Add virtio-loopback-adapter

The virtio-loopback-adapter is part of the Virtio Loopback
architecture detailed in the following link:
  https://git.virtualopensystems.com/virtio-loopback/docs

The following vhost-user devices are supported:
- vhost-user-blk
- vhost-user-rng
- vhost-user-input
- vhost-user-gpio
- vhost-user-sound

Bug-AGL: SPEC-4834
Change-Id: I4edb28faf370992f5f45390f5c4240a0f5c3084c
Signed-off-by: Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/event_notifier.h b/event_notifier.h
new file mode 100644
index 0000000..718f784
--- /dev/null
+++ b/event_notifier.h
@@ -0,0 +1,54 @@
+/*
+ * Based on event_notifier.h of QEMU project
+ *
+ *   Copyright Red Hat, Inc. 2010
+ *
+ *   Authors:
+ *    Michael S. Tsirkin <mst@redhat.com>
+ *
+ * Copyright 2023 Virtual Open Systems SAS.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+
+#ifndef EVENT_NOT_H
+#define EVENT_NOT_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <poll.h>
+#include <pthread.h>
+
+typedef struct EventNotifier {
+    int rfd;
+    int wfd;
+    bool initialized;
+} EventNotifier;
+
+
+int fcntl_setfl(int fd, int flag);
+void qemu_set_cloexec(int fd);
+int qemu_pipe(int pipefd[2]);
+int event_notifier_get_fd(const EventNotifier *e);
+int event_notifier_get_wfd(const EventNotifier *e);
+int event_notifier_set(EventNotifier *e);
+int event_notifier_init(EventNotifier *e, int active);
+bool ioeventfd_enabled(void);
+int event_notifier_test_and_clear(EventNotifier *e);
+
+
+#endif /* EVENT_NOT_H */