xref: /openbmc/qemu/docs/tools/qemu-trace-stap.rst (revision 2f44bea9)
1=========================
2QEMU SystemTap trace tool
3=========================
4
5Synopsis
6--------
7
8**qemu-trace-stap** [*GLOBAL-OPTIONS*] *COMMAND* [*COMMAND-OPTIONS*] *ARGS*...
9
10Description
11-----------
12
13The ``qemu-trace-stap`` program facilitates tracing of the execution
14of QEMU emulators using SystemTap.
15
16It is required to have the SystemTap runtime environment installed to use
17this program, since it is a wrapper around execution of the ``stap``
18program.
19
20Options
21-------
22
23.. program:: qemu-trace-stap
24
25The following global options may be used regardless of which command
26is executed:
27
28.. option:: --verbose, -v
29
30  Display verbose information about command execution.
31
32The following commands are valid:
33
34.. option:: list BINARY PATTERN...
35
36  List all the probe names provided by *BINARY* that match
37  *PATTERN*.
38
39  If *BINARY* is not an absolute path, it will be located by searching
40  the directories listed in the ``$PATH`` environment variable.
41
42  *PATTERN* is a plain string that is used to filter the results of
43  this command. It may optionally contain a ``*`` wildcard to facilitate
44  matching multiple probes without listing each one explicitly. Multiple
45  *PATTERN* arguments may be given, causing listing of probes that match
46  any of the listed names. If no *PATTERN* is given, the all possible
47  probes will be listed.
48
49  For example, to list all probes available in the ``qemu-system-x86_64``
50  binary:
51
52  ::
53
54    $ qemu-trace-stap list qemu-system-x86_64
55
56  To filter the list to only cover probes related to QEMU's cryptographic
57  subsystem, in a binary outside ``$PATH``
58
59  ::
60
61    $ qemu-trace-stap list /opt/qemu/4.0.0/bin/qemu-system-x86_64 'qcrypto*'
62
63.. option:: run OPTIONS BINARY PATTERN...
64
65  Run a trace session, printing formatted output any time a process that is
66  executing *BINARY* triggers a probe matching *PATTERN*.
67
68  If *BINARY* is not an absolute path, it will be located by searching
69  the directories listed in the ``$PATH`` environment variable.
70
71  *PATTERN* is a plain string that matches a probe name shown by the
72  *LIST* command. It may optionally contain a ``*`` wildcard to
73  facilitate matching multiple probes without listing each one explicitly.
74  Multiple *PATTERN* arguments may be given, causing all matching probes
75  to be monitored. At least one *PATTERN* is required, since stap is not
76  capable of tracing all known QEMU probes concurrently without overflowing
77  its trace buffer.
78
79  Invocation of this command does not need to be synchronized with
80  invocation of the QEMU process(es). It will match probes on all
81  existing running processes and all future launched processes,
82  unless told to only monitor a specific process.
83
84  Valid command specific options are:
85
86  .. program:: qemu-trace-stap-run
87
88  .. option:: --pid=PID, -p PID
89
90    Restrict the tracing session so that it only triggers for the process
91    identified by *PID*.
92
93  For example, to monitor all processes executing ``qemu-system-x86_64``
94  as found on ``$PATH``, displaying all I/O related probes:
95
96  ::
97
98    $ qemu-trace-stap run qemu-system-x86_64 'qio*'
99
100  To monitor only the QEMU process with PID 1732
101
102  ::
103
104    $ qemu-trace-stap run --pid=1732 qemu-system-x86_64 'qio*'
105
106  To monitor QEMU processes running an alternative binary outside of
107  ``$PATH``, displaying verbose information about setup of the
108  tracing environment:
109
110  ::
111
112    $ qemu-trace-stap -v run /opt/qemu/4.0.0/qemu-system-x86_64 'qio*'
113
114See also
115--------
116
117:manpage:`qemu(1)`, :manpage:`stap(1)`
118
119..
120  Copyright (C) 2019 Red Hat, Inc.
121
122  This program is free software; you can redistribute it and/or modify
123  it under the terms of the GNU General Public License as published by
124  the Free Software Foundation; either version 2 of the License, or
125  (at your option) any later version.
126