QEMU SystemTap trace tool — QEMU documentation

# 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

The following global options may be used regardless of which command is executed:

--verbose, -v

  Display verbose information about command execution.

The following commands are valid:

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/7.2.22/bin/qemu-system-x86_64 'qcrypto*'

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:

  --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/7.2.22/bin/qemu-system-x86_64 'qio*'

## See also

qemu(1), stap(1)