# perf-kvm

## NAME



           perf-kvm - Tool to trace/measure kvm guest os
    


## SYNOPSIS



           _perf kvm_ [--host] [--guest] [--guestmount=<path>
                   [--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]]
                   {top|record|report|diff|buildid-list} [<options>]
           _perf kvm_ [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
                   | --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat} [<options>]
           'perf kvm stat [record|report|live] [<options>]
    


## DESCRIPTION



           There are a couple of variants of perf kvm:
    
               'perf kvm [options] top <command>' to generates and displays
               a performance counter profile of guest os in realtime
               of an arbitrary workload.
    
               'perf kvm record <command>' to record the performance counter profile
               of an arbitrary workload and save it into a perf data file. We set the
               default behavior of perf kvm as --guest, so if neither --host nor --guest
               is input, the perf data file name is perf.data.guest. If --host is input,
               the perf data file name is perf.data.kvm. If you want to record data into
               perf.data.host, please input --host --no-guest. The behaviors are shown as
               following:
                 Default('')         ->  perf.data.guest
                 --host              ->  perf.data.kvm
                 --guest             ->  perf.data.guest
                 --host --guest      ->  perf.data.kvm
                 --host --no-guest   ->  perf.data.host
    
               'perf kvm report' to display the performance counter profile information
               recorded via perf kvm record.
    
               'perf kvm diff' to displays the performance difference amongst two perf.data
               files captured via perf record.
    
               'perf kvm buildid-list' to  display the buildids found in a perf data file,
               so that other tools can be used to fetch packages with matching symbol tables
               for use by perf report. As buildid is read from /sys/kernel/notes in os, then
               if you want to list the buildid for guest, please make sure your perf data file
               was captured with --guestmount in perf kvm record.
    
               'perf kvm stat <command>' to run a command and gather performance counter
               statistics.
               Especially, perf 'kvm stat record/report' generates a statistical analysis
               of KVM events. Currently, vmexit, mmio (x86 only) and ioport (x86 only)
               events are supported. 'perf kvm stat record <command>' records kvm events
               and the events between start and end <command>.
               And this command produces a file which contains tracing results of kvm
               events.
    
               'perf kvm stat report' reports statistical data which includes events
               handled sample, percent_sample, time, percent_time, max_t, min_t, mean_t.
    
               'perf kvm stat live' reports statistical data in a live mode (similar to
               record + report but with statistical data updated live at a given display
               rate).
    


## OPTIONS



           -i, --input=<path>
               Input file name, for the _report_ , _diff_ and _buildid-list_
               subcommands.
    
           -o, --output=<path>
               Output file name, for the _record_ subcommand. Doesn’t work with
               _report_ , just redirect the output to a file when using _report_.
    
           --host
               Collect host side performance profile.
    
           --guest
               Collect guest side performance profile.
    
           --guestmount=<path>
               Guest OS root file system mount directory. Users mount guest
               OS root directories under <path> by a specific filesystem
               access method, typically, sshfs. For example, start 2 guest
               OS, one’s pid is 8888 and the other’s is 9999:
    
                   $ mkdir ~/guestmount
                   $ cd ~/guestmount
                   $ sshfs -o allow_other,direct_io -p 5551 localhost:/ 8888/
                   $ sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/
                   $ perf kvm --host --guest --guestmount=~/guestmount top
    
           --guestkallsyms=<path>
               Guest OS /proc/kallsyms file copy. perf reads it to get guest
               kernel symbols. Users copy it out from guest OS.
    
           --guestmodules=<path>
               Guest OS /proc/modules file copy. perf reads it to get guest
               kernel module information. Users copy it out from guest OS.
    
           --guestvmlinux=<path>
               Guest OS kernel vmlinux.
    
           --guest-code
               Indicate that guest code can be found in the hypervisor
               process, which is a common case for KVM test programs.
    
           --stdio
               Use the stdio interface.
    
           -v, --verbose
               Be more verbose (show counter open errors, etc).
    


## STAT REPORT OPTIONS



           --vcpu=<value>
               analyze events which occur on this vcpu. (default: all vcpus)
    
           --event=<value>
               event to be analyzed. Possible values: vmexit, mmio (x86
               only), ioport (x86 only). (default: vmexit)
    
           -k, --key=<value>
               Sorting key. Possible values: sample (default, sort by samples
               number), percent_sample (sort by sample percentage), time
               (sort by average time), precent_time (sort by time
               percentage), max_t (sort by maximum time), min_t (sort by
               minimum time), mean_t (sort by mean time).
    
           -p, --pid=
               Analyze events only for given process ID(s) (comma separated
               list).
    


## STAT LIVE OPTIONS



           -d, --display
               Time in seconds between display updates
    
           -m, --mmap-pages=
               Number of mmap data pages (must be a power of two) or size
               specification in bytes with appended unit character - B/K/M/G.
               The size is rounded up to the nearest power-of-two page value.
    
           -a, --all-cpus
               System-wide collection from all CPUs.
    
           -p, --pid=
               Analyze events only for given process ID(s) (comma separated
               list).
    
           --vcpu=<value>
               analyze events which occur on this vcpu. (default: all vcpus)
    
           --event=<value>
               event to be analyzed. Possible values: vmexit, mmio (x86
               only), ioport (x86 only). (default: vmexit)
    
           -k, --key=<value>
               Sorting key. Possible values: sample (default, sort by samples
               number), time (sort by average time).
    
           --duration=<value>
               Show events other than HLT (x86 only) or Wait state (s390
               only) that take longer than duration usecs.
    
           --proc-map-timeout
               When processing pre-existing threads /proc/XXX/mmap, it may
               take a long time, because the file may be huge. A time out is
               needed in such cases. This option sets the time out limit. The
               default value is 500 ms.
    


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