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