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

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 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.type = PERF_TYPE_TRACEPOINT
        event_attr.size = ctypes.sizeof(event_attr)
        event_attr.config = int(open(id_path).read())
        event_attr.sample_period = 1
        event_attr.read_format = PERF_FORMAT_GROUP
        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.
        rlimit = len(cpus) * len(self._fields) + 50
        try:
            resource.setrlimit(resource.RLIMIT_NOFILE, (rlimit, rlimit))
        except ValueError:
            sys.exit("NOFILE rlimit could not be raised to {0}".format(rlimit))

        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)

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

    @fields.setter
    def fields(self, fields):
        self._fields = fields
        for group in self.group_leaders:
            for event in group.events:
                if event.name in fields:
                    event.reset()
                    event.enable()
                else:
                    event.disable()

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

class DebugfsProvider(object):
    def __init__(self):
        self._fields = 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.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.fields_filter = self.stats.fields_filter
        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.fields_filter:
            if self.drilldown:
                self.stats.fields_filter = None
            else:
                self.stats.fields_filter = r'^[^\(]*$'

    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_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
            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():
    optparser = optparse.OptionParser()
    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():
    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):
        sys.stderr.write("Please make {0} readable by the current user.\n"
                         .format(PATH_DEBUGFS_TRACING))
        sys.exit(1)

def main():
    check_access()
    options = get_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()