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diff --git a/docs/interop/qemu-trace-stap.rst b/docs/interop/qemu-trace-stap.rst new file mode 100644 index 0000000000..fb70445c75 --- /dev/null +++ b/docs/interop/qemu-trace-stap.rst @@ -0,0 +1,124 @@ +QEMU SystemTap trace tool +========================= + +Synopsis +-------- + +**qemu-trace-stap** [*GLOBAL-OPTIONS*] *COMMAND* [*COMMAND-OPTIONS*] *ARGS*... + +Description +----------- + +The ``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 ``stap`` +program. + +Options +------- + +.. program:: qemu-trace-stap + +The following global options may be used regardless of which command +is executed: + +.. option:: --verbose, -v + + Display verbose information about command execution. + +The following commands are valid: + +.. option:: list BINARY PATTERN... + + List all the probe names provided by *BINARY* that match + *PATTERN*. + + If *BINARY* is not an absolute path, it will be located by searching + the directories listed in the ``$PATH`` environment variable. + + *PATTERN* is a plain string that is used to filter the results of + this command. It may optionally contain a ``*`` wildcard to facilitate + matching multiple probes without listing each one explicitly. Multiple + *PATTERN* arguments may be given, causing listing of probes that match + any of the listed names. If no *PATTERN* is given, the all possible + probes will be listed. + + For example, to list all probes available in the ``qemu-system-x86_64`` + binary: + + :: + + $ qemu-trace-stap list qemu-system-x86_64 + + To filter the list to only cover probes related to QEMU's cryptographic + subsystem, in a binary outside ``$PATH`` + + :: + + $ qemu-trace-stap list /opt/qemu/4.0.0/bin/qemu-system-x86_64 'qcrypto*' + +.. option:: run OPTIONS BINARY PATTERN... + + Run a trace session, printing formatted output any time a process that is + executing *BINARY* triggers a probe matching *PATTERN*. + + If *BINARY* is not an absolute path, it will be located by searching + the directories listed in the ``$PATH`` environment variable. + + *PATTERN* is a plain string that matches a probe name shown by the + *LIST* command. It may optionally contain a ``*`` wildcard to + facilitate matching multiple probes without listing each one explicitly. + Multiple *PATTERN* arguments may be given, causing all matching probes + to be monitored. At least one *PATTERN* is required, since stap is not + capable of tracing all known QEMU probes concurrently without overflowing + its trace buffer. + + Invocation of this command does not need to be synchronized with + invocation of the QEMU process(es). It will match probes on all + existing running processes and all future launched processes, + unless told to only monitor a specific process. + + Valid command specific options are: + + .. program:: qemu-trace-stap-run + + .. option:: --pid=PID, -p PID + + Restrict the tracing session so that it only triggers for the process + identified by *PID*. + + For example, to monitor all processes executing ``qemu-system-x86_64`` + as found on ``$PATH``, displaying all I/O related probes: + + :: + + $ qemu-trace-stap run qemu-system-x86_64 'qio*' + + To monitor only the QEMU process with PID 1732 + + :: + + $ qemu-trace-stap run --pid=1732 qemu-system-x86_64 'qio*' + + To monitor QEMU processes running an alternative binary outside of + ``$PATH``, displaying verbose information about setup of the + tracing environment: + + :: + + $ qemu-trace-stap -v run /opt/qemu/4.0.0/qemu-system-x86_64 'qio*' + +See also +-------- + +:manpage:`qemu(1)`, :manpage:`stap(1)` + +.. + 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. |