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, 51 insertions, 0 deletions

diff --git a/stubs/trace-control.c b/stubs/trace-control.c
new file mode 100644
index 000000000..7f856e5c2
--- /dev/null
+++ b/stubs/trace-control.c
@@ -0,0 +1,51 @@
+/*
+ * Interface for configuring and controlling the state of tracing events.
+ *
+ * Copyright (C) 2014-2016 Lluís Vilanova <vilanova@ac.upc.edu>
+ *
+ * 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 "trace/control.h"
+
+
+void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
+{
+    trace_event_set_state_dynamic(ev, state);
+}
+
+void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
+{
+    bool state_pre;
+    assert(trace_event_get_state_static(ev));
+
+    /*
+     * We ignore the "vcpu" property here, since there's no target code. Then
+     * dstate can only be 1 or 0.
+     */
+    state_pre = *(ev->dstate);
+    if (state_pre != state) {
+        if (state) {
+            trace_events_enabled_count++;
+            *(ev->dstate) = 1;
+        } else {
+            trace_events_enabled_count--;
+            *(ev->dstate) = 0;
+        }
+    }
+}
+
+void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
+                                        TraceEvent *ev, bool state)
+{
+    /* should never be called on non-target binaries */
+    abort();
+}
+
+void trace_init_vcpu(CPUState *vcpu)
+{
+    /* should never be called on non-target binaries */
+    abort();
+}