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