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, 63 insertions, 0 deletions

diff --git a/trace/control-vcpu.h b/trace/control-vcpu.h
new file mode 100644
index 000000000..0f98ebe7b
--- /dev/null
+++ b/trace/control-vcpu.h
@@ -0,0 +1,63 @@
+/*
+ * Interface for configuring and controlling the state of tracing events.
+ *
+ * Copyright (C) 2011-2016 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.
+ */
+
+#ifndef TRACE__CONTROL_VCPU_H
+#define TRACE__CONTROL_VCPU_H
+
+#include "control.h"
+#include "event-internal.h"
+#include "hw/core/cpu.h"
+
+/**
+ * trace_event_get_vcpu_state:
+ * @vcpu: Target vCPU.
+ * @id: Event identifier name.
+ *
+ * Get the tracing state of an event (both static and dynamic) for the given
+ * vCPU.
+ *
+ * If the event has the disabled property, the check will have no performance
+ * impact.
+ */
+#define trace_event_get_vcpu_state(vcpu, id)                            \
+    ((id ##_ENABLED) &&                                                 \
+     trace_event_get_vcpu_state_dynamic_by_vcpu_id(                     \
+         vcpu, _ ## id ## _EVENT.vcpu_id))
+
+/**
+ * trace_event_get_vcpu_state_dynamic:
+ *
+ * Get the dynamic tracing state of an event for the given vCPU.
+ */
+static bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu, TraceEvent *ev);
+
+#include "control-internal.h"
+
+static inline bool
+trace_event_get_vcpu_state_dynamic_by_vcpu_id(CPUState *vcpu,
+                                              uint32_t vcpu_id)
+{
+    /* it's on fast path, avoid consistency checks (asserts) */
+    if (unlikely(trace_events_enabled_count)) {
+        return test_bit(vcpu_id, vcpu->trace_dstate);
+    } else {
+        return false;
+    }
+}
+
+static inline bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu,
+                                                      TraceEvent *ev)
+{
+    uint32_t vcpu_id;
+    assert(trace_event_is_vcpu(ev));
+    vcpu_id = trace_event_get_vcpu_id(ev);
+    return trace_event_get_vcpu_state_dynamic_by_vcpu_id(vcpu, vcpu_id);
+}
+
+#endif