
+    QLIST_INIT(&list->notifiers);
+}
+
+void notifier_list_add(NotifierList *list, Notifier *notifier)
+{
+    QLIST_INSERT_HEAD(&list->notifiers, notifier, node);
+}
+
+void notifier_remove(Notifier *notifier)
+{
+    QLIST_REMOVE(notifier, node);
+}
+
+void notifier_list_notify(NotifierList *list, void *data)
+{
+    Notifier *notifier, *next;
+
+    QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) {
+        notifier->notify(notifier, data);
+    }
+}
+
+bool notifier_list_empty(NotifierList *list)
+{
+    return QLIST_EMPTY(&list->notifiers);
+}
+
+void notifier_with_return_list_init(NotifierWithReturnList *list)
+{
+    QLIST_INIT(&list->notifiers);
+}
+
+void notifier_with_return_list_add(NotifierWithReturnList *list,
+                                   NotifierWithReturn *notifier)
+{
+    QLIST_INSERT_HEAD(&list->notifiers, notifier, node);
+}
+
+void notifier_with_return_remove(NotifierWithReturn *notifier)
+{
+    QLIST_REMOVE(notifier, node);
+}
+
+int notifier_with_return_list_notify(NotifierWithReturnList *list, void *data)
+{
+    NotifierWithReturn *notifier, *next;
+    int ret = 0;
+
+    QLIST_FOREACH_SAFE(notifier, &list->notifiers, node, next) {
+        ret = notifier->notify(notifier, data);
+        if (ret != 0) {
+            break;
+        }
+    }
+    return ret;
+}