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, 70 insertions, 0 deletions

diff --git a/util/qemu-print.c b/util/qemu-print.c
new file mode 100644
index 000000000..69ba612f5
--- /dev/null
+++ b/util/qemu-print.c
@@ -0,0 +1,70 @@
+/*
+ * Print to stream or current monitor
+ *
+ * Copyright (C) 2019 Red Hat Inc.
+ *
+ * Authors:
+ *  Markus Armbruster <armbru@redhat.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.
+ */
+
+#include "qemu/osdep.h"
+#include "monitor/monitor.h"
+#include "qemu/qemu-print.h"
+
+/*
+ * Print like vprintf().
+ * Print to current monitor if we have one, else to stdout.
+ */
+int qemu_vprintf(const char *fmt, va_list ap)
+{
+    Monitor *cur_mon = monitor_cur();
+    if (cur_mon) {
+        return monitor_vprintf(cur_mon, fmt, ap);
+    }
+    return vprintf(fmt, ap);
+}
+
+/*
+ * Print like printf().
+ * Print to current monitor if we have one, else to stdout.
+ */
+int qemu_printf(const char *fmt, ...)
+{
+    va_list ap;
+    int ret;
+
+    va_start(ap, fmt);
+    ret = qemu_vprintf(fmt, ap);
+    va_end(ap);
+    return ret;
+}
+
+/*
+ * Print like vfprintf()
+ * Print to @stream if non-null, else to current monitor.
+ */
+int qemu_vfprintf(FILE *stream, const char *fmt, va_list ap)
+{
+    if (!stream) {
+        return monitor_vprintf(monitor_cur(), fmt, ap);
+    }
+    return vfprintf(stream, fmt, ap);
+}
+
+/*
+ * Print like fprintf().
+ * Print to @stream if non-null, else to current monitor.
+ */
+int qemu_fprintf(FILE *stream, const char *fmt, ...)
+{
+    va_list ap;
+    int ret;
+
+    va_start(ap, fmt);
+    ret = qemu_vfprintf(stream, fmt, ap);
+    va_end(ap);
+    return ret;
+}