libvhost-user: make it a meson subproject

By making libvhost-user a subproject, check it builds
standalone (without the global QEMU cflags etc).

Note that the library still relies on QEMU include/qemu/atomic.h and
linux_headers/.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20201125100640.366523-6-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

subprojects/libvhost-user/libvhost-user-glib.h

@@ -0,0 +1,36 @@
+/*
+ * Vhost User library
+ *
+ * Copyright (c) 2016 Nutanix Inc. All rights reserved.
+ * Copyright (c) 2017 Red Hat, Inc.
+ *
+ * Authors:
+ *  Marc-André Lureau <mlureau@redhat.com>
+ *  Felipe Franciosi <felipe@nutanix.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or
+ * later.  See the COPYING file in the top-level directory.
+ */
+
+#ifndef LIBVHOST_USER_GLIB_H
+#define LIBVHOST_USER_GLIB_H
+
+#include <glib.h>
+#include "libvhost-user.h"
+
+typedef struct VugDev {
+    VuDev parent;
+
+    GHashTable *fdmap; /* fd -> gsource */
+    GSource *src;
+} VugDev;
+
+bool vug_init(VugDev *dev, uint16_t max_queues, int socket,
+              vu_panic_cb panic, const VuDevIface *iface);
+void vug_deinit(VugDev *dev);
+
+GSource *vug_source_new(VugDev *dev, int fd, GIOCondition cond,
+                        vu_watch_cb vu_cb, gpointer data);
+void vug_source_destroy(GSource *src);
+
+#endif /* LIBVHOST_USER_GLIB_H */