kvm_stat

#!/usr/bin/python
#
# top-like utility for displaying kvm statistics
#
# Copyright 2006-2008 Qumranet Technologies
# Copyright 2008-2011 Red Hat, Inc.
#
# Authors:
#  Avi Kivity <avi@redhat.com>
#
# This work is licensed under the terms of the GNU GPL, version 2.  See
# the COPYING file in the top-level directory.

import curses
import sys
import os
import time
import optparse
import ctypes
import fcntl
import resource
import struct
import re
from collections import defaultdict
from time import sleep

VMX_EXIT_REASONS = {
    'EXCEPTION_NMI':        0,
    'EXTERNAL_INTERRUPT':   1,
    'TRIPLE_FAULT':         2,
    'PENDING_INTERRUPT':    7,
    'NMI_WINDOW':           8,
    'TASK_SWITCH':          9,
    'CPUID':                10,
    'HLT':                  12,
    'INVLPG':               14,
    'RDPMC':                15,
    'RDTSC':                16,
    'VMCALL':               18,
    'VMCLEAR':              19,
    'VMLAUNCH':             20,
    'VMPTRLD':              21,
    'VMPTRST':              22,
    'VMREAD':               23,
    'VMRESUME':             24,
    'VMWRITE':              25,
    'VMOFF':                26,
    'VMON':                 27,
    'CR_ACCESS':            28,
    'DR_ACCESS':            29,
    'IO_INSTRUCTION':       30,
    'MSR_READ':             31,
    'MSR_WRITE':            32,
    'INVALID_STATE':        33,
    'MWAIT_INSTRUCTION':    36,
    'MONITOR_INSTRUCTION':  39,
    'PAUSE_INSTRUCTION':    40,
    'MCE_DURING_VMENTRY':   41,
    'TPR_BELOW_THRESHOLD':  43,
    'APIC_ACCESS':          44,
    'EPT_VIOLATION':        48,
    'EPT_MISCONFIG':        49,
    'WBINVD':               54,
    'XSETBV':               55,
    'APIC_WRITE':           56,
    'INVPCID':              58,
}

SVM_EXIT_REASONS = {
    'READ_CR0':       0x000,
    'READ_CR3':       0x003,
    'READ_CR4':       0x004,
    'READ_CR8':       0x008,
    'WRITE_CR0':      0x010,
    'WRITE_CR3':      0x013,
    'WRITE_CR4':      0x014,
    'WRITE_CR8':      0x018,
    'READ_DR0':       0x020,
    'READ_DR1':       0x021,
    'READ_DR2':       0x022,
    'READ_DR3':       0x023,
    'READ_DR4':       0x024,
    'READ_DR5':       0x025,
    'READ_DR6':       0x026,
    'READ_DR7':       0x027,
    'WRITE_DR0':      0x030,
    'WRITE_DR1':      0x031,
    'WRITE_DR2':      0x032,
    'WRITE_DR3':      0x033,
    'WRITE_DR4':      0x034,
    'WRITE_DR5':      0x035,
    'WRITE_DR6':      0x036,
    'WRITE_DR7':      0x037,
    'EXCP_BASE':      0x040,
    'INTR':           0x060,
    'NMI':            0x061,
    'SMI':            0x062,
    'INIT':           0x063,
    'VINTR':          0x064,
    'CR0_SEL_WRITE':  0x065,
    'IDTR_READ':      0x066,
    'GDTR_READ':      0x067,
    'LDTR_READ':      0x068,
    'TR_READ':        0x069,
    'IDTR_WRITE':     0x06a,
    'GDTR_WRITE':     0x06b,
    'LDTR_WRITE':     0x06c,
    'TR_WRITE':       0x06d,
    'RDTSC':          0x06e,
    'RDPMC':          0x06f,
    'PUSHF':          0x070,
    'POPF':           0x071,
    'CPUID':          0x072,
    'RSM':            0x073,
    'IRET':           0x074,
    'SWINT':          0x075,
    'INVD':           0x076,
    'PAUSE':          0x077,
    'HLT':            0x078,
    'INVLPG':         0x079,
    'INVLPGA':        0x07a,
    'IOIO':           0x07b,
    'MSR':            0x07c,
    'TASK_SWITCH':    0x07d,
    'FERR_FREEZE':    0x07e,
    'SHUTDOWN':       0x07f,
    'VMRUN':          0x080,
    'VMMCALL':        0x081,
    'VMLOAD':         0x082,
    'VMSAVE':         0x083,
    'STGI':           0x084,
    'CLGI':           0x085,
    'SKINIT':         0x086,
    'RDTSCP':         0x087,
    'ICEBP':          0x088,
    'WBINVD':         0x089,
    'MONITOR':        0x08a,
    'MWAIT':          0x08b,
    'MWAIT_COND':     0x08c,
    'XSETBV':         0x08d,
    'NPF':            0x400,
}

# EC definition of HSR (from arch/arm64/include/asm/kvm_arm.h)
AARCH64_EXIT_REASONS = {
    'UNKNOWN':      0x00,
    'WFI':          0x01,
    'CP15_32':      0x03,
    'CP15_64':      0x04,
    'CP14_MR':      0x05,
    'CP14_LS':      0x06,
    'FP_ASIMD':     0x07,
    'CP10_ID':      0x08,
    'CP14_64':      0x0C,
    'ILL_ISS':      0x0E,
    'SVC32':        0x11,
    'HVC32':        0x12,
    'SMC32':        0x13,
    'SVC64':        0x15,
    'HVC64':        0x16,
    'SMC64':        0x17,
    'SYS64':        0x18,
    'IABT':         0x20,
    'IABT_HYP':     0x21,
    'PC_ALIGN':     0x22,
    'DABT':         0x24,
    'DABT_HYP':     0x25,
    'SP_ALIGN':     0x26,
    'FP_EXC32':     0x28,
    'FP_EXC64':     0x2C,
    'SERROR':       0x2F,
    'BREAKPT':      0x30,
    'BREAKPT_HYP':  0x31,
    'SOFTSTP':      0x32,
    'SOFTSTP_HYP':  0x33,
    'WATCHPT':      0x34,
    'WATCHPT_HYP':  0x35,
    'BKPT32':       0x38,
    'VECTOR32':     0x3A,
    'BRK64':        0x3C,
}

# From include/uapi/linux/kvm.h, KVM_EXIT_xxx
USERSPACE_EXIT_REASONS = {
    'UNKNOWN':          0,
    'EXCEPTION':        1,
    'IO':               2,
    'HYPERCALL':        3,
    'DEBUG':            4,
    'HLT':              5,
    'MMIO':             6,
    'IRQ_WINDOW_OPEN':  7,
    'SHUTDOWN':         8,
    'FAIL_ENTRY':       9,
    'INTR':             10,
    'SET_TPR':          11,
    'TPR_ACCESS':       12,
    'S390_SIEIC':       13,
    'S390_RESET':       14,
    'DCR':              15,
    'NMI':              16,
    'INTERNAL_ERROR':   17,
    'OSI':              18,
    'PAPR_HCALL':       19,
    'S390_UCONTROL':    20,
    'WATCHDOG':         21,
    'S390_TSCH':        22,
    'EPR':              23,
    'SYSTEM_EVENT':     24,
}

IOCTL_NUMBERS = {
    'SET_FILTER':  0x40082406,
    'ENABLE':      0x00002400,
    'DISABLE':     0x00002401,
    'RESET':       0x00002403,
}

class Arch(object):
    """Class that encapsulates global architecture specific data like
    syscall and ioctl numbers.

    """
    @staticmethod
    def get_arch():
        machine = os.uname()[4]

        if machine.startswith('ppc'):
            return ArchPPC()
        elif machine.startswith('aarch64'):
            return ArchA64()
        elif machine.startswith('s390'):
            return ArchS390()
        else:
            # X86_64
            for line in open('/proc/cpuinfo'):
                if not line.startswith('flags'):
                    continue

                flags = line.split()
                if 'vmx' in flags:
                    return ArchX86(VMX_EXIT_REASONS)
                if 'svm' in flags:
                    return ArchX86(SVM_EXIT_REASONS)
                return

class ArchX86(Arch):
    def __init__(self, exit_reasons):
        self.sc_perf_evt_open = 298
        self.ioctl_numbers = IOCTL_NUMBERS
        self.exit_reasons = exit_reasons

class ArchPPC(Arch):
    def __init__(self):
        self.sc_perf_evt_open = 319
        self.ioctl_numbers = IOCTL_NUMBERS
        self.ioctl_numbers['ENABLE'] = 0x20002400
        self.ioctl_numbers['DISABLE'] = 0x20002401

        # PPC comes in 32 and 64 bit and some generated ioctl
        # numbers depend on the wordsize.
        char_ptr_size = ctypes.sizeof(ctypes.c_char_p)
        self.ioctl_numbers['SET_FILTER'] = 0x80002406 | char_ptr_size << 16

class ArchA64(Arch):
    def __init__(self):
        self.sc_perf_evt_open = 241
        self.ioctl_numbers = IOCTL_NUMBERS
        self.exit_reasons = AARCH64_EXIT_REASONS

class ArchS390(Arch):
    def __init__(self):
        self.sc_perf_evt_open = 331
        self.ioctl_numbers = IOCTL_NUMBERS
        self.exit_reasons = None

ARCH = Arch.get_arch()


def walkdir(path):
    """Returns os.walk() data for specified directory.

    As it is only a wrapper it returns the same 3-tuple of (dirpath,
    dirnames, filenames).
    """
    return next(os.walk(path))


def parse_int_list(list_string):
    """Returns an int list from a string of comma separated integers and
    integer ranges."""
    integers = []
    members = list_string.split(',')

    for member in members:
        if '-' not in member:
            integers.append(int(member))
        else:
            int_range = member.split('-')
            integers.extend(range(int(int_range[0]),
                                  int(int_range[1]) + 1))

    return integers


def get_online_cpus():
    with open('/sys/devices/system/cpu/online') as cpu_list:
        cpu_string = cpu_list.readline()
        return parse_int_list(cpu_string)


def get_filters():
    filters = {}
    filters['kvm_userspace_exit'] = ('reason', USERSPACE_EXIT_REASONS)
    if ARCH.exit_reasons:
        filters['kvm_exit'] = ('exit_reason', ARCH.exit_reasons)
    return filters

libc = ctypes.CDLL('libc.so.6', use_errno=True)
syscall = libc.syscall

class perf_event_attr(ctypes.Structure):
    _fields_ = [('type', ctypes.c_uint32),
                ('size', ctypes.c_uint32),
                ('config', ctypes.c_uint64),
                ('sample_freq', ctypes.c_uint64),
                ('sample_type', ctypes.c_uint64),
                ('read_format', ctypes.c_uint64),
                ('flags', ctypes.c_uint64),
                ('wakeup_events', ctypes.c_uint32),
                ('bp_type', ctypes.c_uint32),
                ('bp_addr', ctypes.c_uint64),
                ('bp_len', ctypes.c_uint64),
                ]

    def __init__(self):
        super(self.__class__, self).__init__()
        self.type = PERF_TYPE_TRACEPOINT
        self.size = ctypes.sizeof(self)
        self.read_format = PERF_FORMAT_GROUP

def perf_event_open(attr, pid, cpu, group_fd, flags):
    return syscall(ARCH.sc_perf_evt_open, ctypes.pointer(attr),
                   ctypes.c_int(pid), ctypes.c_int(cpu),
                   ctypes.c_int(group_fd), ctypes.c_long(flags))

PERF_TYPE_TRACEPOINT = 2
PERF_FORMAT_GROUP = 1 << 3

PATH_DEBUGFS_TRACING = '/sys/kernel/debug/tracing'
PATH_DEBUGFS_KVM = '/sys/kernel/debug/kvm'

class Group(object):
    def __init__(self):
        self.events = []

    def add_event(self, event):
        self.events.append(event)

    def read(self):
        length = 8 * (1 + len(self.events))
        read_format = 'xxxxxxxx' + 'Q' * len(self.events)
        return dict(zip([event.name for event in self.events],
                        struct.unpack(read_format,
                                      os.read(self.events[0].fd, length))))

class Event(object):
    def __init__(self, name, group, trace_cpu, trace_point, trace_filter,
                 trace_set='kvm'):
        self.name = name
        self.fd = None
        self.setup_event(group, trace_cpu, trace_point, trace_filter,
                         trace_set)

    def setup_event_attribute(self, trace_set, trace_point):
        id_path = os.path.join(PATH_DEBUGFS_TRACING, 'events', trace_set,
                               trace_point, 'id')

        event_attr = perf_event_attr()
        event_attr.config = int(open(id_path).read())
        return event_attr

    def setup_event(self, group, trace_cpu, trace_point, trace_filter,
                    trace_set):
        event_attr = self.setup_event_attribute(trace_set, trace_point)

        group_leader = -1
        if group.events:
            group_leader = group.events[0].fd

        fd = perf_event_open(event_attr, -1, trace_cpu,
                             group_leader, 0)
        if fd == -1:
            err = ctypes.get_errno()
            raise OSError(err, os.strerror(err),
                          'while calling sys_perf_event_open().')

        if trace_filter:
            fcntl.ioctl(fd, ARCH.ioctl_numbers['SET_FILTER'],
                        trace_filter)

        self.fd = fd

    def enable(self):
        fcntl.ioctl(self.fd, ARCH.ioctl_numbers['ENABLE'], 0)

    def disable(self):
        fcntl.ioctl(self.fd, ARCH.ioctl_numbers['DISABLE'], 0)

    def reset(self):
        fcntl.ioctl(self.fd, ARCH.ioctl_numbers['RESET'], 0)

class TracepointProvider(object):
    def __init__(self):
        self.group_leaders = []
        self.filters = get_filters()
        self._fields = self.get_available_fields()
        self.setup_traces()
        self.fields = self._fields

    def get_available_fields(self):
        path = os.path.join(PATH_DEBUGFS_TRACING, 'events', 'kvm')
        fields = walkdir(path)[1]
        extra = []
        for field in fields:
            if field in self.filters:
                filter_name_, filter_dicts = self.filters[field]
                for name in filter_dicts:
                    extra.append(field + '(' + name + ')')
        fields += extra
        return fields

    def setup_traces(self):
        cpus = get_online_cpus()

        # The constant is needed as a buffer for python libs, std
        # streams and other files that the script opens.
        newlim = len(cpus) * len(self._fields) + 50
        try:
            softlim_, hardlim = resource.getrlimit(resource.RLIMIT_NOFILE)

            if hardlim < newlim:
                # Now we need CAP_SYS_RESOURCE, to increase the hard limit.
                resource.setrlimit(resource.RLIMIT_NOFILE, (newlim, newlim))
            else:
                # Raising the soft limit is sufficient.
                resource.setrlimit(resource.RLIMIT_NOFILE, (newlim, hardlim))

        except ValueError:
            sys.exit("NOFILE rlimit could not be raised to {0}".format(newlim))

        for cpu in cpus:
            group = Group()
            for name in self._fields:
                tracepoint = name
                tracefilter = None
                match = re.match(r'(.*)\((.*)\)', name)
                if match:
                    tracepoint, sub = match.groups()
                    tracefilter = ('%s==%d\0' %
                                   (self.filters[tracepoint][0],
                                    self.filters[tracepoint][1][sub]))

                group.add_event(Event(name=name,
                                      group=group,
                                      trace_cpu=cpu,
                                      trace_point=tracepoint,
                                      trace_filter=tracefilter))
            self.group_leaders.append(group)

    def available_fields(self):
        return self.get_available_fields()

    @property
    def fields(self):
        return self._fields

    @fields.setter
    def fields(self, fields):
        self._fields = fields
        for group in self.group_leaders:
            for index, event in enumerate(group.events):
                if event.name in fields:
                    event.reset()
                    event.enable()
                else:
                    # Do not disable the group leader.
                    # It would disable all of its events.
                    if index != 0:
                        event.disable()

    def read(self):
        ret = defaultdict(int)
        for group in self.group_leaders:
            for name, val in group.read().iteritems():
                if name in self._fields:
                    ret[name] += val
        return ret

class DebugfsProvider(object):
    def __init__(self):
        self._fields = self.get_available_fields()

    def get_available_fields(self):
        return walkdir(PATH_DEBUGFS_KVM)[2]

    @property
    def fields(self):
        return self._fields

    @fields.setter
    def fields(self, fields):
        self._fields = fields

    def read(self):
        def val(key):
            return int(file(PATH_DEBUGFS_KVM + '/' + key).read())
        return dict([(key, val(key)) for key in self._fields])

class Stats(object):
    def __init__(self, providers, fields=None):
        self.providers = providers
        self._fields_filter = fields
        self.values = {}
        self.update_provider_filters()

    def update_provider_filters(self):
        def wanted(key):
            if not self._fields_filter:
                return True
            return re.match(self._fields_filter, key) is not None

        # As we reset the counters when updating the fields we can
        # also clear the cache of old values.
        self.values = {}
        for provider in self.providers:
            provider_fields = [key for key in provider.get_available_fields()
                               if wanted(key)]
            provider.fields = provider_fields

    @property
    def fields_filter(self):
        return self._fields_filter

    @fields_filter.setter
    def fields_filter(self, fields_filter):
        self._fields_filter = fields_filter
        self.update_provider_filters()

    def get(self):
        for provider in self.providers:
            new = provider.read()
            for key in provider.fields:
                oldval = self.values.get(key, (0, 0))
                newval = new.get(key, 0)
                newdelta = None
                if oldval is not None:
                    newdelta = newval - oldval[0]
                self.values[key] = (newval, newdelta)
        return self.values

LABEL_WIDTH = 40
NUMBER_WIDTH = 10

class Tui(object):
    def __init__(self, stats):
        self.stats = stats
        self.screen = None
        self.drilldown = False
        self.update_drilldown()

    def __enter__(self):
        """Initialises curses for later use.  Based on curses.wrapper
           implementation from the Python standard library."""
        self.screen = curses.initscr()
        curses.noecho()
        curses.cbreak()

        # The try/catch works around a minor bit of
        # over-conscientiousness in the curses module, the error
        # return from C start_color() is ignorable.
        try:
            curses.start_color()
        except:
            pass

        curses.use_default_colors()
        return self

    def __exit__(self, *exception):
        """Resets the terminal to its normal state.  Based on curses.wrappre
           implementation from the Python standard library."""
        if self.screen:
            self.screen.keypad(0)
            curses.echo()
            curses.nocbreak()
            curses.endwin()

    def update_drilldown(self):
        if not self.stats.fields_filter:
            self.stats.fields_filter = r'^[^\(]*$'

        elif self.stats.fields_filter == r'^[^\(]*$':
            self.stats.fields_filter = None

    def refresh(self, sleeptime):
        self.screen.erase()
        self.screen.addstr(0, 0, 'kvm statistics - summary', curses.A_BOLD)
        self.screen.addstr(2, 1, 'Event')
        self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH -
                           len('Total'), 'Total')
        self.screen.addstr(2, 1 + LABEL_WIDTH + NUMBER_WIDTH + 8 -
                           len('Current'), 'Current')
        row = 3
        stats = self.stats.get()
        def sortkey(x):
            if stats[x][1]:
                return (-stats[x][1], -stats[x][0])
            else:
                return (0, -stats[x][0])
        for key in sorted(stats.keys(), key=sortkey):

            if row >= self.screen.getmaxyx()[0]:
                break
            values = stats[key]
            if not values[0] and not values[1]:
                break
            col = 1
            self.screen.addstr(row, col, key)
            col += LABEL_WIDTH
            self.screen.addstr(row, col, '%10d' % (values[0],))
            col += NUMBER_WIDTH
            if values[1] is not None:
                self.screen.addstr(row, col, '%8d' % (values[1] / sleeptime,))
            row += 1
        self.screen.refresh()

    def show_filter_selection(self):
        while True:
            self.screen.erase()
            self.screen.addstr(0, 0,
                               "Show statistics for events matching a regex.",
                               curses.A_BOLD)
            self.screen.addstr(2, 0,
                               "Current regex: {0}"
                               .format(self.stats.fields_filter))
            self.screen.addstr(3, 0, "New regex: ")
            curses.echo()
            regex = self.screen.getstr()
            curses.noecho()
            if len(regex) == 0:
                return
            try:
                re.compile(regex)
                self.stats.fields_filter = regex
                return
            except re.error:
                continue

    def show_stats(self):
        sleeptime = 0.25
        while True:
            self.refresh(sleeptime)
            curses.halfdelay(int(sleeptime * 10))
            sleeptime = 3
            try:
                char = self.screen.getkey()
                if char == 'x':
                    self.drilldown = not self.drilldown
                    self.update_drilldown()
                if char == 'q':
                    break
                if char == 'f':
                    self.show_filter_selection()
            except KeyboardInterrupt:
                break
            except curses.error:
                continue

def batch(stats):
    s = stats.get()
    time.sleep(1)
    s = stats.get()
    for key in sorted(s.keys()):
        values = s[key]
        print '%-42s%10d%10d' % (key, values[0], values[1])

def log(stats):
    keys = sorted(stats.get().iterkeys())
    def banner():
        for k in keys:
            print '%s' % k,
        print
    def statline():
        s = stats.get()
        for k in keys:
            print ' %9d' % s[k][1],
        print
    line = 0
    banner_repeat = 20
    while True:
        time.sleep(1)
        if line % banner_repeat == 0:
            banner()
        statline()
        line += 1

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()