qemu-trace-stap (5623B)
1 #!/usr/bin/env python3 2 # -*- python -*- 3 # 4 # Copyright (C) 2019 Red Hat, Inc 5 # 6 # QEMU SystemTap Trace Tool 7 # 8 # This program is free software; you can redistribute it and/or modify 9 # it under the terms of the GNU General Public License as published by 10 # the Free Software Foundation; either version 2 of the License, or 11 # (at your option) any later version. 12 # 13 # This program is distributed in the hope that it will be useful, 14 # but WITHOUT ANY WARRANTY; without even the implied warranty of 15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 # GNU General Public License for more details. 17 # 18 # You should have received a copy of the GNU General Public License 19 # along with this program; if not, see <http://www.gnu.org/licenses/>. 20 21 import argparse 22 import copy 23 import os.path 24 import re 25 import subprocess 26 import sys 27 28 29 def probe_prefix(binary): 30 dirname, filename = os.path.split(binary) 31 return re.sub("-", ".", filename) + ".log" 32 33 34 def which(binary): 35 for path in os.environ["PATH"].split(os.pathsep): 36 if os.path.exists(os.path.join(path, binary)): 37 return os.path.join(path, binary) 38 39 print("Unable to find '%s' in $PATH" % binary) 40 sys.exit(1) 41 42 43 def tapset_dir(binary): 44 dirname, filename = os.path.split(binary) 45 if dirname == '': 46 thisfile = which(binary) 47 else: 48 thisfile = os.path.realpath(binary) 49 if not os.path.exists(thisfile): 50 print("Unable to find '%s'" % thisfile) 51 sys.exit(1) 52 53 basedir = os.path.split(thisfile)[0] 54 tapset = os.path.join(basedir, "..", "share", "systemtap", "tapset") 55 return os.path.realpath(tapset) 56 57 58 def cmd_run(args): 59 prefix = probe_prefix(args.binary) 60 tapsets = tapset_dir(args.binary) 61 62 if args.verbose: 63 print("Using tapset dir '%s' for binary '%s'" % (tapsets, args.binary)) 64 65 probes = [] 66 for probe in args.probes: 67 probes.append("probe %s.%s {}" % (prefix, probe)) 68 if len(probes) == 0: 69 print("At least one probe pattern must be specified") 70 sys.exit(1) 71 72 script = " ".join(probes) 73 if args.verbose: 74 print("Compiling script '%s'" % script) 75 script = """probe begin { print("Running script, <Ctrl>-c to quit\\n") } """ + script 76 77 # We request an 8MB buffer, since the stap default 1MB buffer 78 # can be easily overflowed by frequently firing QEMU traces 79 stapargs = ["stap", "-s", "8", "-I", tapsets ] 80 if args.pid is not None: 81 stapargs.extend(["-x", args.pid]) 82 stapargs.extend(["-e", script]) 83 subprocess.call(stapargs) 84 85 86 def cmd_list(args): 87 tapsets = tapset_dir(args.binary) 88 89 if args.verbose: 90 print("Using tapset dir '%s' for binary '%s'" % (tapsets, args.binary)) 91 92 def print_probes(verbose, name): 93 prefix = probe_prefix(args.binary) 94 offset = len(prefix) + 1 95 script = prefix + "." + name 96 97 if verbose: 98 print("Listing probes with name '%s'" % script) 99 proc = subprocess.Popen(["stap", "-I", tapsets, "-l", script], 100 stdout=subprocess.PIPE, 101 universal_newlines=True) 102 out, err = proc.communicate() 103 if proc.returncode != 0: 104 print("No probes found, are the tapsets installed in %s" % tapset_dir(args.binary)) 105 sys.exit(1) 106 107 for line in out.splitlines(): 108 if line.startswith(prefix): 109 print("%s" % line[offset:]) 110 111 if len(args.probes) == 0: 112 print_probes(args.verbose, "*") 113 else: 114 for probe in args.probes: 115 print_probes(args.verbose, probe) 116 117 118 def main(): 119 parser = argparse.ArgumentParser(description="QEMU SystemTap trace tool") 120 parser.add_argument("-v", "--verbose", help="Print verbose progress info", 121 action='store_true') 122 123 subparser = parser.add_subparsers(help="commands") 124 subparser.required = True 125 subparser.dest = "command" 126 127 runparser = subparser.add_parser("run", help="Run a trace session", 128 formatter_class=argparse.RawDescriptionHelpFormatter, 129 epilog=""" 130 131 To watch all trace points on the qemu-system-x86_64 binary: 132 133 %(argv0)s run qemu-system-x86_64 134 135 To only watch the trace points matching the qio* and qcrypto* patterns 136 137 %(argv0)s run qemu-system-x86_64 'qio*' 'qcrypto*' 138 """ % {"argv0": sys.argv[0]}) 139 runparser.set_defaults(func=cmd_run) 140 runparser.add_argument("--pid", "-p", dest="pid", 141 help="Restrict tracing to a specific process ID") 142 runparser.add_argument("binary", help="QEMU system or user emulator binary") 143 runparser.add_argument("probes", help="Probe names or wildcards", 144 nargs=argparse.REMAINDER) 145 146 listparser = subparser.add_parser("list", help="List probe points", 147 formatter_class=argparse.RawDescriptionHelpFormatter, 148 epilog=""" 149 150 To list all trace points on the qemu-system-x86_64 binary: 151 152 %(argv0)s list qemu-system-x86_64 153 154 To only list the trace points matching the qio* and qcrypto* patterns 155 156 %(argv0)s list qemu-system-x86_64 'qio*' 'qcrypto*' 157 """ % {"argv0": sys.argv[0]}) 158 listparser.set_defaults(func=cmd_list) 159 listparser.add_argument("binary", help="QEMU system or user emulator binary") 160 listparser.add_argument("probes", help="Probe names or wildcards", 161 nargs=argparse.REMAINDER) 162 163 args = parser.parse_args() 164 165 args.func(args) 166 sys.exit(0) 167 168 if __name__ == '__main__': 169 main()