diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | Makefile | 10 | ||||
| -rw-r--r-- | Makefile.target | 11 | ||||
| -rw-r--r-- | docs/devel/tracing.txt | 4 | ||||
| -rwxr-xr-x | scripts/qemu-trace-stap | 175 | ||||
| -rw-r--r-- | scripts/qemu-trace-stap.texi | 140 | ||||
| -rw-r--r-- | scripts/tracetool/format/log_stap.py | 127 |
7 files changed, 467 insertions, 1 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index af339b86db..efa42c79fe 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2017,6 +2017,7 @@ F: trace-events F: qemu-option-trace.texi F: scripts/tracetool.py F: scripts/tracetool/ +F: scripts/qemu-trace-stap* F: docs/devel/tracing.txt T: git https://github.com/stefanha/qemu.git tracing @@ -305,6 +305,9 @@ DOCS+=docs/qemu-cpu-models.7 ifdef CONFIG_VIRTFS DOCS+=fsdev/virtfs-proxy-helper.1 endif +ifdef CONFIG_TRACE_SYSTEMTAP +DOCS+=scripts/qemu-trace-stap.1 +endif else DOCS= endif @@ -699,6 +702,9 @@ ifneq ($(TOOLS),) $(INSTALL_DIR) "$(DESTDIR)$(mandir)/man8" $(INSTALL_DATA) qemu-nbd.8 "$(DESTDIR)$(mandir)/man8" endif +ifdef CONFIG_TRACE_SYSTEMTAP + $(INSTALL_DATA) scripts/qemu-trace-stap.1 "$(DESTDIR)$(mandir)/man1" +endif ifneq (,$(findstring qemu-ga,$(TOOLS))) $(INSTALL_DATA) qemu-ga.8 "$(DESTDIR)$(mandir)/man8" $(INSTALL_DATA) docs/interop/qemu-ga-ref.html "$(DESTDIR)$(qemu_docdir)" @@ -738,6 +744,9 @@ endif ifneq ($(HELPERS-y),) $(call install-prog,$(HELPERS-y),$(DESTDIR)$(libexecdir)) endif +ifdef CONFIG_TRACE_SYSTEMTAP + $(INSTALL_PROG) "scripts/qemu-trace-stap" $(DESTDIR)$(bindir) +endif ifneq ($(BLOBS),) set -e; for x in $(BLOBS); do \ $(INSTALL_DATA) $(SRC_PATH)/pc-bios/$$x "$(DESTDIR)$(qemu_datadir)"; \ @@ -852,6 +861,7 @@ qemu-nbd.8: qemu-nbd.texi qemu-option-trace.texi qemu-ga.8: qemu-ga.texi docs/qemu-block-drivers.7: docs/qemu-block-drivers.texi docs/qemu-cpu-models.7: docs/qemu-cpu-models.texi +scripts/qemu-trace-stap.1: scripts/qemu-trace-stap.texi html: qemu-doc.html docs/interop/qemu-qmp-ref.html docs/interop/qemu-ga-ref.html info: qemu-doc.info docs/interop/qemu-qmp-ref.info docs/interop/qemu-ga-ref.info diff --git a/Makefile.target b/Makefile.target index 39f72e81be..401dc1ea6f 100644 --- a/Makefile.target +++ b/Makefile.target @@ -45,7 +45,7 @@ config-target.h: config-target.h-timestamp config-target.h-timestamp: config-target.mak ifdef CONFIG_TRACE_SYSTEMTAP -stap: $(QEMU_PROG).stp-installed $(QEMU_PROG).stp $(QEMU_PROG)-simpletrace.stp +stap: $(QEMU_PROG).stp-installed $(QEMU_PROG).stp $(QEMU_PROG)-simpletrace.stp $(QEMU_PROG)-log.stp ifdef CONFIG_USER_ONLY TARGET_TYPE=user @@ -84,6 +84,14 @@ $(QEMU_PROG)-simpletrace.stp: $(BUILD_DIR)/trace-events-all $(tracetool-y) --probe-prefix=qemu.$(TARGET_TYPE).$(TARGET_NAME) \ $< > $@,"GEN","$(TARGET_DIR)$(QEMU_PROG)-simpletrace.stp") +$(QEMU_PROG)-log.stp: $(BUILD_DIR)/trace-events-all $(tracetool-y) + $(call quiet-command,$(TRACETOOL) \ + --group=all \ + --format=log-stap \ + --backends=$(TRACE_BACKENDS) \ + --probe-prefix=qemu.$(TARGET_TYPE).$(TARGET_NAME) \ + $< > $@,"GEN","$(TARGET_DIR)$(QEMU_PROG)-log.stp") + else stap: endif @@ -227,6 +235,7 @@ ifdef CONFIG_TRACE_SYSTEMTAP $(INSTALL_DIR) "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset" $(INSTALL_DATA) $(QEMU_PROG).stp-installed "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset/$(QEMU_PROG).stp" $(INSTALL_DATA) $(QEMU_PROG)-simpletrace.stp "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset/$(QEMU_PROG)-simpletrace.stp" + $(INSTALL_DATA) $(QEMU_PROG)-log.stp "$(DESTDIR)$(qemu_datadir)/../systemtap/tapset/$(QEMU_PROG)-log.stp" endif GENERATED_FILES += config-target.h diff --git a/docs/devel/tracing.txt b/docs/devel/tracing.txt index bc52f12485..056aa56496 100644 --- a/docs/devel/tracing.txt +++ b/docs/devel/tracing.txt @@ -317,6 +317,10 @@ probes: --target-name x86_64 \ <trace-events-all >qemu.stp +To facilitate simple usage of systemtap where there merely needs to be printf +logging of certain probes, a helper script "qemu-trace-stap" is provided. +Consult its manual page for guidance on its usage. + == Trace event properties == Each event in the "trace-events-all" file can be prefixed with a space-separated diff --git a/scripts/qemu-trace-stap b/scripts/qemu-trace-stap new file mode 100755 index 0000000000..91d1051cdc --- /dev/null +++ b/scripts/qemu-trace-stap @@ -0,0 +1,175 @@ +#!/usr/bin/python +# -*- 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/>. + +from __future__ import print_function + +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 tapset_env(tapset_dir): + tenv = copy.copy(os.environ) + tenv["SYSTEMTAP_TAPSET"] = tapset_dir + return tenv + +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"] + if args.pid is not None: + stapargs.extend(["-x", args.pid]) + stapargs.extend(["-e", script]) + subprocess.call(stapargs, env=tapset_env(tapsets)) + + +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", "-l", script], + stdout=subprocess.PIPE, env=tapset_env(tapsets)) + 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() diff --git a/scripts/qemu-trace-stap.texi b/scripts/qemu-trace-stap.texi new file mode 100644 index 0000000000..07bb9eb94e --- /dev/null +++ b/scripts/qemu-trace-stap.texi @@ -0,0 +1,140 @@ +@example +@c man begin SYNOPSIS +@command{qemu-trace-stap} @var{GLOBAL-OPTIONS} @var{COMMAND} @var{COMMAND-OPTIONS} @var{ARGS...} +@c man end +@end example + +@c man begin DESCRIPTION + +The @command{qemu-trace-stap} program facilitates tracing of the execution +of QEMU emulators using SystemTap. + +It is required to have the SystemTap runtime environment installed to use +this program, since it is a wrapper around execution of the @command{stap} +program. + +@c man end + +@c man begin OPTIONS + +The following global options may be used regardless of which command +is executed: + +@table @option +@item @var{--verbose}, @var{-v} + +Display verbose information about command execution. + +@end table + +The following commands are valid: + +@table @option + +@item @var{list} @var{BINARY} @var{PATTERN...} + +List all the probe names provided by @var{BINARY} that match +@var{PATTERN}. + +If @var{BINARY} is not an absolute path, it will be located by searching +the directories listed in the @code{$PATH} environment variable. + +@var{PATTERN} is a plain string that is used to filter the results of +this command. It may optionally contain a @code{*} wildcard to facilitate +matching multiple probes without listing each one explicitly. Multiple +@var{PATTERN} arguments may be given, causing listing of probes that match +any of the listed names. If no @var{PATTERN} is given, the all possible +probes will be listed. + +For example, to list all probes available in the @command{qemu-system-x86_64} +binary: + +@example +$ qemu-trace-stap list qemu-system-x86_64 +@end example + +To filter the list to only cover probes related to QEMU's cryptographic +subsystem, in a binary outside @code{$PATH} + +@example +$ qemu-trace-stap list /opt/qemu/4.0.0/bin/qemu-system-x86_64 'qcrypto*' +@end example + + +@item @var{run} @var{OPTIONS} @var{BINARY} @var{PATTERN...} + +Run a trace session, printing formatted output any time a process that is +executing @var{BINARY} triggers a probe matching @var{PATTERN}. + +If @var{BINARY} is not an absolute path, it will be located by searching +the directories listed in the @code{$PATH} environment variable. + +@var{PATTERN} is a plain string that matches a probe name shown by the +@var{list} command. It may optionally contain a @code{*} wildcard to +facilitate matching multiple probes without listing each one explicitly. +Multiple @var{PATTERN} arguments may be given, causing all matching probes +to be monitored. At least one @var{PATTERN} is required, since stap is not +capable of tracing all known QEMU probes concurrently without overflowing +its trace buffer. + +Invocation of this command does not need to be synchronized with +invocation of the QEMU process(es). It will match probes on all +existing running processes and all future launched processes, +unless told to only monitor a specific process. + +Valid command specific options are: + +@table @option +@item @var{--pid=PID}, @var{-p PID} + +Restrict the tracing session so that it only triggers for the process +identified by @code{PID}. + +@end table + +For example, to monitor all processes executing @command{qemu-system-x86_64} +as found on $PATH, displaying all I/O related probes: + +@example +$ qemu-trace-stap run qemu-system-x86_64 'qio*' +@end example + +To monitor only the QEMU process with PID 1732 + +@example +$ qemu-trace-stap run --pid=1732 qemu-system-x86_64 'qio*' +@end example + +To monitor QEMU processes running an alternative binary outside of +@code{$PATH}, displaying verbose information about setup of the +tracing environment: + +@example +$ qemu-trace-stap -v run /opt/qemu/4.0.0/qemu-system-x86_64 'qio*' +@end example + +@end table + +@c man end + +@ignore + +@setfilename qemu-trace-stap +@settitle QEMU SystemTap trace tool + +@c man begin LICENSE + +Copyright (C) 2019 Red Hat, Inc. + +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. + +@c man end + +@c man begin SEEALSO +qemu(1), stap(1) +@c man end + +@end ignore diff --git a/scripts/tracetool/format/log_stap.py b/scripts/tracetool/format/log_stap.py new file mode 100644 index 0000000000..3ccbc09d61 --- /dev/null +++ b/scripts/tracetool/format/log_stap.py @@ -0,0 +1,127 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +""" +Generate .stp file that printfs log messages (DTrace with SystemTAP only). +""" + +__author__ = "Daniel P. Berrange <berrange@redhat.com>" +__copyright__ = "Copyright (C) 2014-2019, Red Hat, Inc." +__license__ = "GPL version 2 or (at your option) any later version" + +__maintainer__ = "Daniel Berrange" +__email__ = "berrange@redhat.com" + +import re + +from tracetool import out +from tracetool.backend.dtrace import binary, probeprefix +from tracetool.backend.simple import is_string +from tracetool.format.stap import stap_escape + +def global_var_name(name): + return probeprefix().replace(".", "_") + "_" + name + +STATE_SKIP = 0 +STATE_LITERAL = 1 +STATE_MACRO = 2 + +def c_macro_to_format(macro): + if macro.startswith("PRI"): + return macro[3] + + if macro == "TARGET_FMT_plx": + return "%016x" + + raise Exception("Unhandled macro '%s'" % macro) + +def c_fmt_to_stap(fmt): + state = 0 + bits = [] + literal = "" + macro = "" + escape = 0; + for i in range(len(fmt)): + if fmt[i] == '\\': + if escape: + escape = 0 + else: + escape = 1 + if state != STATE_LITERAL: + raise Exception("Unexpected escape outside string literal") + literal = literal + fmt[i] + elif fmt[i] == '"' and not escape: + if state == STATE_LITERAL: + state = STATE_SKIP + bits.append(literal) + literal = "" + else: + if state == STATE_MACRO: + bits.append(c_macro_to_format(macro)) + state = STATE_LITERAL + elif fmt[i] == ' ' or fmt[i] == '\t': + if state == STATE_MACRO: + bits.append(c_macro_to_format(macro)) + macro = "" + state = STATE_SKIP + elif state == STATE_LITERAL: + literal = literal + fmt[i] + else: + escape = 0 + if state == STATE_SKIP: + state = STATE_MACRO + + if state == STATE_LITERAL: + literal = literal + fmt[i] + else: + macro = macro + fmt[i] + + if state == STATE_MACRO: + bits.append(c_macro_to_format(macro)) + elif state == STATE_LITERAL: + bits.append(literal) + + fmt = re.sub("%(\d*)z(x|u|d)", "%\\1\\2", "".join(bits)) + return fmt + +def generate(events, backend, group): + out('/* This file is autogenerated by tracetool, do not edit. */', + '') + + for event_id, e in enumerate(events): + if 'disable' in e.properties: + continue + + out('probe %(probeprefix)s.log.%(name)s = %(probeprefix)s.%(name)s ?', + '{', + probeprefix=probeprefix(), + name=e.name) + + # Get references to userspace strings + for type_, name in e.args: + name = stap_escape(name) + if is_string(type_): + out(' try {', + ' arg%(name)s_str = %(name)s ? ' + + 'user_string_n(%(name)s, 512) : "<null>"', + ' } catch {}', + name=name) + + # Determine systemtap's view of variable names + fields = ["pid()", "gettimeofday_ns()"] + for type_, name in e.args: + name = stap_escape(name) + if is_string(type_): + fields.append("arg" + name + "_str") + else: + fields.append(name) + + # Emit the entire record in a single SystemTap printf() + arg_str = ', '.join(arg for arg in fields) + fmt_str = "%d@%d " + e.name + " " + c_fmt_to_stap(e.fmt) + "\\n" + out(' printf("%(fmt_str)s", %(arg_str)s)', + fmt_str=fmt_str, arg_str=arg_str) + + out('}') + + out() |