2 files changed, 41 insertions, 1 deletions
diff --git a/util/Makefile.objs b/util/Makefile.objs
index 3fb611631f..ae90b9963d 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -1,7 +1,7 @@
 util-obj-y = osdep.o cutils.o unicode.o qemu-timer-common.o
 util-obj-y += bufferiszero.o
 util-obj-y += lockcnt.o
-util-obj-y += aiocb.o async.o thread-pool.o qemu-timer.o
+util-obj-y += aiocb.o async.o aio-wait.o thread-pool.o qemu-timer.o
 util-obj-y += main-loop.o iohandler.o
 util-obj-$(CONFIG_POSIX) += aio-posix.o
 util-obj-$(CONFIG_POSIX) += compatfd.o
diff --git a/util/aio-wait.c b/util/aio-wait.c
new file mode 100644
index 0000000000..a487cdb852
--- /dev/null
+++ b/util/aio-wait.c
@@ -0,0 +1,40 @@
+/*
+ * AioContext wait support
+ *
+ * Copyright (C) 2018 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "block/aio-wait.h"
+
+static void dummy_bh_cb(void *opaque)
+{
+    /* The point is to make AIO_WAIT_WHILE()'s aio_poll() return */
+}
+
+void aio_wait_kick(AioWait *wait)
+{
+    /* The barrier (or an atomic op) is in the caller.  */
+    if (atomic_read(&wait->need_kick)) {
+        aio_bh_schedule_oneshot(qemu_get_aio_context(), dummy_bh_cb, NULL);
+    }
+}