7.42. VBoxManage debugvm

Introspection and guest debugging.

7.42.1. Synopsis

VBoxManage debugvm { uuid|vmname } dumpvmcore [--filename=name]

VBoxManage debugvm { uuid|vmname } info { item } [ args ...]

VBoxManage debugvm { uuid|vmname } injectnmi

VBoxManage debugvm { uuid|vmname } log [[--release] | [--debug]] [ group-settings ...]

VBoxManage debugvm { uuid|vmname } logdest [[--release] | [--debug]] [ destinations ...]

VBoxManage debugvm { uuid|vmname } logflags [[--release] | [--debug]] [ flags ...]

VBoxManage debugvm { uuid|vmname } osdetect

VBoxManage debugvm { uuid|vmname } osinfo

VBoxManage debugvm { uuid|vmname } osdmesg [--lines=lines]

VBoxManage debugvm { uuid|vmname } getregisters [--cpu=id] [ reg-set.reg-name ...]

VBoxManage debugvm { uuid|vmname } setregisters [--cpu=id] [ reg-set.reg-name=value ...]

VBoxManage debugvm { uuid|vmname } show [[--human-readable] | [--sh-export] | [--sh-eval] | [--cmd-set]] [ settings-item ...]

VBoxManage debugvm { uuid|vmname } stack [--cpu=id]

VBoxManage debugvm { uuid|vmname } statistics [--reset] [--descriptions] [--pattern=pattern]

7.42.2. Description

The "debugvm" commands are for experts who want to tinker with the exact details of virtual machine execution. Like the VM debugger described in The Built-In VM Debugger, these commands are only useful if you are very familiar with the details of the PC architecture and how to debug software.

7.42.2.1. Common options

The subcommands of debugvm all operate on a running virtual machine:

uuid|vmname

Either the UUID or the name (case sensitive) of a VM.

7.42.2.2. debugvm dumpvmcore

VBoxManage debugvm { uuid|vmname } dumpvmcore [--filename=name]

Creates a system dump file of the specified VM. This file will have the standard ELF core format (with custom sections); see VM Core Format.

This corresponds to the writecore command in the debugger.

--filename=filename

The name of the output file.

7.42.2.3. debugvm info

VBoxManage debugvm { uuid|vmname } info { item } [ args ...]

Displays info items relating to the VMM, device emulations and associated drivers.

This corresponds to the info command in the debugger.

info

Name of the info item to display. The special name help will list all the available info items and hints about optional arguments.

args

Optional argument string for the info item handler. Most info items does not take any extra arguments. Arguments not recognized are generally ignored.

7.42.2.4. debugvm injectnmi

VBoxManage debugvm { uuid|vmname } injectnmi

Causes a non-maskable interrupt (NMI) to be injected into the guest. This might be useful for certain debugging scenarios. What happens exactly is dependent on the guest operating system, but an NMI can crash the whole guest operating system. Do not use unless you know what you're doing.

7.42.2.5. debugvm log

VBoxManage debugvm { uuid|vmname } log [[--release] | [--debug]] [ group-settings ...]

Changes the group settings for either debug (--debug) or release (--release) logger of the VM process.

The group-settings are typically strings on the form em.e.f.l, hm=~0 and -em.f. Basic wildcards are supported for group matching. The all group is an alias for all the groups.

Please do keep in mind that the group settings are applied as modifications to the current ones.

This corresponds to the log command in the debugger.

7.42.2.6. debugvm logdest

VBoxManage debugvm { uuid|vmname } logdest [[--release] | [--debug]] [ destinations ...]

Changes the destination settings for either debug (--debug) or release (--release) logger of the VM process. For details on the destination format, the best source is src/VBox/Runtime/common/log/log.cpp.

The destinations is one or more mnemonics, optionally prefixed by "no" to disable them. Some of them take values after a ":" or "=" separator. Multiple mnemonics can be separated by space or given as separate arguments on the command line.

List of available destination:

file[=file], nofile

Specifies a log file. It no filname is given, one will be generated based on the current UTC time and VM process name and placed in the current directory of the VM process. Note that this will currently not have any effect if the log file has already been opened.

dir=directory, nodir

Specifies the output directory for log files. Note that this will currently not have any effect if the log file has already been opened.

history=count, nohistory

A non-zero value enables log historization, with the value specifying how many old log files to keep.

histsize=bytes

The max size of a log file before it is historized. Default is infinite.

histtime=seconds

The max age (in seconds) of a log file before it is historized. Default is infinite.

ringbuffer, noringbuffer

Only log to the log buffer until an explicit flush (e.g. via an assertion) occurs. This is fast and saves diskspace.

stdout, nostdout

Write the log content to standard output.

stdout, nostdout

Write the log content to standard error.

debugger, nodebugger

Write the log content to the debugger, if supported by the host OS.

com, nocom

Writes logging to the COM port. This is only applicable for raw-mode and ring-0 logging.

user, nouser

Custom destination which has no meaning to VM processes..

This corresponds to the logdest command in the debugger.

7.42.2.7. debugvm logflags

VBoxManage debugvm { uuid|vmname } logflags [[--release] | [--debug]] [ flags ...]

Changes the flags on either debug (--debug) or release (--release) logger of the VM process. Please note that the modifications are applied onto the existing changes, they are not replacing them.

The flags are a list of flag mnemonics, optionally prefixed by a "no", "!", "~" or "-" to negate their meaning. The "+" prefix can be used to undo previous negation or use as a separator, though better use whitespace or separate arguments for that.

List of log flag mnemonics, with their counter form where applicable (asterisk indicates defaults):

enabled*, disabled

Enables or disables logging.

buffered, unbuffered*

Enabling buffering of log output before it hits the destinations.

writethrough(/writethru)

Whether to open the destination file with writethru buffering settings or not.

flush

Enables flushing of the output file (to disk) after each log statement.

lockcnts

Prefix each log line with lock counts for the current thread.

cpuid

Prefix each log line with the ID of the current CPU.

pid

Prefix each log line with the current process ID.

flagno

Prefix each log line with the numberic flags corresponding to the log statement.

flag

Prefix each log line with the flag mnemonics corresponding to the log statement.

groupno

Prefix each log line with the log group number for the log statement producing it.

group

Prefix each log line with the log group name for the log statement producing it.

tid

Prefix each log line with the current thread identifier.

thread

Prefix each log line with the current thread name.

time

Prefix each log line with the current UTC wall time.

timeprog

Prefix each log line with the current monotonic time since the start of the program.

msprog

Prefix each log line with the current monotonic timestamp value in milliseconds since the start of the program.

ts

Prefix each log line with the current monotonic timestamp value in nanoseconds.

tsc

Prefix each log line with the current CPU timestamp counter (TSC) value.

rel, abs*

Selects the whether ts and tsc prefixes should be displayed as relative to the previous log line or as absolute time.

hex*, dec

Selects the whether the ts and tsc prefixes should be formatted as hexadecimal or decimal.

custom

Custom log prefix, has by default no meaning for VM processes.

usecrlf, uself*

Output with DOS style (CRLF) or just UNIX style (LF) line endings.

overwrite*, append

Overwrite the destination file or append to it.

This corresponds to the logflags command in the debugger.

7.42.2.8. debugvm osdetect

VBoxManage debugvm { uuid|vmname } osdetect

Make the VMM's debugger facility (re)-detect the guest operating system (OS). This will first load all debugger plug-ins.

This corresponds to the detect command in the debugger.

7.42.2.9. debugvm osinfo

VBoxManage debugvm { uuid|vmname } osinfo

Displays information about the guest operating system (OS) previously detected by the VMM's debugger facility.

7.42.2.10. debugvm osdmesg

VBoxManage debugvm { uuid|vmname } osdmesg [--lines=lines]

Displays the guest OS kernel log, if detected and supported.

--lines=lines

Number of lines of the log to display, counting from the end. The default is infinite.

7.42.2.11. debugvm getregisters

VBoxManage debugvm { uuid|vmname } getregisters [--cpu=id] [ reg-set.reg-name ...]

Retrieves register values for guest CPUs and emulated devices.

reg-set.reg-name

One of more registers, each having one of the following forms:

  1. register-set.register-name.sub-field

  2. register-set.register-name

  3. cpu-register-name.sub-field

  4. cpu-register-name

  5. all

The all form will cause all registers to be shown (no sub-fields). The registers names are case-insensitive.

--cpu=id

Selects the CPU register set when specifying just a CPU register (3rd and 4th form). The default is 0.

7.42.2.12. debugvm setregisters

VBoxManage debugvm { uuid|vmname } setregisters [--cpu=id] [ reg-set.reg-name=value ...]

Changes register values for guest CPUs and emulated devices.

reg-set.reg-name=value

One of more register assignment, each having one of the following forms:

  1. register-set.register-name.sub-field=value

  2. register-set.register-name=value

  3. cpu-register-name.sub-field=value

  4. cpu-register-name=value

The value format should be in the same style as what getregisters displays, with the exception that both octal and decimal can be used instead of hexadecimal.

--cpu=id

Selects the CPU register set when specifying just a CPU register (3rd and 4th form). The default is 0.

7.42.2.13. debugvm show

VBoxManage debugvm { uuid|vmname } show [[--human-readable] | [--sh-export] | [--sh-eval] | [--cmd-set]] [ settings-item ...]

Shows logging settings for the VM.

--human-readable

Selects human readable output.

--sh-export

Selects output format as bourne shell style export commands.

--sh-eval

Selects output format as bourne shell style eval command input.

--cmd-set

Selects output format as DOS style SET commands.

settings-item

What to display. One or more of the following:

  • logdbg-settings - debug log settings.

  • logrel-settings - release log settings.

  • log-settings - alias for both debug and release log settings.

7.42.2.14. debugvm stack

VBoxManage debugvm { uuid|vmname } stack [--cpu=id]

Unwinds the guest CPU stacks to the best of our ability. It is recommended to first run the osdetect command, as this gives both symbols and perhaps unwind information.

--cpu=id

Selects a single guest CPU to display the stack for. The default is all CPUs.

7.42.2.15. debugvm statistics

VBoxManage debugvm { uuid|vmname } statistics [--reset] [--descriptions] [--pattern=pattern]

Displays or resets VMM statistics.

Retrieves register values for guest CPUs and emulated devices.

--pattern=pattern

DOS/NT-style wildcards patterns for selecting statistics. Multiple patterns can be specified by using the '|' (pipe) character as separator.

--reset

Select reset instead of display mode.