From 1dbc0659acce676594060b331eb4d854d26eed0c Mon Sep 17 00:00:00 2001

From: David Hildenbrand <david@redhat.com>

Date: Tue, 17 Oct 2017 19:15:52 +0200

Subject: [PATCH 47/69] tools/kvm_stat: move functions to corresponding classes

RH-Author: David Hildenbrand <david@redhat.com>

Message-id: <20171017191605.2378-27-david@redhat.com>

Patchwork-id: 77334

O-Subject: [RHEL-7.5 qemu-kvm-rhev PATCH 26/39] tools/kvm_stat: move functions to corresponding classes

Bugzilla: 1497137

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

RH-Acked-by: Cornelia Huck <cohuck@redhat.com>

RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

Upstream-status: linux.git 099a2dfc674e3333bd4ff5e5b106ccd788aa46d7

commit 099a2dfc674e3333bd4ff5e5b106ccd788aa46d7

Author: Stefan Raspl <raspl@linux.vnet.ibm.com>

Date:   Wed Jun 7 21:08:33 2017 +0200

    tools/kvm_stat: move functions to corresponding classes

    Quite a few of the functions are used only in a single class. Moving

    functions accordingly to improve the overall structure.

    Furthermore, introduce a base class for the providers, which might also

    come handy for future extensions.

    Signed-off-by: Stefan Raspl <raspl@linux.vnet.ibm.com>

    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Signed-off-by: David Hildenbrand <david@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 scripts/kvm/kvm_stat | 327 ++++++++++++++++++++++++++-------------------------

 1 file changed, 165 insertions(+), 162 deletions(-)

diff --git a/scripts/kvm/kvm_stat b/scripts/kvm/kvm_stat

index b8522d2..f81ed20 100755

--- a/scripts/kvm/kvm_stat

+++ b/scripts/kvm/kvm_stat

@@ -295,121 +295,6 @@ class ArchS390(Arch):

 ARCH = Arch.get_arch()

-def is_field_wanted(fields_filter, field):

-    """Indicate whether field is valid according to fields_filter."""

-    if not fields_filter:

-        return True

-    return re.match(fields_filter, field) is not None

-

-

-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_pid_from_gname(gname):

-    """Fuzzy function to convert guest name to QEMU process pid.

-

-    Returns a list of potential pids, can be empty if no match found.

-    Throws an exception on processing errors.

-

-    """

-    pids = []

-    try:

-        child = subprocess.Popen(['ps', '-A', '--format', 'pid,args'],

-                                 stdout=subprocess.PIPE)

-    except:

-        raise Exception

-    for line in child.stdout:

-        line = line.lstrip().split(' ', 1)

-        # perform a sanity check before calling the more expensive

-        # function to possibly extract the guest name

-        if ' -name ' in line[1] and gname == get_gname_from_pid(line[0]):

-            pids.append(int(line[0]))

-    child.stdout.close()

-

-    return pids

-

-

-def get_gname_from_pid(pid):

-    """Returns the guest name for a QEMU process pid.

-

-    Extracts the guest name from the QEMU comma line by processing the '-name'

-    option. Will also handle names specified out of sequence.

-

-    """

-    name = ''

-    try:

-        line = open('/proc/{}/cmdline'.format(pid), 'rb').read().split('\0')

-        parms = line[line.index('-name') + 1].split(',')

-        while '' in parms:

-            # commas are escaped (i.e. ',,'), hence e.g. 'foo,bar' results in

-            # ['foo', '', 'bar'], which we revert here

-            idx = parms.index('')

-            parms[idx - 1] += ',' + parms[idx + 1]

-            del parms[idx:idx+2]

-        # the '-name' switch allows for two ways to specify the guest name,

-        # where the plain name overrides the name specified via 'guest='

-        for arg in parms:

-            if '=' not in arg:

-                name = arg

-                break

-            if arg[:6] == 'guest=':

-                name = arg[6:]

-    except (ValueError, IOError, IndexError):

-        pass

-

-    return name

-

-

-def get_online_cpus():

-    """Returns a list of cpu id integers."""

-    with open('/sys/devices/system/cpu/online') as cpu_list:

-        cpu_string = cpu_list.readline()

-        return parse_int_list(cpu_string)

-

-

-def get_filters():

-    """Returns a dict of trace events, their filter ids and

-    the values that can be filtered.

-

-    Trace events can be filtered for special values by setting a

-    filter string via an ioctl. The string normally has the format

-    identifier==value. For each filter a new event will be created, to

-    be able to distinguish the events.

-

-    """

-    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):

     """Struct that holds the necessary data to set up a trace event.

@@ -439,25 +324,6 @@ class perf_event_attr(ctypes.Structure):

         self.read_format = PERF_FORMAT_GROUP

-def perf_event_open(attr, pid, cpu, group_fd, flags):

-    """Wrapper for the sys_perf_evt_open() syscall.

-

-    Used to set up performance events, returns a file descriptor or -1

-    on error.

-

-    Attributes are:

-    - syscall number

-    - struct perf_event_attr *

-    - pid or -1 to monitor all pids

-    - cpu number or -1 to monitor all cpus

-    - The file descriptor of the group leader or -1 to create a group.

-    - 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

@@ -502,6 +368,8 @@ class Event(object):

     """Represents a performance event and manages its life cycle."""

     def __init__(self, name, group, trace_cpu, trace_pid, trace_point,

                  trace_filter, trace_set='kvm'):

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

+        self.syscall = self.libc.syscall

         self.name = name

         self.fd = None

         self.setup_event(group, trace_cpu, trace_pid, trace_point,

@@ -518,6 +386,25 @@ class Event(object):

         if self.fd:

             os.close(self.fd)

+    def perf_event_open(self, attr, pid, cpu, group_fd, flags):

+        """Wrapper for the sys_perf_evt_open() syscall.

+

+        Used to set up performance events, returns a file descriptor or -1

+        on error.

+

+        Attributes are:

+        - syscall number

+        - struct perf_event_attr *

+        - pid or -1 to monitor all pids

+        - cpu number or -1 to monitor all cpus

+        - The file descriptor of the group leader or -1 to create a group.

+        - flags

+

+        """

+        return self.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))

+

     def setup_event_attribute(self, trace_set, trace_point):

         """Returns an initialized ctype perf_event_attr struct."""

@@ -546,8 +433,8 @@ class Event(object):

         if group.events:

             group_leader = group.events[0].fd

-        fd = perf_event_open(event_attr, trace_pid,

-                             trace_cpu, group_leader, 0)

+        fd = self.perf_event_open(event_attr, trace_pid,

+                                  trace_cpu, group_leader, 0)

         if fd == -1:

             err = ctypes.get_errno()

             raise OSError(err, os.strerror(err),

@@ -582,7 +469,26 @@ class Event(object):

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

-class TracepointProvider(object):

+class Provider(object):

+    """Encapsulates functionalities used by all providers."""

+    @staticmethod

+    def is_field_wanted(fields_filter, field):

+        """Indicate whether field is valid according to fields_filter."""

+        if not fields_filter:

+            return True

+        return re.match(fields_filter, field) is not None

+

+    @staticmethod

+    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))

+

+

+class TracepointProvider(Provider):

     """Data provider for the stats class.

     Manages the events/groups from which it acquires its data.

@@ -590,10 +496,27 @@ class TracepointProvider(object):

     """

     def __init__(self, pid, fields_filter):

         self.group_leaders = []

-        self.filters = get_filters()

+        self.filters = self.get_filters()

         self.update_fields(fields_filter)

         self.pid = pid

+    @staticmethod

+    def get_filters():

+        """Returns a dict of trace events, their filter ids and

+        the values that can be filtered.

+

+        Trace events can be filtered for special values by setting a

+        filter string via an ioctl. The string normally has the format

+        identifier==value. For each filter a new event will be created, to

+        be able to distinguish the events.

+

+        """

+        filters = {}

+        filters['kvm_userspace_exit'] = ('reason', USERSPACE_EXIT_REASONS)

+        if ARCH.exit_reasons:

+            filters['kvm_exit'] = ('exit_reason', ARCH.exit_reasons)

+        return filters

+

     def get_available_fields(self):

         """Returns a list of available event's of format 'event name(filter

         name)'.

@@ -610,7 +533,7 @@ class TracepointProvider(object):

         """

         path = os.path.join(PATH_DEBUGFS_TRACING, 'events', 'kvm')

-        fields = walkdir(path)[1]

+        fields = self.walkdir(path)[1]

         extra = []

         for field in fields:

             if field in self.filters:

@@ -623,7 +546,30 @@ class TracepointProvider(object):

     def update_fields(self, fields_filter):

         """Refresh fields, applying fields_filter"""

         self._fields = [field for field in self.get_available_fields()

-                        if is_field_wanted(fields_filter, field)]

+                        if self.is_field_wanted(fields_filter, field)]

+

+    @staticmethod

+    def get_online_cpus():

+        """Returns a list of cpu id integers."""

+        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

+

+        with open('/sys/devices/system/cpu/online') as cpu_list:

+            cpu_string = cpu_list.readline()

+            return parse_int_list(cpu_string)

     def setup_traces(self):

         """Creates all event and group objects needed to be able to retrieve

@@ -633,9 +579,9 @@ class TracepointProvider(object):

             # Fetch list of all threads of the monitored pid, as qemu

             # starts a thread for each vcpu.

             path = os.path.join('/proc', str(self._pid), 'task')

-            groupids = walkdir(path)[1]

+            groupids = self.walkdir(path)[1]

         else:

-            groupids = get_online_cpus()

+            groupids = self.get_online_cpus()

         # The constant is needed as a buffer for python libs, std

         # streams and other files that the script opens.

@@ -732,7 +678,7 @@ class TracepointProvider(object):

                 event.reset()

-class DebugfsProvider(object):

+class DebugfsProvider(Provider):

     """Provides data from the files that KVM creates in the kvm debugfs

     folder."""

     def __init__(self, pid, fields_filter):

@@ -748,12 +694,12 @@ class DebugfsProvider(object):

         The fields are all available KVM debugfs files

         """

-        return walkdir(PATH_DEBUGFS_KVM)[2]

+        return self.walkdir(PATH_DEBUGFS_KVM)[2]

     def update_fields(self, fields_filter):

         """Refresh fields, applying fields_filter"""

         self._fields = [field for field in self.get_available_fields()

-                        if is_field_wanted(fields_filter, field)]

+                        if self.is_field_wanted(fields_filter, field)]

     @property

     def fields(self):

@@ -772,7 +718,7 @@ class DebugfsProvider(object):

     def pid(self, pid):

         self._pid = pid

         if pid != 0:

-            vms = walkdir(PATH_DEBUGFS_KVM)[1]

+            vms = self.walkdir(PATH_DEBUGFS_KVM)[1]

             if len(vms) == 0:

                 self.do_read = False

@@ -834,11 +780,23 @@ class Stats(object):

     """

     def __init__(self, options):

-        self.providers = get_providers(options)

+        self.providers = self.get_providers(options)

         self._pid_filter = options.pid

         self._fields_filter = options.fields

         self.values = {}

+    @staticmethod

+    def get_providers(options):

+        """Returns a list of data providers depending on the passed options."""

+        providers = []

+

+        if options.debugfs:

+            providers.append(DebugfsProvider(options.pid, options.fields))

+        if options.tracepoints or not providers:

+            providers.append(TracepointProvider(options.pid, options.fields))

+

+        return providers

+

     def update_provider_filters(self):

         """Propagates fields filters to providers."""

         # As we reset the counters when updating the fields we can

@@ -933,6 +891,63 @@ class Tui(object):

             curses.nocbreak()

             curses.endwin()

+    @staticmethod

+    def get_pid_from_gname(gname):

+        """Fuzzy function to convert guest name to QEMU process pid.

+

+        Returns a list of potential pids, can be empty if no match found.

+        Throws an exception on processing errors.

+

+        """

+        pids = []

+        try:

+            child = subprocess.Popen(['ps', '-A', '--format', 'pid,args'],

+                                     stdout=subprocess.PIPE)

+        except:

+            raise Exception

+        for line in child.stdout:

+            line = line.lstrip().split(' ', 1)

+            # perform a sanity check before calling the more expensive

+            # function to possibly extract the guest name

+            if (' -name ' in line[1] and

+                    gname == self.get_gname_from_pid(line[0])):

+                pids.append(int(line[0]))

+        child.stdout.close()

+

+        return pids

+

+    @staticmethod

+    def get_gname_from_pid(pid):

+        """Returns the guest name for a QEMU process pid.

+

+        Extracts the guest name from the QEMU comma line by processing the

+        '-name' option. Will also handle names specified out of sequence.

+

+        """

+        name = ''

+        try:

+            line = open('/proc/{}/cmdline'

+                        .format(pid), 'rb').read().split('\0')

+            parms = line[line.index('-name') + 1].split(',')

+            while '' in parms:

+                # commas are escaped (i.e. ',,'), hence e.g. 'foo,bar' results

+                # in # ['foo', '', 'bar'], which we revert here

+                idx = parms.index('')

+                parms[idx - 1] += ',' + parms[idx + 1]

+                del parms[idx:idx+2]

+            # the '-name' switch allows for two ways to specify the guest name,

+            # where the plain name overrides the name specified via 'guest='

+            for arg in parms:

+                if '=' not in arg:

+                    name = arg

+                    break

+                if arg[:6] == 'guest=':

+                    name = arg[6:]

+        except (ValueError, IOError, IndexError):

+            pass

+

+        return name

+

     def update_drilldown(self):

         """Sets or removes a filter that only allows fields without braces."""

         if not self.stats.fields_filter:

@@ -950,7 +965,7 @@ class Tui(object):

         if pid is None:

             pid = self.stats.pid_filter

         self.screen.erase()

-        gname = get_gname_from_pid(pid)

+        gname = self.get_gname_from_pid(pid)

         if gname:

             gname = ('({})'.format(gname[:MAX_GUEST_NAME_LEN] + '...'

                                    if len(gname) > MAX_GUEST_NAME_LEN

@@ -1096,7 +1111,7 @@ class Tui(object):

             else:

                 pids = []

                 try:

-                    pids = get_pid_from_gname(gname)

+                    pids = self.get_pid_from_gname(gname)

                 except:

                     msg = '"' + gname + '": Internal error while searching, ' \

                           'use pid filter instead'

@@ -1229,7 +1244,7 @@ Press any other key to refresh statistics immediately.

     def cb_guest_to_pid(option, opt, val, parser):

         try:

-            pids = get_pid_from_gname(val)

+            pids = Tui.get_pid_from_gname(val)

         except:

             raise optparse.OptionValueError('Error while searching for guest '

                                             '"{}", use "-p" to specify a pid '

@@ -1294,18 +1309,6 @@ Press any other key to refresh statistics immediately.

     return options

-def get_providers(options):

-    """Returns a list of data providers depending on the passed options."""

-    providers = []

-

-    if options.debugfs:

-        providers.append(DebugfsProvider(options.pid, options.fields))

-    if options.tracepoints or not providers:

-        providers.append(TracepointProvider(options.pid, options.fields))

-

-    return providers

-

-

 def check_access(options):

     """Exits if the current user can't access all needed directories."""

     if not os.path.exists('/sys/kernel/debug'):

-- 

1.8.3.1