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KVM_STAT(1)   KVM_STAT(1)

NAME

kvm_stat - Report KVM kernel module event counters

SYNOPSIS

kvm_stat [OPTION]...

DESCRIPTION

kvm_stat prints counts of KVM kernel module trace events. These events signify state transitions such as guest mode entry and exit.

This tool is useful for observing guest behavior from the host perspective. Often conclusions about performance or buggy behavior can be drawn from the output. While running in regular mode, use any of the keys listed in section Interactive Commands below. Use batch and logging modes for scripting purposes.

The set of KVM kernel module trace events may be specific to the kernel version or architecture. It is best to check the KVM kernel module source code for the meaning of events.

INTERACTIVE COMMANDS

b toggle events by guests (debugfs only, honors filters)
c clear filter
f filter by regular expression
Note: Child events pull in their parents, and parents' stats summarize all child events, not just the filtered ones
g filter by guest name/PID
h display interactive commands reference
o toggle sorting order (Total vs CurAvg/s)
p filter by guest name/PID
q quit
r reset stats
s set delay between refreshs
x toggle reporting of stats for child trace events
Note: The stats for the parents summarize the respective child trace events

Press any other key to refresh statistics immediately.

OPTIONS

-1, --once, --batch

run in batch mode for one second

-c, --csv

log in csv format. Requires option -l/--log or -L/--log-to-file. When used with option -L/--log-to-file, the header is only ever written to start of file to preserve the format.

-d, --debugfs

retrieve statistics from debugfs

-f<fields>, --fields=<fields>

fields to display (regex), "-f help" for a list of available events

-g<guest>, --guest=<guest_name>

limit statistics to one virtual machine (guest name)

-h, --help

show help message

-i, --debugfs-include-past

include all available data on past events for debugfs

-l, --log

run in logging mode (like vmstat)

-L<file>, --log-to-file=<file>

like -l/--log, but logging to a file. Appends to existing files.

-p<pid>, --pid=<pid>

limit statistics to one virtual machine (pid)

-s, --set-delay

set delay between refreshs (value range: 0.1-25.5 secs)

-t, --tracepoints

retrieve statistics from tracepoints

-z, --skip-zero-records

omit records with all zeros in logging mode

SIGNALS

when kvm_stat is running in logging mode (either with -l or with -L), it handles the following signals:

SIGHUP - closes and reopens the log file (-L only), then continues.

SIGINT - closes the log file and terminates. SIGTERM - closes the log file and terminates.

SEE ALSO

perf(1), trace-cmd(1)

AUTHOR

Stefan Hajnoczi <stefanha@redhat.com>

10/29/2024