-options = optparse.OptionParser()
-options.add_option('-1', '--once', '--batch',
- action = 'store_true',
- default = False,
- dest = 'once',
- help = 'run in batch mode for one second',
- )
-options.add_option('-l', '--log',
- action = 'store_true',
- default = False,
- dest = 'log',
- help = 'run in logging mode (like vmstat)',
- )
-options.add_option('-t', '--tracepoints',
- action = 'store_true',
- default = False,
- dest = 'tracepoints',
- help = 'retrieve statistics from tracepoints',
- )
-options.add_option('-d', '--debugfs',
- action = 'store_true',
- default = False,
- dest = 'debugfs',
- help = 'retrieve statistics from debugfs',
- )
-options.add_option('-f', '--fields',
- action = 'store',
- default = None,
- dest = 'fields',
- help = 'fields to display (regex)',
- )
-(options, args) = options.parse_args(sys.argv)
-
-providers = []
-if options.tracepoints:
- providers.append(TracepointProvider())
-if options.debugfs:
- providers.append(DebugfsProvider())
-
-if len(providers) == 0:
- try:
- providers = [TracepointProvider()]
- except:
- providers = [DebugfsProvider()]
-
-stats = Stats(providers, fields = options.fields)
-
-if options.log:
- log(stats)
-elif not options.once:
- import curses.wrapper
- curses.wrapper(tui, stats)
-else:
- batch(stats)
+def get_options():
+ description_text = """
+This script displays various statistics about VMs running under KVM.
+The statistics are gathered from the KVM debugfs entries and / or the
+currently available perf traces.
+
+The monitoring takes additional cpu cycles and might affect the VM's
+performance.
+
+Requirements:
+- Access to:
+ /sys/kernel/debug/kvm
+ /sys/kernel/debug/trace/events/*
+ /proc/pid/task
+- /proc/sys/kernel/perf_event_paranoid < 1 if user has no
+ CAP_SYS_ADMIN and perf events are used.
+- CAP_SYS_RESOURCE if the hard limit is not high enough to allow
+ the large number of files that are possibly opened.
+"""
+
+ class PlainHelpFormatter(optparse.IndentedHelpFormatter):
+ def format_description(self, description):
+ if description:
+ return description + "\n"
+ else:
+ return ""
+
+ optparser = optparse.OptionParser(description=description_text,
+ formatter=PlainHelpFormatter())
+ optparser.add_option('-1', '--once', '--batch',
+ action='store_true',
+ default=False,
+ dest='once',
+ help='run in batch mode for one second',
+ )
+ optparser.add_option('-l', '--log',
+ action='store_true',
+ default=False,
+ dest='log',
+ help='run in logging mode (like vmstat)',
+ )
+ optparser.add_option('-t', '--tracepoints',
+ action='store_true',
+ default=False,
+ dest='tracepoints',
+ help='retrieve statistics from tracepoints',
+ )
+ optparser.add_option('-d', '--debugfs',
+ action='store_true',
+ default=False,
+ dest='debugfs',
+ help='retrieve statistics from debugfs',
+ )
+ optparser.add_option('-f', '--fields',
+ action='store',
+ default=None,
+ dest='fields',
+ help='fields to display (regex)',
+ )
+ (options, _) = optparser.parse_args(sys.argv)
+ return options
+
+def get_providers(options):
+ providers = []
+
+ if options.tracepoints:
+ providers.append(TracepointProvider())
+ if options.debugfs:
+ providers.append(DebugfsProvider())
+ if len(providers) == 0:
+ providers.append(TracepointProvider())
+
+ return providers
+
+def check_access(options):
+ if not os.path.exists('/sys/kernel/debug'):
+ sys.stderr.write('Please enable CONFIG_DEBUG_FS in your kernel.')
+ sys.exit(1)
+
+ if not os.path.exists(PATH_DEBUGFS_KVM):
+ sys.stderr.write("Please make sure, that debugfs is mounted and "
+ "readable by the current user:\n"
+ "('mount -t debugfs debugfs /sys/kernel/debug')\n"
+ "Also ensure, that the kvm modules are loaded.\n")
+ sys.exit(1)
+
+ if not os.path.exists(PATH_DEBUGFS_TRACING) and (options.tracepoints
+ or not options.debugfs):
+ sys.stderr.write("Please enable CONFIG_TRACING in your kernel "
+ "when using the option -t (default).\n"
+ "If it is enabled, make {0} readable by the "
+ "current user.\n"
+ .format(PATH_DEBUGFS_TRACING))
+ if options.tracepoints:
+ sys.exit(1)
+
+ sys.stderr.write("Falling back to debugfs statistics!\n")
+ options.debugfs = True
+ sleep(5)
+
+ return options
+
+def main():
+ options = get_options()
+ options = check_access(options)
+ providers = get_providers(options)
+ stats = Stats(providers, fields=options.fields)
+
+ if options.log:
+ log(stats)
+ elif not options.once:
+ with Tui(stats) as tui:
+ tui.show_stats()
+ else:
+ batch(stats)
+
+if __name__ == "__main__":
+ main()