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, 45 insertions, 0 deletions

diff --git a/scripts/tracetool/backend/ust.py b/scripts/tracetool/backend/ust.py
new file mode 100644
index 000000000..c857516f2
--- /dev/null
+++ b/scripts/tracetool/backend/ust.py
@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+
+"""
+LTTng User Space Tracing backend.
+"""
+
+__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2017, Lluís Vilanova <vilanova@ac.upc.edu>"
+__license__    = "GPL version 2 or (at your option) any later version"
+
+__maintainer__ = "Stefan Hajnoczi"
+__email__      = "stefanha@redhat.com"
+
+
+from tracetool import out
+
+
+PUBLIC = True
+
+
+def generate_h_begin(events, group):
+    header = 'trace-ust-' + group + '.h'
+    out('#include <lttng/tracepoint.h>',
+        '#include "%s"' % header,
+        '',
+        '/* tracepoint_enabled() was introduced in LTTng UST 2.7 */',
+        '#ifndef tracepoint_enabled',
+        '#define tracepoint_enabled(a, b) true',
+        '#endif',
+        '')
+
+
+def generate_h(event, group):
+    argnames = ", ".join(event.args.names())
+    if len(event.args) > 0:
+        argnames = ", " + argnames
+
+    out('    tracepoint(qemu, %(name)s%(tp_args)s);',
+        name=event.name,
+        tp_args=argnames)
+
+
+def generate_h_backend_dstate(event, group):
+    out('    tracepoint_enabled(qemu, %(name)s) || \\',
+        name=event.name)