Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

Tracing pull request

# gpg: Signature made Wed 07 May 2014 18:14:02 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/tracing-pull-request:
  configure: Show trace output file conditionally
  trace: [tracetool] Minimize the amount of per-backend code
  trace: [simple] Bump up log version number
  trace: [tracetool] Change format docs to point to the generated file
  trace: [tracetool] Show list of frontends and backends sorted by name
  trace: [tracetool] Cosmetic changes
  trace: [tracetool] Spacing changes
  trace: [tracetool] Add methods 'Event.copy' and 'Arguments.copy'
  trace: [tracetool] Add method 'Event.api' to build event names

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

21 files changed, 364 insertions, 434 deletions

diff --git a/configure b/configure
index ac2fa159c6..46bc0c91f4 100755
--- a/configure
+++ b/configure
@@ -4153,7 +4153,9 @@ echo "libcap-ng support $cap_ng"
 echo "vhost-net support $vhost_net"
 echo "vhost-scsi support $vhost_scsi"
 echo "Trace backend     $trace_backend"
+if test "$trace_backend" = "simple"; then
 echo "Trace output file $trace_file-<pid>"
+fi
 if test "$spice" = "yes"; then
 echo "spice support     $spice ($spice_protocol_version/$spice_server_version)"
 else
diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 8bbcb42cc4..800835a9d3 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -65,13 +65,13 @@ def read_trace_file(edict, fobj):
        header[0] != header_event_id or \
        header[1] != header_magic:
         raise ValueError('Not a valid trace file!')
-    if header[2] != 0 and \
-       header[2] != 2:
-        raise ValueError('Unknown version of tracelog format!')
 
     log_version = header[2]
-    if log_version == 0:
-        raise ValueError('Older log format, not supported with this QEMU release!')
+    if log_version not in [0, 2, 3]:
+        raise ValueError('Unknown version of tracelog format!')
+    if log_version != 3:
+        raise ValueError('Log format %d not supported with this QEMU release!'
+                         % log_version)
 
     while True:
         rec = read_record(edict, fobj)
@@ -109,14 +109,10 @@ def process(events, log, analyzer):
     if isinstance(log, str):
         log = open(log, 'rb')
 
-    enabled_events = []
     dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
     edict = {dropped_event_id: dropped_event}
 
-    for e in events:
-        if 'disable' not in e.properties:
-            enabled_events.append(e)
-    for num, event in enumerate(enabled_events):
+    for num, event in enumerate(events):
         edict[num] = event
 
     def build_fn(analyzer, event):
diff --git a/scripts/tracetool/__init__.py b/scripts/tracetool/__init__.py
index 175df08005..eccf5524f3 100644
--- a/scripts/tracetool/__init__.py
+++ b/scripts/tracetool/__init__.py
@@ -6,7 +6,7 @@ Machinery for generating tracing-related intermediate files.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -52,6 +52,10 @@ class Arguments:
         """
         self._args = args
 
+    def copy(self):
+        """Create a new copy."""
+        return Arguments(list(self._args))
+
     @staticmethod
     def build(arg_str):
         """Build and Arguments instance from an argument string.
@@ -144,7 +148,13 @@ class Event(object):
 
         unknown_props = set(self.properties) - self._VALID_PROPS
         if len(unknown_props) > 0:
-            raise ValueError("Unknown properties: %s" % ", ".join(unknown_props))
+            raise ValueError("Unknown properties: %s"
+                             % ", ".join(unknown_props))
+
+    def copy(self):
+        """Create a new copy."""
+        return Event(self.name, list(self.properties), self.fmt,
+                     self.args.copy(), self)
 
     @staticmethod
     def build(line_str):
@@ -173,6 +183,14 @@ class Event(object):
                                           self.args,
                                           self.fmt)
 
+    QEMU_TRACE               = "trace_%(name)s"
+
+    def api(self, fmt=None):
+        if fmt is None:
+            fmt = Event.QEMU_TRACE
+        return fmt % {"name": self.name}
+
+
 def _read_events(fobj):
     res = []
     for line in fobj:
@@ -189,7 +207,7 @@ class TracetoolError (Exception):
     pass
 
 
-def try_import(mod_name, attr_name = None, attr_default = None):
+def try_import(mod_name, attr_name=None, attr_default=None):
     """Try to import a module and get an attribute from it.
 
     Parameters
@@ -216,7 +234,7 @@ def try_import(mod_name, attr_name = None, attr_default = None):
 
 
 def generate(fevents, format, backend,
-             binary = None, probe_prefix = None):
+             binary=None, probe_prefix=None):
     """Generate the output for the given (format, backend) pair.
 
     Parameters
@@ -238,20 +256,17 @@ def generate(fevents, format, backend,
     format = str(format)
     if len(format) is 0:
         raise TracetoolError("format not set")
-    mformat = format.replace("-", "_")
-    if not tracetool.format.exists(mformat):
+    if not tracetool.format.exists(format):
         raise TracetoolError("unknown format: %s" % format)
+    format = format.replace("-", "_")
 
     backend = str(backend)
     if len(backend) is 0:
         raise TracetoolError("backend not set")
-    mbackend = backend.replace("-", "_")
-    if not tracetool.backend.exists(mbackend):
+    if not tracetool.backend.exists(backend):
         raise TracetoolError("unknown backend: %s" % backend)
-
-    if not tracetool.backend.compatible(mbackend, mformat):
-        raise TracetoolError("backend '%s' not compatible with format '%s'" %
-                             (backend, format))
+    backend = backend.replace("-", "_")
+    backend = tracetool.backend.Wrapper(backend, format)
 
     import tracetool.backend.dtrace
     tracetool.backend.dtrace.BINARY = binary
@@ -259,16 +274,4 @@ def generate(fevents, format, backend,
 
     events = _read_events(fevents)
 
-    if backend == "nop":
-        ( e.properies.add("disable") for e in events )
-
-    tracetool.format.generate_begin(mformat, events)
-    tracetool.backend.generate("nop", format,
-                               [ e
-                                 for e in events
-                                 if "disable" in e.properties ])
-    tracetool.backend.generate(backend, format,
-                               [ e
-                                 for e in events
-                                 if "disable" not in e.properties ])
-    tracetool.format.generate_end(mformat, events)
+    tracetool.format.generate(events, format, backend)
diff --git a/scripts/tracetool/backend/__init__.py b/scripts/tracetool/backend/__init__.py
index f0314ee376..5e36f0415d 100644
--- a/scripts/tracetool/backend/__init__.py
+++ b/scripts/tracetool/backend/__init__.py
@@ -30,17 +30,24 @@ PUBLIC    If exists and is set to 'True', the backend is considered "public".
 Backend functions
 -----------------
 
-======== =======================================================================
-Function Description
-======== =======================================================================
-<format> Called to generate the format- and backend-specific code for each of
-         the specified events. If the function does not exist, the backend is
-         considered not compatible with the given format.
-======== =======================================================================
+All the following functions are optional, and no output will be generated if
+they do not exist.
+
+=============================== ==============================================
+Function                        Description
+=============================== ==============================================
+generate_<format>_begin(events) Generate backend- and format-specific file
+                                header contents.
+generate_<format>_end(events)   Generate backend- and format-specific file
+                                footer contents.
+generate_<format>(event)        Generate backend- and format-specific contents
+                                for the given event.
+=============================== ==============================================
+
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -59,7 +66,7 @@ def get_list(only_public = False):
     for filename in os.listdir(tracetool.backend.__path__[0]):
         if filename.endswith('.py') and filename != '__init__.py':
             modnames.append(filename.rsplit('.', 1)[0])
-    for modname in modnames:
+    for modname in sorted(modnames):
         module = tracetool.try_import("tracetool.backend." + modname)
 
         # just in case; should never fail unless non-module files are put there
@@ -91,39 +98,24 @@ def exists(name):
     return tracetool.try_import("tracetool.backend." + name)[1]
 
 
-def compatible(backend, format):
-    """Whether a backend is compatible with the given format."""
-    if not exists(backend):
-        raise ValueError("unknown backend: %s" % backend)
-
-    backend = backend.replace("-", "_")
-    format = format.replace("-", "_")
-
-    if backend == "nop":
-        return True
-    else:
-        func = tracetool.try_import("tracetool.backend." + backend,
-                                    format, None)[1]
-        return func is not None
-
-
-def _empty(events):
-    pass
+class Wrapper:
+    def __init__(self, backend, format):
+        self._backend = backend.replace("-", "_")
+        self._format = format.replace("-", "_")
+        assert exists(self._backend)
+        assert tracetool.format.exists(self._format)
 
-def generate(backend, format, events):
-    """Generate the per-event output for the given (backend, format) pair."""
-    if not compatible(backend, format):
-        raise ValueError("backend '%s' not compatible with format '%s'" %
-                         (backend, format))
+    def _run_function(self, name, *args, **kwargs):
+        func = tracetool.try_import("tracetool.backend." + self._backend,
+                                    name % self._format, None)[1]
+        if func is not None:
+            func(*args, **kwargs)
 
-    backend = backend.replace("-", "_")
-    format = format.replace("-", "_")
+    def generate_begin(self, events):
+        self._run_function("generate_%s_begin", events)
 
-    if backend == "nop":
-        func = tracetool.try_import("tracetool.format." + format,
-                                    "nop", _empty)[1]
-    else:
-        func = tracetool.try_import("tracetool.backend." + backend,
-                                    format, None)[1]
+    def generate(self, event):
+        self._run_function("generate_%s", event)
 
-    func(events)
+    def generate_end(self, events):
+        self._run_function("generate_%s_end", events)
diff --git a/scripts/tracetool/backend/dtrace.py b/scripts/tracetool/backend/dtrace.py
index e31bc799f8..fabfe99881 100644
--- a/scripts/tracetool/backend/dtrace.py
+++ b/scripts/tracetool/backend/dtrace.py
@@ -6,7 +6,7 @@ DTrace/SystemTAP backend.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -21,7 +21,7 @@ PUBLIC = True
 
 PROBEPREFIX = None
 
-def _probeprefix():
+def probeprefix():
     if PROBEPREFIX is None:
         raise ValueError("you must set PROBEPREFIX")
     return PROBEPREFIX
@@ -29,81 +29,18 @@ def _probeprefix():
 
 BINARY = None
 
-def _binary():
+def binary():
     if BINARY is None:
         raise ValueError("you must set BINARY")
     return BINARY
 
 
-def c(events):
-    pass
-
-
-def h(events):
+def generate_h_begin(events):
     out('#include "trace/generated-tracers-dtrace.h"',
         '')
 
-    for e in events:
-        out('static inline void trace_%(name)s(%(args)s) {',
-            '    QEMU_%(uppername)s(%(argnames)s);',
-            '}',
-            name = e.name,
-            args = e.args,
-            uppername = e.name.upper(),
-            argnames = ", ".join(e.args.names()),
-            )
-
-
-def d(events):
-    out('provider qemu {')
-
-    for e in events:
-        args = str(e.args)
-
-        # DTrace provider syntax expects foo() for empty
-        # params, not foo(void)
-        if args == 'void':
-            args = ''
-
-        # Define prototype for probe arguments
-        out('',
-            'probe %(name)s(%(args)s);',
-            name = e.name,
-            args = args,
-            )
-
-    out('',
-        '};')
-
-
-# Technically 'self' is not used by systemtap yet, but
-# they recommended we keep it in the reserved list anyway
-RESERVED_WORDS = (
-    'break', 'catch', 'continue', 'delete', 'else', 'for',
-    'foreach', 'function', 'global', 'if', 'in', 'limit',
-    'long', 'next', 'probe', 'return', 'self', 'string',
-    'try', 'while'
-    )
-
-def stap(events):
-    for e in events:
-        # Define prototype for probe arguments
-        out('probe %(probeprefix)s.%(name)s = process("%(binary)s").mark("%(name)s")',
-            '{',
-            probeprefix = _probeprefix(),
-            name = e.name,
-            binary = _binary(),
-            )
-
-        i = 1
-        if len(e.args) > 0:
-            for name in e.args.names():
-                # Append underscore to reserved keywords
-                if name in RESERVED_WORDS:
-                    name += '_'
-                out('  %s = $arg%d;' % (name, i))
-                i += 1
-
-        out('}')
-
-    out()
+
+def generate_h(event):
+    out('    QEMU_%(uppername)s(%(argnames)s);',
+        uppername=event.name.upper(),
+        argnames=", ".join(event.args.names()))
diff --git a/scripts/tracetool/backend/events.py b/scripts/tracetool/backend/events.py
deleted file mode 100644
index 5afce3e8da..0000000000
--- a/scripts/tracetool/backend/events.py
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/usr/bin/env python
-# -*- coding: utf-8 -*-
-
-"""
-Generic event description.
-
-This is a dummy backend to establish appropriate frontend/backend compatibility
-checks.
-"""
-
-__author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
-__license__    = "GPL version 2 or (at your option) any later version"
-
-__maintainer__ = "Stefan Hajnoczi"
-__email__      = "stefanha@linux.vnet.ibm.com"
-
-
-def events_h(events):
-    pass
-
-def events_c(events):
-    pass
diff --git a/scripts/tracetool/backend/ftrace.py b/scripts/tracetool/backend/ftrace.py
index 888c361aec..d798c71347 100644
--- a/scripts/tracetool/backend/ftrace.py
+++ b/scripts/tracetool/backend/ftrace.py
@@ -19,36 +19,30 @@ from tracetool import out
 PUBLIC = True
 
 
-def c(events):
-    pass
-
-def h(events):
+def generate_h_begin(events):
     out('#include "trace/ftrace.h"',
         '#include "trace/control.h"',
-        '',
-        )
-
-    for e in events:
-        argnames = ", ".join(e.args.names())
-        if len(e.args) > 0:
-            argnames = ", " + argnames
-
-        out('static inline void trace_%(name)s(%(args)s)',
-            '{',
-            '    char ftrace_buf[MAX_TRACE_STRLEN];',
-            '    int unused __attribute__ ((unused));',
-            '    int trlen;',
-            '    bool _state = trace_event_get_state(%(event_id)s);',
-            '    if (_state) {',
-            '        trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
-            '                         "%(name)s " %(fmt)s "\\n" %(argnames)s);',
-            '        trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
-            '        unused = write(trace_marker_fd, ftrace_buf, trlen);',
-            '    }',
-            '}',
-            name = e.name,
-            args = e.args,
-            event_id = "TRACE_" + e.name.upper(),
-            fmt = e.fmt.rstrip("\n"),
-            argnames = argnames,
-            )
+        '')
+
+
+def generate_h(event):
+    argnames = ", ".join(event.args.names())
+    if len(event.args) > 0:
+        argnames = ", " + argnames
+
+    out('    {',
+        '        char ftrace_buf[MAX_TRACE_STRLEN];',
+        '        int unused __attribute__ ((unused));',
+        '        int trlen;',
+        '        if (trace_event_get_state(%(event_id)s)) {',
+        '            trlen = snprintf(ftrace_buf, MAX_TRACE_STRLEN,',
+        '                             "%(name)s " %(fmt)s "\\n" %(argnames)s);',
+        '            trlen = MIN(trlen, MAX_TRACE_STRLEN - 1);',
+        '            unused = write(trace_marker_fd, ftrace_buf, trlen);',
+        '        }',
+        '    }',
+        name=event.name,
+        args=event.args,
+        event_id="TRACE_" + event.name.upper(),
+        fmt=event.fmt.rstrip("\n"),
+        argnames=argnames)
diff --git a/scripts/tracetool/backend/simple.py b/scripts/tracetool/backend/simple.py
index 3dde372e46..e8c2cd57e9 100644
--- a/scripts/tracetool/backend/simple.py
+++ b/scripts/tracetool/backend/simple.py
@@ -6,7 +6,7 @@ Simple built-in backend.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -26,76 +26,74 @@ def is_string(arg):
     else:
         return False
 
-def c(events):
+
+def generate_h_begin(events):
+    for event in events:
+        out('void _simple_%(api)s(%(args)s);',
+            api=event.api(),
+            args=event.args)
+    out('')
+
+
+def generate_h(event):
+    out('    _simple_%(api)s(%(args)s);',
+        api=event.api(),
+        args=", ".join(event.args.names()))
+
+
+def generate_c_begin(events):
     out('#include "trace.h"',
         '#include "trace/control.h"',
         '#include "trace/simple.h"',
+        '')
+
+
+def generate_c(event):
+    out('void _simple_%(api)s(%(args)s)',
+        '{',
+        '    TraceBufferRecord rec;',
+        api=event.api(),
+        args=event.args)
+    sizes = []
+    for type_, name in event.args:
+        if is_string(type_):
+            out('    size_t arg%(name)s_len = %(name)s ? MIN(strlen(%(name)s), MAX_TRACE_STRLEN) : 0;',
+                name=name)
+            strsizeinfo = "4 + arg%s_len" % name
+            sizes.append(strsizeinfo)
+        else:
+            sizes.append("8")
+    sizestr = " + ".join(sizes)
+    if len(event.args) == 0:
+        sizestr = '0'
+
+
+    out('',
+        '    if (!trace_event_get_state(%(event_id)s)) {',
+        '        return;',
+        '    }',
         '',
-        )
-
-    for num, event in enumerate(events):
-        out('void trace_%(name)s(%(args)s)',
-            '{',
-            '    TraceBufferRecord rec;',
-            name = event.name,
-            args = event.args,
-            )
-        sizes = []
+        '    if (trace_record_start(&rec, %(event_id)s, %(size_str)s)) {',
+        '        return; /* Trace Buffer Full, Event Dropped ! */',
+        '    }',
+        event_id='TRACE_' + event.name.upper(),
+        size_str=sizestr)
+
+    if len(event.args) > 0:
         for type_, name in event.args:
+            # string
             if is_string(type_):
-                out('    size_t arg%(name)s_len = %(name)s ? MIN(strlen(%(name)s), MAX_TRACE_STRLEN) : 0;',
-                    name = name,
-                   )
-                strsizeinfo = "4 + arg%s_len" % name
-                sizes.append(strsizeinfo)
+                out('    trace_record_write_str(&rec, %(name)s, arg%(name)s_len);',
+                    name=name)
+            # pointer var (not string)
+            elif type_.endswith('*'):
+                out('    trace_record_write_u64(&rec, (uintptr_t)(uint64_t *)%(name)s);',
+                    name=name)
+            # primitive data type
             else:
-                sizes.append("8")
-        sizestr = " + ".join(sizes)
-        if len(event.args) == 0:
-            sizestr = '0'
-
-
-        out('',
-            '    TraceEvent *eventp = trace_event_id(%(event_enum)s);',
-            '    bool _state = trace_event_get_state_dynamic(eventp);',
-            '    if (!_state) {',
-            '        return;',
-            '    }',
-            '',
-            '    if (trace_record_start(&rec, %(event_id)s, %(size_str)s)) {',
-            '        return; /* Trace Buffer Full, Event Dropped ! */',
-            '    }',
-            event_enum = 'TRACE_' + event.name.upper(),
-            event_id = num,
-            size_str = sizestr,
-            )
-
-        if len(event.args) > 0:
-            for type_, name in event.args:
-                # string
-                if is_string(type_):
-                    out('    trace_record_write_str(&rec, %(name)s, arg%(name)s_len);',
-                        name = name,
-                       )
-                # pointer var (not string)
-                elif type_.endswith('*'):
-                    out('    trace_record_write_u64(&rec, (uintptr_t)(uint64_t *)%(name)s);',
-                        name = name,
-                       )
-                # primitive data type
-                else:
-                    out('    trace_record_write_u64(&rec, (uint64_t)%(name)s);',
-                       name = name,
-                       )
-
-        out('    trace_record_finish(&rec);',
-            '}',
-            '')
-
-
-def h(events):
-    for event in events:
-        out('void trace_%(name)s(%(args)s);',
-            name = event.name,
-            args = event.args,
-            )
+                out('    trace_record_write_u64(&rec, (uint64_t)%(name)s);',
+                   name=name)
+
+    out('    trace_record_finish(&rec);',
+        '}',
+        '')
diff --git a/scripts/tracetool/backend/stderr.py b/scripts/tracetool/backend/stderr.py
index 6f93dbd1ae..2a1e9064c3 100644
--- a/scripts/tracetool/backend/stderr.py
+++ b/scripts/tracetool/backend/stderr.py
@@ -6,7 +6,7 @@ Stderr built-in backend.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -19,30 +19,21 @@ from tracetool import out
 PUBLIC = True
 
 
-def c(events):
-    pass
-
-def h(events):
+def generate_h_begin(events):
     out('#include <stdio.h>',
         '#include "trace/control.h"',
-        '',
-        )
-
-    for e in events:
-        argnames = ", ".join(e.args.names())
-        if len(e.args) > 0:
-            argnames = ", " + argnames
-
-        out('static inline void trace_%(name)s(%(args)s)',
-            '{',
-            '    bool _state = trace_event_get_state(%(event_id)s);',
-            '    if (_state) {',
-            '        fprintf(stderr, "%(name)s " %(fmt)s "\\n" %(argnames)s);',
-            '    }',
-            '}',
-            name = e.name,
-            args = e.args,
-            event_id = "TRACE_" + e.name.upper(),
-            fmt = e.fmt.rstrip("\n"),
-            argnames = argnames,
-            )
+        '')
+
+
+def generate_h(event):
+    argnames = ", ".join(event.args.names())
+    if len(event.args) > 0:
+        argnames = ", " + argnames
+
+    out('    if (trace_event_get_state(%(event_id)s)) {',
+        '        fprintf(stderr, "%(name)s " %(fmt)s "\\n" %(argnames)s);',
+        '    }',
+        event_id="TRACE_" + event.name.upper(),
+        name=event.name,
+        fmt=event.fmt.rstrip("\n"),
+        argnames=argnames)
diff --git a/scripts/tracetool/backend/ust.py b/scripts/tracetool/backend/ust.py
index 41c1c75b7c..2f8f44abde 100644
--- a/scripts/tracetool/backend/ust.py
+++ b/scripts/tracetool/backend/ust.py
@@ -6,7 +6,7 @@ LTTng User Space Tracing backend.
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -18,65 +18,18 @@ from tracetool import out
 
 PUBLIC = True
 
-def c(events):
-    pass
 
-
-def h(events):
+def generate_h_begin(events):
     out('#include <lttng/tracepoint.h>',
         '#include "trace/generated-ust-provider.h"',
         '')
-    for e in events:
-        argnames = ", ".join(e.args.names())
-        if len(e.args) > 0:
-            argnames = ", " + argnames
-
-        out('static inline void trace_%(name)s(%(args)s)',
-            '{',
-            '    tracepoint(qemu, %(name)s%(tp_args)s);',
-            '}',
-            '',
-            name = e.name,
-            args = e.args,
-            tp_args = argnames,
-            )
-
-def ust_events_c(events):
-    pass
-
-def ust_events_h(events):
-    for e in events:
-        if len(e.args) > 0:
-            out('TRACEPOINT_EVENT(',
-                '   qemu,',
-                '   %(name)s,',
-                '   TP_ARGS(%(args)s),',
-                '   TP_FIELDS(',
-                name = e.name,
-                args = ", ".join(", ".join(i) for i in e.args),
-                )
 
-            for t,n in e.args:
-                if ('int' in t) or ('long' in t) or ('unsigned' in t) or ('size_t' in t):
-                    out('       ctf_integer(' + t + ', ' + n + ', ' + n + ')')
-                elif ('double' in t) or ('float' in t):
-                    out('       ctf_float(' + t + ', ' + n + ', ' + n + ')')
-                elif ('char *' in t) or ('char*' in t):
-                    out('       ctf_string(' + n + ', ' + n + ')')
-                elif ('void *' in t) or ('void*' in t):
-                    out('       ctf_integer_hex(unsigned long, ' + n + ', ' + n + ')')
 
-            out('   )',
-                ')',
-                '')
+def generate_h(event):
+    argnames = ", ".join(event.args.names())
+    if len(event.args) > 0:
+        argnames = ", " + argnames
 
-        else:
-            out('TRACEPOINT_EVENT(',
-                '   qemu,',
-                '   %(name)s,',
-                '   TP_ARGS(void),',
-                '   TP_FIELDS()',
-                ')',
-                '',
-                name = e.name,
-                )
\ No newline at end of file
+    out('    tracepoint(qemu, %(name)s%(tp_args)s);',
+        name=event.name,
+        tp_args=argnames)
diff --git a/scripts/tracetool/format/__init__.py b/scripts/tracetool/format/__init__.py
index 3c2a0d89e0..812570ff6f 100644
--- a/scripts/tracetool/format/__init__.py
+++ b/scripts/tracetool/format/__init__.py
@@ -20,21 +20,16 @@ All formats must generate their contents through the 'tracetool.out' routine.
 Format functions
 ----------------
 
-All the following functions are optional, and no output will be generated if
-they do not exist.
-
-======== =======================================================================
+======== ==================================================================
 Function Description
-======== =======================================================================
-begin    Called to generate the format-specific file header.
-end      Called to generate the format-specific file footer.
-nop      Called to generate the per-event contents when the event is disabled or
-         the selected backend is 'nop'.
-======== =======================================================================
+======== ==================================================================
+generate Called to generate a format-specific file.
+======== ==================================================================
+
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -53,7 +48,7 @@ def get_list():
     for filename in os.listdir(tracetool.format.__path__[0]):
         if filename.endswith('.py') and filename != '__init__.py':
             modnames.append(filename.rsplit('.', 1)[0])
-    for modname in modnames:
+    for modname in sorted(modnames):
         module = tracetool.try_import("tracetool.format." + modname)
 
         # just in case; should never fail unless non-module files are put there
@@ -79,25 +74,12 @@ def exists(name):
     return tracetool.try_import("tracetool.format." + name)[1]
 
 
-def _empty(events):
-    pass
-
-def generate_begin(name, events):
-    """Generate the header of the format-specific file."""
-    if not exists(name):
-        raise ValueError("unknown format: %s" % name)
-
-    name = name.replace("-", "_")
-    func = tracetool.try_import("tracetool.format." + name,
-                                "begin", _empty)[1]
-    func(events)
-
-def generate_end(name, events):
-    """Generate the footer of the format-specific file."""
-    if not exists(name):
-        raise ValueError("unknown format: %s" % name)
-
-    name = name.replace("-", "_")
-    func = tracetool.try_import("tracetool.format." + name,
-                                "end", _empty)[1]
-    func(events)
+def generate(events, format, backend):
+    if not exists(format):
+        raise ValueError("unknown format: %s" % format)
+    format = format.replace("-", "_")
+    func = tracetool.try_import("tracetool.format." + format,
+                                "generate")[1]
+    if func is None:
+        raise AttributeError("format has no 'generate': %s" % format)
+    func(events, backend)
diff --git a/scripts/tracetool/format/c.py b/scripts/tracetool/format/c.py
index 35555aee1f..699598fb02 100644
--- a/scripts/tracetool/format/c.py
+++ b/scripts/tracetool/format/c.py
@@ -2,11 +2,11 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .c file.
+trace/generated-tracers.c
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -16,5 +16,13 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 from tracetool import out
 
 
-def begin(events):
-    out('/* This file is autogenerated by tracetool, do not edit. */')
+def generate(events, backend):
+    events = [e for e in events
+              if "disable" not in e.properties]
+
+    out('/* This file is autogenerated by tracetool, do not edit. */',
+        '')
+    backend.generate_begin(events)
+    for event in events:
+        backend.generate(event)
+    backend.generate_end(events)
diff --git a/scripts/tracetool/format/d.py b/scripts/tracetool/format/d.py
index a2d594773c..46eebb128b 100644
--- a/scripts/tracetool/format/d.py
+++ b/scripts/tracetool/format/d.py
@@ -2,11 +2,11 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .d file (DTrace only).
+trace/generated-tracers.dtrace (DTrace only).
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -16,5 +16,27 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 from tracetool import out
 
 
-def begin(events):
-    out('/* This file is autogenerated by tracetool, do not edit. */')
+def generate(events, backend):
+    events = [e for e in events
+              if "disable" not in e.properties]
+
+    out('/* This file is autogenerated by tracetool, do not edit. */'
+        '',
+        'provider qemu {')
+
+    for e in events:
+        args = str(e.args)
+
+        # DTrace provider syntax expects foo() for empty
+        # params, not foo(void)
+        if args == 'void':
+            args = ''
+
+        # Define prototype for probe arguments
+        out('',
+            'probe %(name)s(%(args)s);',
+            name=e.name,
+            args=args)
+
+    out('',
+        '};')
diff --git a/scripts/tracetool/format/events_c.py b/scripts/tracetool/format/events_c.py
index d670ec83d5..2d97fa310a 100644
--- a/scripts/tracetool/format/events_c.py
+++ b/scripts/tracetool/format/events_c.py
@@ -2,11 +2,11 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .c for event description.
+trace/generated-events.c
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -16,14 +16,13 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 from tracetool import out
 
 
-def begin(events):
+def generate(events, backend):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#include "trace.h"',
         '#include "trace/generated-events.h"',
         '#include "trace/control.h"',
-        '',
-        )
+        '')
 
     out('TraceEvent trace_events[TRACE_EVENT_COUNT] = {')
 
@@ -31,9 +30,7 @@ def begin(events):
         out('    { .id = %(id)s, .name = \"%(name)s\", .sstate = %(sstate)s, .dstate = 0 },',
             id = "TRACE_" + e.name.upper(),
             name = e.name,
-            sstate = "TRACE_%s_ENABLED" % e.name.upper(),
-            )
+            sstate = "TRACE_%s_ENABLED" % e.name.upper())
 
     out('};',
-        '',
-        )
+        '')
diff --git a/scripts/tracetool/format/events_h.py b/scripts/tracetool/format/events_h.py
index d30ccea8a1..25d913bb25 100644
--- a/scripts/tracetool/format/events_h.py
+++ b/scripts/tracetool/format/events_h.py
@@ -2,11 +2,11 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .h for event description.
+trace/generated-events.h
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -16,15 +16,14 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 from tracetool import out
 
 
-def begin(events):
+def generate(events, backend):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#ifndef TRACE__GENERATED_EVENTS_H',
         '#define TRACE__GENERATED_EVENTS_H',
         '',
         '#include <stdbool.h>',
-        ''
-        )
+        '')
 
     # event identifiers
     out('typedef enum {')
@@ -33,8 +32,7 @@ def begin(events):
         out('    TRACE_%s,' % e.name.upper())
 
     out('    TRACE_EVENT_COUNT',
-        '} TraceEventID;',
-        )
+        '} TraceEventID;')
 
     # static state
     for e in events:
@@ -46,5 +44,4 @@ def begin(events):
 
     out('#include "trace/event-internal.h"',
         '',
-        '#endif  /* TRACE__GENERATED_EVENTS_H */',
-        )
+        '#endif  /* TRACE__GENERATED_EVENTS_H */')
diff --git a/scripts/tracetool/format/h.py b/scripts/tracetool/format/h.py
index 93132fceaf..9b3943002c 100644
--- a/scripts/tracetool/format/h.py
+++ b/scripts/tracetool/format/h.py
@@ -2,11 +2,11 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .h file.
+trace/generated-tracers.h
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -16,23 +16,29 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 from tracetool import out
 
 
-def begin(events):
+def generate(events, backend):
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#ifndef TRACE__GENERATED_TRACERS_H',
         '#define TRACE__GENERATED_TRACERS_H',
         '',
-        '#include "qemu-common.h"')
+        '#include "qemu-common.h"',
+        '')
 
-def end(events):
-    out('#endif /* TRACE__GENERATED_TRACERS_H */')
+    backend.generate_begin(events)
 
-def nop(events):
     for e in events:
         out('',
-            'static inline void trace_%(name)s(%(args)s)',
+            'static inline void %(api)s(%(args)s)',
             '{',
-            '}',
-            name = e.name,
-            args = e.args,
-            )
+            api=e.api(),
+            args=e.args)
+
+        if "disable" not in e.properties:
+            backend.generate(e)
+
+        out('}')
+
+    backend.generate_end(events)
+
+    out('#endif /* TRACE__GENERATED_TRACERS_H */')
diff --git a/scripts/tracetool/format/stap.py b/scripts/tracetool/format/stap.py
index 50a4c69954..e24abf7f11 100644
--- a/scripts/tracetool/format/stap.py
+++ b/scripts/tracetool/format/stap.py
@@ -6,7 +6,7 @@ Generate .stp file (DTrace with SystemTAP only).
 """
 
 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
-__copyright__  = "Copyright 2012, Lluís Vilanova <vilanova@ac.upc.edu>"
+__copyright__  = "Copyright 2012-2014, Lluís Vilanova <vilanova@ac.upc.edu>"
 __license__    = "GPL version 2 or (at your option) any later version"
 
 __maintainer__ = "Stefan Hajnoczi"
@@ -14,7 +14,43 @@ __email__      = "stefanha@linux.vnet.ibm.com"
 
 
 from tracetool import out
+from tracetool.backend.dtrace import binary, probeprefix
 
 
-def begin(events):
-    out('/* This file is autogenerated by tracetool, do not edit. */')
+# Technically 'self' is not used by systemtap yet, but
+# they recommended we keep it in the reserved list anyway
+RESERVED_WORDS = (
+    'break', 'catch', 'continue', 'delete', 'else', 'for',
+    'foreach', 'function', 'global', 'if', 'in', 'limit',
+    'long', 'next', 'probe', 'return', 'self', 'string',
+    'try', 'while'
+    )
+
+
+def generate(events, backend):
+    events = [e for e in events
+              if "disable" not in e.properties]
+
+    out('/* This file is autogenerated by tracetool, do not edit. */',
+        '')
+
+    for e in events:
+        # Define prototype for probe arguments
+        out('probe %(probeprefix)s.%(name)s = process("%(binary)s").mark("%(name)s")',
+            '{',
+            probeprefix=probeprefix(),
+            name=e.name,
+            binary=binary())
+
+        i = 1
+        if len(e.args) > 0:
+            for name in e.args.names():
+                # Append underscore to reserved keywords
+                if name in RESERVED_WORDS:
+                    name += '_'
+                out('  %s = $arg%d;' % (name, i))
+                i += 1
+
+        out('}')
+
+    out()
diff --git a/scripts/tracetool/format/ust_events_c.py b/scripts/tracetool/format/ust_events_c.py
index 116e713225..bc970936be 100644
--- a/scripts/tracetool/format/ust_events_c.py
+++ b/scripts/tracetool/format/ust_events_c.py
@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .c for LTTng ust event description.
+trace/generated-ust.c
 """
 
 __author__     = "Mohamad Gebai <mohamad.gebai@polymtl.ca>"
@@ -16,7 +16,10 @@ __email__      = "stefanha@redhat.com"
 from tracetool import out
 
 
-def begin(events):
+def generate(events, backend):
+    events = [e for e in events
+              if "disabled" not in e.properties]
+
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#define TRACEPOINT_DEFINE',
diff --git a/scripts/tracetool/format/ust_events_h.py b/scripts/tracetool/format/ust_events_h.py
index f206eca6ec..5102565470 100644
--- a/scripts/tracetool/format/ust_events_h.py
+++ b/scripts/tracetool/format/ust_events_h.py
@@ -2,7 +2,7 @@
 # -*- coding: utf-8 -*-
 
 """
-Generate .h for LTTng ust event description.
+trace/generated-ust-provider.h
 """
 
 __author__     = "Mohamad Gebai <mohamad.gebai@polymtl.ca>"
@@ -16,7 +16,10 @@ __email__      = "stefanha@redhat.com"
 from tracetool import out
 
 
-def begin(events):
+def generate(events, backend):
+    events = [e for e in events
+              if "disabled" not in e.properties]
+
     out('/* This file is autogenerated by tracetool, do not edit. */',
         '',
         '#undef TRACEPOINT_PROVIDER',
@@ -50,7 +53,40 @@ def begin(events):
         '#endif',
         '')
 
-def end(events):
+    for e in events:
+        if len(e.args) > 0:
+            out('TRACEPOINT_EVENT(',
+                '   qemu,',
+                '   %(name)s,',
+                '   TP_ARGS(%(args)s),',
+                '   TP_FIELDS(',
+                name=e.name,
+                args=", ".join(", ".join(i) for i in e.args))
+
+            for t, n in e.args:
+                if ('int' in t) or ('long' in t) or ('unsigned' in t) or ('size_t' in t):
+                    out('       ctf_integer(' + t + ', ' + n + ', ' + n + ')')
+                elif ('double' in t) or ('float' in t):
+                    out('       ctf_float(' + t + ', ' + n + ', ' + n + ')')
+                elif ('char *' in t) or ('char*' in t):
+                    out('       ctf_string(' + n + ', ' + n + ')')
+                elif ('void *' in t) or ('void*' in t):
+                    out('       ctf_integer_hex(unsigned long, ' + n + ', ' + n + ')')
+
+            out('   )',
+                ')',
+                '')
+
+        else:
+            out('TRACEPOINT_EVENT(',
+                '   qemu,',
+                '   %(name)s,',
+                '   TP_ARGS(void),',
+                '   TP_FIELDS()',
+                ')',
+                '',
+                name=e.name)
+
     out('#endif /* TRACE__GENERATED_UST_H */',
         '',
         '/* This part must be outside ifdef protection */',
diff --git a/trace/Makefile.objs b/trace/Makefile.objs
index d321946d38..6a30467096 100644
--- a/trace/Makefile.objs
+++ b/trace/Makefile.objs
@@ -31,7 +31,7 @@ $(obj)/generated-events.h: $(obj)/generated-events.h-timestamp
 $(obj)/generated-events.h-timestamp: $(SRC_PATH)/trace-events
 	$(call quiet-command,$(TRACETOOL) \
 		--format=events-h \
-		--backend=events \
+		--backend=$(TRACE_BACKEND) \
 		< $< > $@,"  GEN   $(patsubst %-timestamp,%,$@)")
 	@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
 
@@ -39,7 +39,7 @@ $(obj)/generated-events.c: $(obj)/generated-events.c-timestamp $(BUILD_DIR)/conf
 $(obj)/generated-events.c-timestamp: $(SRC_PATH)/trace-events
 	$(call quiet-command,$(TRACETOOL) \
 		--format=events-c \
-		--backend=events \
+		--backend=$(TRACE_BACKEND) \
 		< $< > $@,"  GEN   $(patsubst %-timestamp,%,$@)")
 	@cmp -s $@ $(patsubst %-timestamp,%,$@) || cp $@ $(patsubst %-timestamp,%,$@)
 
diff --git a/trace/simple.c b/trace/simple.c
index aaa010ee2b..bb0b52ce02 100644
--- a/trace/simple.c
+++ b/trace/simple.c
@@ -28,7 +28,7 @@
 #define HEADER_MAGIC 0xf2b177cb0aa429b4ULL
 
 /** Trace file version number, bump if format changes */
-#define HEADER_VERSION 2
+#define HEADER_VERSION 3
 
 /** Records were dropped event ID */
 #define DROPPED_EVENT_ID (~(uint64_t)0 - 1)