mirror of
https://github.com/qemu/qemu.git
synced 2024-11-24 03:13:44 +08:00
3470fef15a
By moving the dynamic argument construction to keyword-arguments, we can remove all of the specialized handling, and streamline it. If a tracing method wants to access these, they can define the kwargs, or ignore it be placing `**kwargs` at the end of the function's arguments list. Added deprecation warning to Analyzer class to make users aware of the Analyzer2 class. No removal date is planned. Signed-off-by: Mads Ynddal <m.ynddal@samsung.com> Message-id: 20230926103436.25700-13-mads@ynddal.dk Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
360 lines
13 KiB
Python
Executable File
360 lines
13 KiB
Python
Executable File
#!/usr/bin/env python3
|
|
#
|
|
# Pretty-printer for simple trace backend binary trace files
|
|
#
|
|
# Copyright IBM, Corp. 2010
|
|
#
|
|
# This work is licensed under the terms of the GNU GPL, version 2. See
|
|
# the COPYING file in the top-level directory.
|
|
#
|
|
# For help see docs/devel/tracing.rst
|
|
|
|
import sys
|
|
import struct
|
|
import inspect
|
|
import warnings
|
|
from tracetool import read_events, Event
|
|
from tracetool.backend.simple import is_string
|
|
|
|
__all__ = ['Analyzer', 'Analyzer2', 'process', 'run']
|
|
|
|
# This is the binary format that the QEMU "simple" trace backend
|
|
# emits. There is no specification documentation because the format is
|
|
# not guaranteed to be stable. Trace files must be parsed with the
|
|
# same trace-events-all file and the same simpletrace.py file that
|
|
# QEMU was built with.
|
|
header_event_id = 0xffffffffffffffff
|
|
header_magic = 0xf2b177cb0aa429b4
|
|
dropped_event_id = 0xfffffffffffffffe
|
|
|
|
record_type_mapping = 0
|
|
record_type_event = 1
|
|
|
|
log_header_fmt = '=QQQ'
|
|
rec_header_fmt = '=QQII'
|
|
rec_header_fmt_len = struct.calcsize(rec_header_fmt)
|
|
|
|
class SimpleException(Exception):
|
|
pass
|
|
|
|
def read_header(fobj, hfmt):
|
|
'''Read a trace record header'''
|
|
hlen = struct.calcsize(hfmt)
|
|
hdr = fobj.read(hlen)
|
|
if len(hdr) != hlen:
|
|
raise SimpleException('Error reading header. Wrong filetype provided?')
|
|
return struct.unpack(hfmt, hdr)
|
|
|
|
def get_mapping(fobj):
|
|
(event_id, ) = struct.unpack('=Q', fobj.read(8))
|
|
(len, ) = struct.unpack('=L', fobj.read(4))
|
|
name = fobj.read(len).decode()
|
|
|
|
return (event_id, name)
|
|
|
|
def read_record(fobj):
|
|
"""Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, args)."""
|
|
event_id, timestamp_ns, record_length, record_pid = read_header(fobj, rec_header_fmt)
|
|
args_payload = fobj.read(record_length - rec_header_fmt_len)
|
|
return (event_id, timestamp_ns, record_pid, args_payload)
|
|
|
|
def read_trace_header(fobj):
|
|
"""Read and verify trace file header"""
|
|
_header_event_id, _header_magic, log_version = read_header(fobj, log_header_fmt)
|
|
if _header_event_id != header_event_id:
|
|
raise ValueError(f'Not a valid trace file, header id {_header_event_id} != {header_event_id}')
|
|
if _header_magic != header_magic:
|
|
raise ValueError(f'Not a valid trace file, header magic {_header_magic} != {header_magic}')
|
|
|
|
if log_version not in [0, 2, 3, 4]:
|
|
raise ValueError(f'Unknown version {log_version} of tracelog format!')
|
|
if log_version != 4:
|
|
raise ValueError(f'Log format {log_version} not supported with this QEMU release!')
|
|
|
|
def read_trace_records(events, fobj, read_header):
|
|
"""Deserialize trace records from a file, yielding record tuples (event, event_num, timestamp, pid, arg1, ..., arg6).
|
|
|
|
Args:
|
|
event_mapping (str -> Event): events dict, indexed by name
|
|
fobj (file): input file
|
|
read_header (bool): whether headers were read from fobj
|
|
|
|
"""
|
|
frameinfo = inspect.getframeinfo(inspect.currentframe())
|
|
dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)",
|
|
frameinfo.lineno + 1, frameinfo.filename)
|
|
|
|
event_mapping = {e.name: e for e in events}
|
|
event_mapping["dropped"] = dropped_event
|
|
event_id_to_name = {dropped_event_id: "dropped"}
|
|
|
|
# If there is no header assume event ID mapping matches events list
|
|
if not read_header:
|
|
for event_id, event in enumerate(events):
|
|
event_id_to_name[event_id] = event.name
|
|
|
|
while True:
|
|
t = fobj.read(8)
|
|
if len(t) == 0:
|
|
break
|
|
|
|
(rectype, ) = struct.unpack('=Q', t)
|
|
if rectype == record_type_mapping:
|
|
event_id, event_name = get_mapping(fobj)
|
|
event_id_to_name[event_id] = event_name
|
|
else:
|
|
event_id, timestamp_ns, pid, args_payload = read_record(fobj)
|
|
event_name = event_id_to_name[event_id]
|
|
|
|
try:
|
|
event = event_mapping[event_name]
|
|
except KeyError as e:
|
|
raise SimpleException(
|
|
f'{e} event is logged but is not declared in the trace events'
|
|
'file, try using trace-events-all instead.'
|
|
)
|
|
|
|
offset = 0
|
|
args = []
|
|
for type, _ in event.args:
|
|
if is_string(type):
|
|
(length,) = struct.unpack_from('=L', args_payload, offset=offset)
|
|
offset += 4
|
|
s = args_payload[offset:offset+length]
|
|
offset += length
|
|
args.append(s)
|
|
else:
|
|
(value,) = struct.unpack_from('=Q', args_payload, offset=offset)
|
|
offset += 8
|
|
args.append(value)
|
|
|
|
yield (event_mapping[event_name], event_name, timestamp_ns, pid) + tuple(args)
|
|
|
|
class Analyzer:
|
|
"""[Deprecated. Refer to Analyzer2 instead.]
|
|
|
|
A trace file analyzer which processes trace records.
|
|
|
|
An analyzer can be passed to run() or process(). The begin() method is
|
|
invoked, then each trace record is processed, and finally the end() method
|
|
is invoked. When Analyzer is used as a context-manager (using the `with`
|
|
statement), begin() and end() are called automatically.
|
|
|
|
If a method matching a trace event name exists, it is invoked to process
|
|
that trace record. Otherwise the catchall() method is invoked.
|
|
|
|
Example:
|
|
The following method handles the runstate_set(int new_state) trace event::
|
|
|
|
def runstate_set(self, new_state):
|
|
...
|
|
|
|
The method can also take a timestamp argument before the trace event
|
|
arguments::
|
|
|
|
def runstate_set(self, timestamp, new_state):
|
|
...
|
|
|
|
Timestamps have the uint64_t type and are in nanoseconds.
|
|
|
|
The pid can be included in addition to the timestamp and is useful when
|
|
dealing with traces from multiple processes::
|
|
|
|
def runstate_set(self, timestamp, pid, new_state):
|
|
...
|
|
"""
|
|
|
|
def begin(self):
|
|
"""Called at the start of the trace."""
|
|
pass
|
|
|
|
def catchall(self, event, rec):
|
|
"""Called if no specific method for processing a trace event has been found."""
|
|
pass
|
|
|
|
def _build_fn(self, event):
|
|
fn = getattr(self, event.name, None)
|
|
if fn is None:
|
|
# Return early to avoid costly call to inspect.getfullargspec
|
|
return self.catchall
|
|
|
|
event_argcount = len(event.args)
|
|
fn_argcount = len(inspect.getfullargspec(fn)[0]) - 1
|
|
if fn_argcount == event_argcount + 1:
|
|
# Include timestamp as first argument
|
|
return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
|
|
elif fn_argcount == event_argcount + 2:
|
|
# Include timestamp and pid
|
|
return lambda _, rec: fn(*rec[1:3 + event_argcount])
|
|
else:
|
|
# Just arguments, no timestamp or pid
|
|
return lambda _, rec: fn(*rec[3:3 + event_argcount])
|
|
|
|
def _process_event(self, rec_args, *, event, event_id, timestamp_ns, pid, **kwargs):
|
|
warnings.warn(
|
|
"Use of deprecated Analyzer class. Refer to Analyzer2 instead.",
|
|
DeprecationWarning,
|
|
)
|
|
|
|
if not hasattr(self, '_fn_cache'):
|
|
# NOTE: Cannot depend on downstream subclasses to have
|
|
# super().__init__() because of legacy.
|
|
self._fn_cache = {}
|
|
|
|
rec = (event_id, timestamp_ns, pid, *rec_args)
|
|
if event_id not in self._fn_cache:
|
|
self._fn_cache[event_id] = self._build_fn(event)
|
|
self._fn_cache[event_id](event, rec)
|
|
|
|
def end(self):
|
|
"""Called at the end of the trace."""
|
|
pass
|
|
|
|
def __enter__(self):
|
|
self.begin()
|
|
return self
|
|
|
|
def __exit__(self, exc_type, exc_val, exc_tb):
|
|
if exc_type is None:
|
|
self.end()
|
|
return False
|
|
|
|
class Analyzer2(Analyzer):
|
|
"""A trace file analyzer which processes trace records.
|
|
|
|
An analyzer can be passed to run() or process(). The begin() method is
|
|
invoked, then each trace record is processed, and finally the end() method
|
|
is invoked. When Analyzer is used as a context-manager (using the `with`
|
|
statement), begin() and end() are called automatically.
|
|
|
|
If a method matching a trace event name exists, it is invoked to process
|
|
that trace record. Otherwise the catchall() method is invoked.
|
|
|
|
The methods are called with a set of keyword-arguments. These can be ignored
|
|
using `**kwargs` or defined like any keyword-argument.
|
|
|
|
The following keyword-arguments are available, but make sure to have an
|
|
**kwargs to allow for unmatched arguments in the future:
|
|
event: Event object of current trace
|
|
event_id: The id of the event in the current trace file
|
|
timestamp_ns: The timestamp in nanoseconds of the trace
|
|
pid: The process id recorded for the given trace
|
|
|
|
Example:
|
|
The following method handles the runstate_set(int new_state) trace event::
|
|
|
|
def runstate_set(self, new_state, **kwargs):
|
|
...
|
|
|
|
The method can also explicitly take a timestamp keyword-argument with the
|
|
trace event arguments::
|
|
|
|
def runstate_set(self, new_state, *, timestamp_ns, **kwargs):
|
|
...
|
|
|
|
Timestamps have the uint64_t type and are in nanoseconds.
|
|
|
|
The pid can be included in addition to the timestamp and is useful when
|
|
dealing with traces from multiple processes:
|
|
|
|
def runstate_set(self, new_state, *, timestamp_ns, pid, **kwargs):
|
|
...
|
|
"""
|
|
|
|
def catchall(self, *rec_args, event, timestamp_ns, pid, event_id, **kwargs):
|
|
"""Called if no specific method for processing a trace event has been found."""
|
|
pass
|
|
|
|
def _process_event(self, rec_args, *, event, **kwargs):
|
|
fn = getattr(self, event.name, self.catchall)
|
|
fn(*rec_args, event=event, **kwargs)
|
|
|
|
def process(events, log, analyzer, read_header=True):
|
|
"""Invoke an analyzer on each event in a log.
|
|
Args:
|
|
events (file-object or list or str): events list or file-like object or file path as str to read event data from
|
|
log (file-object or str): file-like object or file path as str to read log data from
|
|
analyzer (Analyzer): Instance of Analyzer to interpret the event data
|
|
read_header (bool, optional): Whether to read header data from the log data. Defaults to True.
|
|
"""
|
|
|
|
if isinstance(events, str):
|
|
with open(events, 'r') as f:
|
|
events_list = read_events(f, events)
|
|
elif isinstance(events, list):
|
|
# Treat as a list of events already produced by tracetool.read_events
|
|
events_list = events
|
|
else:
|
|
# Treat as an already opened file-object
|
|
events_list = read_events(events, events.name)
|
|
|
|
if isinstance(log, str):
|
|
with open(log, 'rb') as log_fobj:
|
|
_process(events_list, log_fobj, analyzer, read_header)
|
|
else:
|
|
# Treat `log` as an already opened file-object. We will not close it,
|
|
# as we do not own it.
|
|
_process(events_list, log, analyzer, read_header)
|
|
|
|
def _process(events, log_fobj, analyzer, read_header=True):
|
|
"""Internal function for processing
|
|
|
|
Args:
|
|
events (list): list of events already produced by tracetool.read_events
|
|
log_fobj (file): file-object to read log data from
|
|
analyzer (Analyzer): the Analyzer to interpret the event data
|
|
read_header (bool, optional): Whether to read header data from the log data. Defaults to True.
|
|
"""
|
|
|
|
if read_header:
|
|
read_trace_header(log_fobj)
|
|
|
|
with analyzer:
|
|
for event, event_id, timestamp_ns, record_pid, *rec_args in read_trace_records(events, log_fobj, read_header):
|
|
analyzer._process_event(
|
|
rec_args,
|
|
event=event,
|
|
event_id=event_id,
|
|
timestamp_ns=timestamp_ns,
|
|
pid=record_pid,
|
|
)
|
|
|
|
def run(analyzer):
|
|
"""Execute an analyzer on a trace file given on the command-line.
|
|
|
|
This function is useful as a driver for simple analysis scripts. More
|
|
advanced scripts will want to call process() instead."""
|
|
|
|
try:
|
|
# NOTE: See built-in `argparse` module for a more robust cli interface
|
|
*no_header, trace_event_path, trace_file_path = sys.argv[1:]
|
|
assert no_header == [] or no_header == ['--no-header'], 'Invalid no-header argument'
|
|
except (AssertionError, ValueError):
|
|
raise SimpleException(f'usage: {sys.argv[0]} [--no-header] <trace-events> <trace-file>\n')
|
|
|
|
with open(trace_event_path, 'r') as events_fobj, open(trace_file_path, 'rb') as log_fobj:
|
|
process(events_fobj, log_fobj, analyzer, read_header=not no_header)
|
|
|
|
if __name__ == '__main__':
|
|
class Formatter2(Analyzer2):
|
|
def __init__(self):
|
|
self.last_timestamp_ns = None
|
|
|
|
def catchall(self, *rec_args, event, timestamp_ns, pid, event_id):
|
|
if self.last_timestamp_ns is None:
|
|
self.last_timestamp_ns = timestamp_ns
|
|
delta_ns = timestamp_ns - self.last_timestamp_ns
|
|
self.last_timestamp_ns = timestamp_ns
|
|
|
|
fields = [
|
|
f'{name}={r}' if is_string(type) else f'{name}=0x{r:x}'
|
|
for r, (type, name) in zip(rec_args, event.args)
|
|
]
|
|
print(f'{event.name} {delta_ns / 1000:0.3f} {pid=} ' + ' '.join(fields))
|
|
|
|
try:
|
|
run(Formatter2())
|
|
except SimpleException as e:
|
|
sys.stderr.write(str(e) + "\n")
|
|
sys.exit(1)
|