#!/usr/bin/env python3
# -*- python -*-
#
# Copyright (C) 2019 Red Hat, Inc
#
# QEMU SystemTap Trace Tool
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, see <http://www.gnu.org/licenses/>.
import argparse
import copy
import os.path
import re
import subprocess
import sys
def probe_prefix(binary):
dirname, filename = os.path.split(binary)
return re.sub("-", ".", filename) + ".log"
def which(binary):
for path in os.environ["PATH"].split(os.pathsep):
if os.path.exists(os.path.join(path, binary)):
return os.path.join(path, binary)
print("Unable to find '%s' in $PATH" % binary)
sys.exit(1)
def tapset_dir(binary):
dirname, filename = os.path.split(binary)
if dirname == '':
thisfile = which(binary)
else:
thisfile = os.path.realpath(binary)
if not os.path.exists(thisfile):
print("Unable to find '%s'" % thisfile)
sys.exit(1)
basedir = os.path.split(thisfile)[0]
tapset = os.path.join(basedir, "..", "share", "systemtap", "tapset")
return os.path.realpath(tapset)
def cmd_run(args):
prefix = probe_prefix(args.binary)
tapsets = tapset_dir(args.binary)
if args.verbose:
print("Using tapset dir '%s' for binary '%s'" % (tapsets, args.binary))
probes = []
for probe in args.probes:
probes.append("probe %s.%s {}" % (prefix, probe))
if len(probes) == 0:
print("At least one probe pattern must be specified")
sys.exit(1)
script = " ".join(probes)
if args.verbose:
print("Compiling script '%s'" % script)
script = """probe begin { print("Running script, <Ctrl>-c to quit\\n") } """ + script
# We request an 8MB buffer, since the stap default 1MB buffer
# can be easily overflowed by frequently firing QEMU traces
stapargs = ["stap", "-s", "8", "-I", tapsets ]
if args.pid is not None:
stapargs.extend(["-x", args.pid])
stapargs.extend(["-e", script])
subprocess.call(stapargs)
def cmd_list(args):
tapsets = tapset_dir(args.binary)
if args.verbose:
print("Using tapset dir '%s' for binary '%s'" % (tapsets, args.binary))
def print_probes(verbose, name):
prefix = probe_prefix(args.binary)
offset = len(prefix) + 1
script = prefix + "." + name
if verbose:
print("Listing probes with name '%s'" % script)
proc = subprocess.Popen(["stap", "-I", tapsets, "-l", script],
stdout=subprocess.PIPE,
universal_newlines=True)
out, err = proc.communicate()
if proc.returncode != 0:
print("No probes found, are the tapsets installed in %s" % tapset_dir(args.binary))
sys.exit(1)
for line in out.splitlines():
if line.startswith(prefix):
print("%s" % line[offset:])
if len(args.probes) == 0:
print_probes(args.verbose, "*")
else:
for probe in args.probes:
print_probes(args.verbose, probe)
def main():
parser = argparse.ArgumentParser(description="QEMU SystemTap trace tool")
parser.add_argument("-v", "--verbose", help="Print verbose progress info",
action='store_true')
subparser = parser.add_subparsers(help="commands")
subparser.required = True
subparser.dest = "command"
runparser = subparser.add_parser("run", help="Run a trace session",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog="""
To watch all trace points on the qemu-system-x86_64 binary:
%(argv0)s run qemu-system-x86_64
To only watch the trace points matching the qio* and qcrypto* patterns
%(argv0)s run qemu-system-x86_64 'qio*' 'qcrypto*'
""" % {"argv0": sys.argv[0]})
runparser.set_defaults(func=cmd_run)
runparser.add_argument("--pid", "-p", dest="pid",
help="Restrict tracing to a specific process ID")
runparser.add_argument("binary", help="QEMU system or user emulator binary")
runparser.add_argument("probes", help="Probe names or wildcards",
nargs=argparse.REMAINDER)
listparser = subparser.add_parser("list", help="List probe points",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog="""
To list all trace points on the qemu-system-x86_64 binary:
%(argv0)s list qemu-system-x86_64
To only list the trace points matching the qio* and qcrypto* patterns
%(argv0)s list qemu-system-x86_64 'qio*' 'qcrypto*'
""" % {"argv0": sys.argv[0]})
listparser.set_defaults(func=cmd_list)
listparser.add_argument("binary", help="QEMU system or user emulator binary")
listparser.add_argument("probes", help="Probe names or wildcards",
nargs=argparse.REMAINDER)
args = parser.parse_args()
args.func(args)
sys.exit(0)
if __name__ == '__main__':
main()
