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 # Since: 7.1
  54 ##
  55 { 'enum': 'StatsProvider',
  56   'data': [ 'kvm' ] }
  57
  58 ##
  59 # @StatsTarget:
  60 #
  61 # The kinds of objects on which one can request statistics.
  62 #
  63 # @vm: statistics that apply to the entire virtual machine or
  64 #      the entire QEMU process.
  65 #
  66 # @vcpu: statistics that apply to a single virtual CPU.
  67 #
  68 # Since: 7.1
  69 ##
  70 { 'enum': 'StatsTarget',
  71   'data': [ 'vm', 'vcpu' ] }
  72
  73 ##
  74 # @StatsRequest:
  75 #
  76 # Indicates a set of statistics that should be returned by query-stats.
  77 #
  78 # @provider: provider for which to return statistics.
  79
  80 # @names: statistics to be returned (all if omitted).
  81 #
  82 # Since: 7.1
  83 ##
  84 { 'struct': 'StatsRequest',
  85   'data': { 'provider': 'StatsProvider',
  86             '*names': [ 'str' ] } }
  87
  88 ##
  89 # @StatsVCPUFilter:
  90 #
  91 # @vcpus: list of QOM paths for the desired vCPU objects.
  92 #
  93 # Since: 7.1
  94 ##
  95 { 'struct': 'StatsVCPUFilter',
  96   'data': { '*vcpus': [ 'str' ] } }
  97
  98 ##
  99 # @StatsFilter:
 100 #
 101 # The arguments to the query-stats command; specifies a target for which to
 102 # request statistics and optionally the required subset of information for
 103 # that target:
 104 # - which vCPUs to request statistics for
 105 # - which providers to request statistics from
 106 # - which named values to return within each provider
 107 #
 108 # Since: 7.1
 109 ##
 110 { 'union': 'StatsFilter',
 111   'base': {
 112       'target': 'StatsTarget',
 113       '*providers': [ 'StatsRequest' ] },
 114   'discriminator': 'target',
 115   'data': { 'vcpu': 'StatsVCPUFilter' } }
 116
 117 ##
 118 # @StatsValue:
 119 #
 120 # @scalar: single unsigned 64-bit integers.
 121 # @list: list of unsigned 64-bit integers (used for histograms).
 122 #
 123 # Since: 7.1
 124 ##
 125 { 'alternate': 'StatsValue',
 126   'data': { 'scalar': 'uint64',
 127             'boolean': 'bool',
 128             'list': [ 'uint64' ] } }
 129
 130 ##
 131 # @Stats:
 132 #
 133 # @name: name of stat.
 134 # @value: stat value.
 135 #
 136 # Since: 7.1
 137 ##
 138 { 'struct': 'Stats',
 139   'data': { 'name': 'str',
 140             'value' : 'StatsValue' } }
 141
 142 ##
 143 # @StatsResult:
 144 #
 145 # @provider: provider for this set of statistics.
 146 #
 147 # @qom-path: Path to the object for which the statistics are returned,
 148 #            if the object is exposed in the QOM tree
 149 #
 150 # @stats: list of statistics.
 151 #
 152 # Since: 7.1
 153 ##
 154 { 'struct': 'StatsResult',
 155   'data': { 'provider': 'StatsProvider',
 156             '*qom-path': 'str',
 157             'stats': [ 'Stats' ] } }
 158
 159 ##
 160 # @query-stats:
 161 #
 162 # Return runtime-collected statistics for objects such as the
 163 # VM or its vCPUs.
 164 #
 165 # The arguments are a StatsFilter and specify the provider and objects
 166 # to return statistics about.
 167 #
 168 # Returns: a list of StatsResult, one for each provider and object
 169 #          (e.g., for each vCPU).
 170 #
 171 # Since: 7.1
 172 ##
 173 { 'command': 'query-stats',
 174   'data': 'StatsFilter',
 175   'boxed': true,
 176   'returns': [ 'StatsResult' ] }
 177
 178 ##
 179 # @StatsSchemaValue:
 180 #
 181 # Schema for a single statistic.
 182 #
 183 # @name: name of the statistic; each element of the schema is uniquely
 184 #        identified by a target, a provider (both available in @StatsSchema)
 185 #        and the name.
 186 #
 187 # @type: kind of statistic.
 188 #
 189 # @unit: basic unit of measure for the statistic; if missing, the statistic
 190 #        is a simple number or counter.
 191 #
 192 # @base: base for the multiple of @unit in which the statistic is measured.
 193 #        Only present if @exponent is non-zero; @base and @exponent together
 194 #        form a SI prefix (e.g., _nano-_ for ``base=10`` and ``exponent=-9``)
 195 #        or IEC binary prefix (e.g. _kibi-_ for ``base=2`` and ``exponent=10``)
 196 #
 197 # @exponent: exponent for the multiple of @unit in which the statistic is
 198 #            expressed, or 0 for the basic unit
 199 #
 200 # @bucket-size: Present when @type is "linear-histogram", contains the width
 201 #               of each bucket of the histogram.
 202 #
 203 # Since: 7.1
 204 ##
 205 { 'struct': 'StatsSchemaValue',
 206   'data': { 'name': 'str',
 207             'type': 'StatsType',
 208             '*unit': 'StatsUnit',
 209             '*base': 'int8',
 210             'exponent': 'int16',
 211             '*bucket-size': 'uint32' } }
 212
 213 ##
 214 # @StatsSchema:
 215 #
 216 # Schema for all available statistics for a provider and target.
 217 #
 218 # @provider: provider for this set of statistics.
 219 #
 220 # @target: the kind of object that can be queried through the provider.
 221 #
 222 # @stats: list of statistics.
 223 #
 224 # Since: 7.1
 225 ##
 226 { 'struct': 'StatsSchema',
 227   'data': { 'provider': 'StatsProvider',
 228             'target': 'StatsTarget',
 229             'stats': [ 'StatsSchemaValue' ] } }
 230
 231 ##
 232 # @query-stats-schemas:
 233 #
 234 # Return the schema for all available runtime-collected statistics.
 235 #
 236 # Note: runtime-collected statistics and their names fall outside QEMU's usual
 237 #       deprecation policies.  QEMU will try to keep the set of available data
 238 #       stable, together with their names, but will not guarantee stability
 239 #       at all costs; the same is true of providers that source statistics
 240 #       externally, e.g. from Linux.  For example, if the same value is being
 241 #       tracked with different names on different architectures or by different
 242 #       providers, one of them might be renamed.  A statistic might go away if
 243 #       an algorithm is changed or some code is removed; changing a default
 244 #       might cause previously useful statistics to always report 0.  Such
 245 #       changes, however, are expected to be rare.
 246 #
 247 # Since: 7.1
 248 ##
 249 { 'command': 'query-stats-schemas',
 250   'data': { '*provider': 'StatsProvider' },
 251   'returns': [ 'StatsSchema' ] }