trace/control.h

   1 /*
   2  * Interface for configuring and controlling the state of tracing events.
   3  *
   4  * Copyright (C) 2011-2016 Lluís Vilanova <vilanova@ac.upc.edu>
   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
  10 #ifndef TRACE__CONTROL_H
  11 #define TRACE__CONTROL_H
  12
  13 #include "event-internal.h"
  14
  15 typedef struct TraceEventIter {
  16     size_t event;
  17     size_t group;
  18     const char *pattern;
  19 } TraceEventIter;
  20
  21
  22 /**
  23  * trace_event_iter_init:
  24  * @iter: the event iterator struct
  25  * @pattern: optional pattern to filter events on name
  26  *
  27  * Initialize the event iterator struct @iter,
  28  * optionally using @pattern to filter out events
  29  * with non-matching names.
  30  */
  31 void trace_event_iter_init(TraceEventIter *iter, const char *pattern);
  32
  33 /**
  34  * trace_event_iter_next:
  35  * @iter: the event iterator struct
  36  *
  37  * Get the next event, if any. When this returns NULL,
  38  * the iterator should no longer be used.
  39  *
  40  * Returns: the next event, or NULL if no more events exist
  41  */
  42 TraceEvent *trace_event_iter_next(TraceEventIter *iter);
  43
  44
  45 /**
  46  * trace_event_name:
  47  * @id: Event name.
  48  *
  49  * Search an event by its name.
  50  *
  51  * Returns: pointer to #TraceEvent or NULL if not found.
  52  */
  53 TraceEvent *trace_event_name(const char *name);
  54
  55 /**
  56  * trace_event_is_pattern:
  57  *
  58  * Whether the given string is an event name pattern.
  59  */
  60 static bool trace_event_is_pattern(const char *str);
  61
  62
  63 /**
  64  * trace_event_get_id:
  65  *
  66  * Get the identifier of an event.
  67  */
  68 static uint32_t trace_event_get_id(TraceEvent *ev);
  69
  70 /**
  71  * trace_event_get_vcpu_id:
  72  *
  73  * Get the per-vCPU identifier of an event.
  74  *
  75  * Special value #TRACE_VCPU_EVENT_NONE means the event is not vCPU-specific
  76  * (does not have the "vcpu" property).
  77  */
  78 static uint32_t trace_event_get_vcpu_id(TraceEvent *ev);
  79
  80 /**
  81  * trace_event_is_vcpu:
  82  *
  83  * Whether this is a per-vCPU event.
  84  */
  85 static bool trace_event_is_vcpu(TraceEvent *ev);
  86
  87 /**
  88  * trace_event_get_name:
  89  *
  90  * Get the name of an event.
  91  */
  92 static const char * trace_event_get_name(TraceEvent *ev);
  93
  94 /**
  95  * trace_event_get_state:
  96  * @id: Event identifier name.
  97  *
  98  * Get the tracing state of an event, both static and the QEMU dynamic state.
  99  *
 100  * If the event has the disabled property, the check will have no performance
 101  * impact.
 102  */
 103 #define trace_event_get_state(id)                       \
 104     ((id ##_ENABLED) && trace_event_get_state_dynamic_by_id(id))
 105
 106 /**
 107  * trace_event_get_state_backends:
 108  * @id: Event identifier name.
 109  *
 110  * Get the tracing state of an event, both static and dynamic state from all
 111  * compiled-in backends.
 112  *
 113  * If the event has the disabled property, the check will have no performance
 114  * impact.
 115  *
 116  * Returns: true if at least one backend has the event enabled and the event
 117  * does not have the disabled property.
 118  */
 119 #define trace_event_get_state_backends(id)              \
 120     ((id ##_ENABLED) && id ##_BACKEND_DSTATE())
 121
 122 /**
 123  * trace_event_get_vcpu_state:
 124  * @vcpu: Target vCPU.
 125  * @id: Event identifier name.
 126  *
 127  * Get the tracing state of an event (both static and dynamic) for the given
 128  * vCPU.
 129  *
 130  * If the event has the disabled property, the check will have no performance
 131  * impact.
 132  */
 133 #define trace_event_get_vcpu_state(vcpu, id)                            \
 134     ((id ##_ENABLED) &&                                                 \
 135      trace_event_get_vcpu_state_dynamic_by_vcpu_id(                     \
 136          vcpu, _ ## id ## _EVENT.vcpu_id))
 137
 138 /**
 139  * trace_event_get_state_static:
 140  * @id: Event identifier.
 141  *
 142  * Get the static tracing state of an event.
 143  *
 144  * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will
 145  * be set to 1 or 0 according to the presence of the disabled property).
 146  */
 147 static bool trace_event_get_state_static(TraceEvent *ev);
 148
 149 /**
 150  * trace_event_get_state_dynamic:
 151  *
 152  * Get the dynamic tracing state of an event.
 153  *
 154  * If the event has the 'vcpu' property, gets the OR'ed state of all vCPUs.
 155  */
 156 static bool trace_event_get_state_dynamic(TraceEvent *ev);
 157
 158 /**
 159  * trace_event_get_vcpu_state_dynamic:
 160  *
 161  * Get the dynamic tracing state of an event for the given vCPU.
 162  */
 163 static bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu, TraceEvent *ev);
 164
 165
 166 /**
 167  * trace_event_set_state_dynamic:
 168  *
 169  * Set the dynamic tracing state of an event.
 170  *
 171  * If the event has the 'vcpu' property, sets the state on all vCPUs.
 172  *
 173  * Pre-condition: trace_event_get_state_static(ev) == true
 174  */
 175 void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 176
 177 /**
 178  * trace_event_set_vcpu_state_dynamic:
 179  *
 180  * Set the dynamic tracing state of an event for the given vCPU.
 181  *
 182  * Pre-condition: trace_event_get_vcpu_state_static(ev) == true
 183  *
 184  * Note: Changes for execution-time events with the 'tcg' property will not be
 185  *       propagated until the next TB is executed (iff executing in TCG mode).
 186  */
 187 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
 188                                         TraceEvent *ev, bool state);
 189
 190
 191
 192 /**
 193  * trace_init_backends:
 194  * @file:   Name of trace output file; may be NULL.
 195  *          Corresponds to commandline option "--trace file=...".
 196  *
 197  * Initialize the tracing backend.
 198  *
 199  * Returns: Whether the backends could be successfully initialized.
 200  */
 201 bool trace_init_backends(void);
 202
 203 /**
 204  * trace_init_file:
 205  * @file:   Name of trace output file; may be NULL.
 206  *          Corresponds to commandline option "--trace file=...".
 207  *
 208  * Record the name of the output file for the tracing backend.
 209  * Exits if no selected backend does not support specifying the
 210  * output file, and a non-NULL file was passed.
 211  */
 212 void trace_init_file(const char *file);
 213
 214 /**
 215  * trace_init_vcpu:
 216  * @vcpu: Added vCPU.
 217  *
 218  * Set initial dynamic event state for a hot-plugged vCPU.
 219  */
 220 void trace_init_vcpu(CPUState *vcpu);
 221
 222 /**
 223  * trace_fini_vcpu:
 224  * @vcpu: Removed vCPU.
 225  *
 226  * Disable dynamic event state for a hot-unplugged vCPU.
 227  */
 228 void trace_fini_vcpu(CPUState *vcpu);
 229
 230 /**
 231  * trace_list_events:
 232  *
 233  * List all available events.
 234  */
 235 void trace_list_events(void);
 236
 237 /**
 238  * trace_enable_events:
 239  * @line_buf: A string with a glob pattern of events to be enabled or,
 240  *            if the string starts with '-', disabled.
 241  *
 242  * Enable or disable matching events.
 243  */
 244 void trace_enable_events(const char *line_buf);
 245
 246 /**
 247  * Definition of QEMU options describing trace subsystem configuration
 248  */
 249 extern QemuOptsList qemu_trace_opts;
 250
 251 /**
 252  * trace_opt_parse:
 253  * @optarg: A string argument of --trace command line argument
 254  *
 255  * Initialize tracing subsystem.
 256  *
 257  * Returns the filename to save trace to.  It must be freed with g_free().
 258  */
 259 char *trace_opt_parse(const char *optarg);
 260
 261 /**
 262  * trace_get_vcpu_event_count:
 263  *
 264  * Return the number of known vcpu-specific events
 265  */
 266 uint32_t trace_get_vcpu_event_count(void);
 267
 268
 269 #include "control-internal.h"
 270
 271 #endif /* TRACE__CONTROL_H */