[Qemu-devel] [PATCH 04/13] instrument: Allow adding the "instrument" property without modifying event files

[Lluís Vilanova]

Adds a configure argument to allow users to add the instrument property
to events without having to modify any trace event files.

Signed-off-by: Lluís Vilanova <address@hidden>
---
 configure                     |   17 +++++++++++++++++
 rules.mak                     |    3 +++
 scripts/tracetool.py          |   11 +++++++++--
 scripts/tracetool/__init__.py |   20 +++++++++++++++++++-
 4 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/configure b/configure
index 13191052cb..8ab2a36130 100755
--- a/configure
+++ b/configure
@@ -353,6 +353,7 @@ trace_backends="log"
 trace_file="trace"
 trace_instrument="no"
 trace_instrument_backend="none"
+instrument_events=""
 spice=""
 rbd=""
 smartcard=""
@@ -901,6 +902,13 @@ for opt do
       trace_instrument="yes"
       trace_instrument_backend="dynamic"
   ;;
+  --with-instrument-events=*)
+      if test ! -f "$optarg"; then
+          echo "ERROR: no such file: $optarg"
+          exit 1
+      fi
+      instrument_events="`realpath $optarg`"
+  ;;
   --enable-gprof) gprof="yes"
   ;;
   --enable-gcov) gcov="yes"
@@ -1433,6 +1441,9 @@ Advanced options (experts only):
                            Default:trace-<pid>
   --enable-trace-instrument
                            Enable trace instrumentation
+  --with-instrument-events=FILE
+                           File with a list of events to enable instrumentation
+                           on (one per line)
   --disable-slirp          disable SLIRP userspace network connectivity
   --enable-tcg-interpreter enable TCG with bytecode interpreter (TCI)
   --oss-lib                path to OSS library
@@ -5291,6 +5302,9 @@ if have_backend "simple"; then
 echo "Trace output file $trace_file-<pid>"
 fi
 echo "Trace instrumentation $trace_instrument"
+if test -n "$instrument_events"; then
+echo "Instrument events $instrument_events"
+fi
 echo "spice support     $spice $(echo_version $spice 
$spice_protocol_version/$spice_server_version)"
 echo "rbd support       $rbd"
 echo "xfsctl support    $xfs"
@@ -6004,6 +6018,9 @@ echo 
"TRACE_INSTRUMENT_BACKEND=instr-$trace_instrument_backend" >> $config_host_
 if test "$trace_instrument" = "yes"; then
     echo "CONFIG_INSTRUMENT=y" >> $config_host_mak
 fi
+if test -n "$instrument_events"; then
+    echo "CONFIG_INSTRUMENT_EVENTS=$instrument_events" >> $config_host_mak
+fi
 ##########################################
 
 echo "TOOLS=$tools" >> $config_host_mak
diff --git a/rules.mak b/rules.mak
index 6e943335f3..fbeda68022 100644
--- a/rules.mak
+++ b/rules.mak
@@ -188,6 +188,9 @@ notempty = $(if $1,y,n)
 
 # Generate files with tracetool
 TRACETOOL=$(PYTHON) $(SRC_PATH)/scripts/tracetool.py
+ifdef CONFIG_INSTRUMENT_EVENTS
+TRACETOOL += --instrument=$(CONFIG_INSTRUMENT_EVENTS)
+endif
 
 # Generate timestamp files for .h include files
 
diff --git a/scripts/tracetool.py b/scripts/tracetool.py
index c55a21518b..d5d212e98f 100755
--- a/scripts/tracetool.py
+++ b/scripts/tracetool.py
@@ -6,7 +6,7 @@ Command-line wrapper for the tracetool machinery.
 """
 
 __author__     = "Lluís Vilanova <address@hidden>"
-__copyright__  = "Copyright 2012-2014, Lluís Vilanova <address@hidden>"
+__copyright__  = "Copyright 2012-2017, Lluís Vilanova <address@hidden>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -70,6 +70,7 @@ def main(args):
     long_opts = ["backends=", "format=", "help", "list-backends",
                  "check-backends", "group="]
     long_opts += ["binary=", "target-type=", "target-name=", "probe-prefix="]
+    long_opts += ["instrument="]
 
     try:
         opts, args = getopt.getopt(args[1:], "", long_opts)
@@ -84,6 +85,7 @@ def main(args):
     target_type = None
     target_name = None
     probe_prefix = None
+    instrument = None
     for opt, arg in opts:
         if opt == "--help":
             error_opt()
@@ -111,6 +113,9 @@ def main(args):
         elif opt == '--probe-prefix':
             probe_prefix = arg
 
+        elif opt == "--instrument":
+            instrument = arg
+
         else:
             error_opt("unhandled option: %s" % opt)
 
@@ -137,12 +142,14 @@ def main(args):
         if probe_prefix is None:
             probe_prefix = ".".join(["qemu", target_type, target_name])
 
+    instrument_cre = tracetool.read_instrument(instrument)
+
     if len(args) < 1:
         error_opt("missing trace-events filepath")
     events = []
     for arg in args:
         with open(arg, "r") as fh:
-            events.extend(tracetool.read_events(fh))
+            events.extend(tracetool.read_events(fh, instrument_cre))
 
     try:
         tracetool.generate(events, arg_group, arg_format, arg_backends,
diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index e65349bc33..b9ddf8fbf9 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -292,13 +292,26 @@ class Event(object):
                      self)
 
 
-def read_events(fobj):
+def read_instrument(path):
+    if path is None:
+        return None
+
+    with open(path) as f:
+        patterns = f.readlines()
+        patterns = [p.replace("\n", "") for p in patterns]
+        patterns = [p.replace("*", ".*") for p in patterns]
+        pattern = "|".join(patterns)
+        return re.compile(pattern)
+
+def read_events(fobj, instrument):
     """Generate the output for the given (format, backends) pair.
 
     Parameters
     ----------
     fobj : file
         Event description file.
+    instrument : cre or None
+        Event patterns to instrument.
 
     Returns a list of Event objects
     """
@@ -312,6 +325,11 @@ def read_events(fobj):
 
         event = Event.build(line)
 
+        if instrument is not None and instrument.match(event.name):
+            event.properties = [p for p in event.properties
+                                if p != "disable"]
+            event.properties.append("instrument")
+
         # transform TCG-enabled events
         if "tcg" not in event.properties:
             events.append(event)