xref: /openbmc/qemu/docs/tools/qemu-trace-stap.rst (revision 250bc43a)
1QEMU SystemTap trace tool
2=========================
3
4Synopsis
5--------
6
7**qemu-trace-stap** [*GLOBAL-OPTIONS*] *COMMAND* [*COMMAND-OPTIONS*] *ARGS*...
8
9Description
10-----------
11
12The ``qemu-trace-stap`` program facilitates tracing of the execution
13of QEMU emulators using SystemTap.
14
15It is required to have the SystemTap runtime environment installed to use
16this program, since it is a wrapper around execution of the ``stap``
17program.
18
19Options
20-------
21
22.. program:: qemu-trace-stap
23
24The following global options may be used regardless of which command
25is executed:
26
27.. option:: --verbose, -v
28
29  Display verbose information about command execution.
30
31The following commands are valid:
32
33.. option:: list BINARY PATTERN...
34
35  List all the probe names provided by *BINARY* that match
36  *PATTERN*.
37
38  If *BINARY* is not an absolute path, it will be located by searching
39  the directories listed in the ``$PATH`` environment variable.
40
41  *PATTERN* is a plain string that is used to filter the results of
42  this command. It may optionally contain a ``*`` wildcard to facilitate
43  matching multiple probes without listing each one explicitly. Multiple
44  *PATTERN* arguments may be given, causing listing of probes that match
45  any of the listed names. If no *PATTERN* is given, the all possible
46  probes will be listed.
47
48  For example, to list all probes available in the ``qemu-system-x86_64``
49  binary:
50
51  ::
52
53    $ qemu-trace-stap list qemu-system-x86_64
54
55  To filter the list to only cover probes related to QEMU's cryptographic
56  subsystem, in a binary outside ``$PATH``
57
58  ::
59
60    $ qemu-trace-stap list /opt/qemu/4.0.0/bin/qemu-system-x86_64 'qcrypto*'
61
62.. option:: run OPTIONS BINARY PATTERN...
63
64  Run a trace session, printing formatted output any time a process that is
65  executing *BINARY* triggers a probe matching *PATTERN*.
66
67  If *BINARY* is not an absolute path, it will be located by searching
68  the directories listed in the ``$PATH`` environment variable.
69
70  *PATTERN* is a plain string that matches a probe name shown by the
71  *LIST* command. It may optionally contain a ``*`` wildcard to
72  facilitate matching multiple probes without listing each one explicitly.
73  Multiple *PATTERN* arguments may be given, causing all matching probes
74  to be monitored. At least one *PATTERN* is required, since stap is not
75  capable of tracing all known QEMU probes concurrently without overflowing
76  its trace buffer.
77
78  Invocation of this command does not need to be synchronized with
79  invocation of the QEMU process(es). It will match probes on all
80  existing running processes and all future launched processes,
81  unless told to only monitor a specific process.
82
83  Valid command specific options are:
84
85  .. program:: qemu-trace-stap-run
86
87  .. option:: --pid=PID, -p PID
88
89    Restrict the tracing session so that it only triggers for the process
90    identified by *PID*.
91
92  For example, to monitor all processes executing ``qemu-system-x86_64``
93  as found on ``$PATH``, displaying all I/O related probes:
94
95  ::
96
97    $ qemu-trace-stap run qemu-system-x86_64 'qio*'
98
99  To monitor only the QEMU process with PID 1732
100
101  ::
102
103    $ qemu-trace-stap run --pid=1732 qemu-system-x86_64 'qio*'
104
105  To monitor QEMU processes running an alternative binary outside of
106  ``$PATH``, displaying verbose information about setup of the
107  tracing environment:
108
109  ::
110
111    $ qemu-trace-stap -v run /opt/qemu/4.0.0/qemu-system-x86_64 'qio*'
112
113See also
114--------
115
116:manpage:`qemu(1)`, :manpage:`stap(1)`
117
118..
119  Copyright (C) 2019 Red Hat, Inc.
120
121  This program is free software; you can redistribute it and/or modify
122  it under the terms of the GNU General Public License as published by
123  the Free Software Foundation; either version 2 of the License, or
124  (at your option) any later version.
125