trace: Add per-vCPU tracing states for events with the 'vcpu' property

Each vCPU gets a 'trace_dstate' bitmap to control the per-vCPU dynamic
tracing state of events with the 'vcpu' property.

Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/trace/control-target.c b/trace/control-target.c
new file mode 100644
index 0000000000..74c029accc
--- /dev/null
+++ b/trace/control-target.c
@@ -0,0 +1,53 @@
+/*
+ * 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 "cpu.h"
+#include "trace/control.h"
+#include "translate-all.h"
+
+
+void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
+{
+    CPUState *vcpu;
+    assert(trace_event_get_state_static(ev));
+    if (trace_event_is_vcpu(ev)) {
+        CPU_FOREACH(vcpu) {
+            trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
+        }
+    } else {
+        TraceEventID id = trace_event_get_id(ev);
+        trace_events_enabled_count += state - trace_events_dstate[id];
+        trace_events_dstate[id] = state;
+    }
+}
+
+void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
+                                        TraceEvent *ev, bool state)
+{
+    TraceEventID id;
+    TraceEventVCPUID vcpu_id;
+    bool state_pre;
+    assert(trace_event_get_state_static(ev));
+    assert(trace_event_is_vcpu(ev));
+    id = trace_event_get_id(ev);
+    vcpu_id = trace_event_get_vcpu_id(ev);
+    state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
+    if (state_pre != state) {
+        if (state) {
+            trace_events_enabled_count++;
+            set_bit(vcpu_id, vcpu->trace_dstate);
+            trace_events_dstate[id]++;
+        } else {
+            trace_events_enabled_count--;
+            clear_bit(vcpu_id, vcpu->trace_dstate);
+            trace_events_dstate[id]--;
+        }
+    }
+}