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