qapi/stats.json

   1 # -*- Mode: Python -*-
   2 # vim: filetype=python
   3 #
   4 # Copyright (c) 2022 Oracle and/or its affiliates.
   5 #
   6 # This work is licensed under the terms of the GNU GPL, version 2 or later.
   7 # See the COPYING file in the top-level directory.
   8 #
   9 # SPDX-License-Identifier: GPL-2.0-or-later
  10
  11 ##
  12 # = Statistics
  13 ##
  14
  15 ##
  16 # @StatsType:
  17 #
  18 # Enumeration of statistics types
  19 #
  20 # @cumulative: stat is cumulative; value can only increase.
  21 # @instant: stat is instantaneous; value can increase or decrease.
  22 # @peak: stat is the peak value; value can only increase.
  23 # @linear-histogram: stat is a linear histogram.
  24 # @log2-histogram: stat is a logarithmic histogram, with one bucket
  25 #                  for each power of two.
  26 #
  27 # Since: 7.1
  28 ##
  29 { 'enum' : 'StatsType',
  30   'data' : [ 'cumulative', 'instant', 'peak', 'linear-histogram',
  31              'log2-histogram' ] }
  32
  33 ##
  34 # @StatsUnit:
  35 #
  36 # Enumeration of unit of measurement for statistics
  37 #
  38 # @bytes: stat reported in bytes.
  39 # @seconds: stat reported in seconds.
  40 # @cycles: stat reported in clock cycles.
  41 # @boolean: stat is a boolean value.
  42 #
  43 # Since: 7.1
  44 ##
  45 { 'enum' : 'StatsUnit',
  46   'data' : [ 'bytes', 'seconds', 'cycles', 'boolean' ] }
  47
  48 ##
  49 # @StatsProvider:
  50 #
  51 # Enumeration of statistics providers.
  52 #
  53 # @kvm: since 7.1
  54 #
  55 # @cryptodev: since 8.0
  56 #
  57 # Since: 7.1
  58 ##
  59 { 'enum': 'StatsProvider',
  60   'data': [ 'kvm', 'cryptodev' ] }
  61
  62 ##
  63 # @StatsTarget:
  64 #
  65 # The kinds of objects on which one can request statistics.
  66 #
  67 # @vm: statistics that apply to the entire virtual machine or
  68 #      the entire QEMU process.
  69 #
  70 # @vcpu: statistics that apply to a single virtual CPU.
  71 #
  72 # @cryptodev: statistics that apply to a crypto device. since 8.0
  73 #
  74 # Since: 7.1
  75 ##
  76 { 'enum': 'StatsTarget',
  77   'data': [ 'vm', 'vcpu', 'cryptodev' ] }
  78
  79 ##
  80 # @StatsRequest:
  81 #
  82 # Indicates a set of statistics that should be returned by query-stats.
  83 #
  84 # @provider: provider for which to return statistics.
  85
  86 # @names: statistics to be returned (all if omitted).
  87 #
  88 # Since: 7.1
  89 ##
  90 { 'struct': 'StatsRequest',
  91   'data': { 'provider': 'StatsProvider',
  92             '*names': [ 'str' ] } }
  93
  94 ##
  95 # @StatsVCPUFilter:
  96 #
  97 # @vcpus: list of QOM paths for the desired vCPU objects.
  98 #
  99 # Since: 7.1
 100 ##
 101 { 'struct': 'StatsVCPUFilter',
 102   'data': { '*vcpus': [ 'str' ] } }
 103
 104 ##
 105 # @StatsFilter:
 106 #
 107 # The arguments to the query-stats command; specifies a target for which to
 108 # request statistics and optionally the required subset of information for
 109 # that target:
 110 # - which vCPUs to request statistics for
 111 # - which providers to request statistics from
 112 # - which named values to return within each provider
 113 #
 114 # Since: 7.1
 115 ##
 116 { 'union': 'StatsFilter',
 117   'base': {
 118       'target': 'StatsTarget',
 119       '*providers': [ 'StatsRequest' ] },
 120   'discriminator': 'target',
 121   'data': { 'vcpu': 'StatsVCPUFilter' } }
 122
 123 ##
 124 # @StatsValue:
 125 #
 126 # @scalar: single unsigned 64-bit integers.
 127 # @list: list of unsigned 64-bit integers (used for histograms).
 128 #
 129 # Since: 7.1
 130 ##
 131 { 'alternate': 'StatsValue',
 132   'data': { 'scalar': 'uint64',
 133             'boolean': 'bool',
 134             'list': [ 'uint64' ] } }
 135
 136 ##
 137 # @Stats:
 138 #
 139 # @name: name of stat.
 140 # @value: stat value.
 141 #
 142 # Since: 7.1
 143 ##
 144 { 'struct': 'Stats',
 145   'data': { 'name': 'str',
 146             'value' : 'StatsValue' } }
 147
 148 ##
 149 # @StatsResult:
 150 #
 151 # @provider: provider for this set of statistics.
 152 #
 153 # @qom-path: Path to the object for which the statistics are returned,
 154 #            if the object is exposed in the QOM tree
 155 #
 156 # @stats: list of statistics.
 157 #
 158 # Since: 7.1
 159 ##
 160 { 'struct': 'StatsResult',
 161   'data': { 'provider': 'StatsProvider',
 162             '*qom-path': 'str',
 163             'stats': [ 'Stats' ] } }
 164
 165 ##
 166 # @query-stats:
 167 #
 168 # Return runtime-collected statistics for objects such as the
 169 # VM or its vCPUs.
 170 #
 171 # The arguments are a StatsFilter and specify the provider and objects
 172 # to return statistics about.
 173 #
 174 # Returns: a list of StatsResult, one for each provider and object
 175 #          (e.g., for each vCPU).
 176 #
 177 # Since: 7.1
 178 ##
 179 { 'command': 'query-stats',
 180   'data': 'StatsFilter',
 181   'boxed': true,
 182   'returns': [ 'StatsResult' ] }
 183
 184 ##
 185 # @StatsSchemaValue:
 186 #
 187 # Schema for a single statistic.
 188 #
 189 # @name: name of the statistic; each element of the schema is uniquely
 190 #        identified by a target, a provider (both available in @StatsSchema)
 191 #        and the name.
 192 #
 193 # @type: kind of statistic.
 194 #
 195 # @unit: basic unit of measure for the statistic; if missing, the statistic
 196 #        is a simple number or counter.
 197 #
 198 # @base: base for the multiple of @unit in which the statistic is measured.
 199 #        Only present if @exponent is non-zero; @base and @exponent together
 200 #        form a SI prefix (e.g., _nano-_ for ``base=10`` and ``exponent=-9``)
 201 #        or IEC binary prefix (e.g. _kibi-_ for ``base=2`` and ``exponent=10``)
 202 #
 203 # @exponent: exponent for the multiple of @unit in which the statistic is
 204 #            expressed, or 0 for the basic unit
 205 #
 206 # @bucket-size: Present when @type is "linear-histogram", contains the width
 207 #               of each bucket of the histogram.
 208 #
 209 # Since: 7.1
 210 ##
 211 { 'struct': 'StatsSchemaValue',
 212   'data': { 'name': 'str',
 213             'type': 'StatsType',
 214             '*unit': 'StatsUnit',
 215             '*base': 'int8',
 216             'exponent': 'int16',
 217             '*bucket-size': 'uint32' } }
 218
 219 ##
 220 # @StatsSchema:
 221 #
 222 # Schema for all available statistics for a provider and target.
 223 #
 224 # @provider: provider for this set of statistics.
 225 #
 226 # @target: the kind of object that can be queried through the provider.
 227 #
 228 # @stats: list of statistics.
 229 #
 230 # Since: 7.1
 231 ##
 232 { 'struct': 'StatsSchema',
 233   'data': { 'provider': 'StatsProvider',
 234             'target': 'StatsTarget',
 235             'stats': [ 'StatsSchemaValue' ] } }
 236
 237 ##
 238 # @query-stats-schemas:
 239 #
 240 # Return the schema for all available runtime-collected statistics.
 241 #
 242 # Note: runtime-collected statistics and their names fall outside QEMU's usual
 243 #       deprecation policies.  QEMU will try to keep the set of available data
 244 #       stable, together with their names, but will not guarantee stability
 245 #       at all costs; the same is true of providers that source statistics
 246 #       externally, e.g. from Linux.  For example, if the same value is being
 247 #       tracked with different names on different architectures or by different
 248 #       providers, one of them might be renamed.  A statistic might go away if
 249 #       an algorithm is changed or some code is removed; changing a default
 250 #       might cause previously useful statistics to always report 0.  Such
 251 #       changes, however, are expected to be rare.
 252 #
 253 # Since: 7.1
 254 ##
 255 { 'command': 'query-stats-schemas',
 256   'data': { '*provider': 'StatsProvider' },
 257   'returns': [ 'StatsSchema' ] }