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 dynamic).
 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_vcpu_state:
 109  * @vcpu: Target vCPU.
 110  * @id: Event identifier name.
 111  *
 112  * Get the tracing state of an event (both static and dynamic) for the given
 113  * vCPU.
 114  *
 115  * If the event has the disabled property, the check will have no performance
 116  * impact.
 117  */
 118 #define trace_event_get_vcpu_state(vcpu, id)                            \
 119     ((id ##_ENABLED) &&                                                 \
 120      trace_event_get_vcpu_state_dynamic_by_vcpu_id(                     \
 121          vcpu, _ ## id ## _EVENT.vcpu_id))
 122
 123 /**
 124  * trace_event_get_state_static:
 125  * @id: Event identifier.
 126  *
 127  * Get the static tracing state of an event.
 128  *
 129  * Use the define 'TRACE_${EVENT_NAME}_ENABLED' for compile-time checks (it will
 130  * be set to 1 or 0 according to the presence of the disabled property).
 131  */
 132 static bool trace_event_get_state_static(TraceEvent *ev);
 133
 134 /**
 135  * trace_event_get_state_dynamic:
 136  *
 137  * Get the dynamic tracing state of an event.
 138  *
 139  * If the event has the 'vcpu' property, gets the OR'ed state of all vCPUs.
 140  */
 141 static bool trace_event_get_state_dynamic(TraceEvent *ev);
 142
 143 /**
 144  * trace_event_get_vcpu_state_dynamic:
 145  *
 146  * Get the dynamic tracing state of an event for the given vCPU.
 147  */
 148 static bool trace_event_get_vcpu_state_dynamic(CPUState *vcpu, TraceEvent *ev);
 149
 150
 151 /**
 152  * trace_event_set_state_dynamic:
 153  *
 154  * Set the dynamic tracing state of an event.
 155  *
 156  * If the event has the 'vcpu' property, sets the state on all vCPUs.
 157  *
 158  * Pre-condition: trace_event_get_state_static(ev) == true
 159  */
 160 void trace_event_set_state_dynamic(TraceEvent *ev, bool state);
 161
 162 /**
 163  * trace_event_set_vcpu_state_dynamic:
 164  *
 165  * Set the dynamic tracing state of an event for the given vCPU.
 166  *
 167  * Pre-condition: trace_event_get_vcpu_state_static(ev) == true
 168  */
 169 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
 170                                         TraceEvent *ev, bool state);
 171
 172
 173
 174 /**
 175  * trace_init_backends:
 176  * @file:   Name of trace output file; may be NULL.
 177  *          Corresponds to commandline option "-trace file=...".
 178  *
 179  * Initialize the tracing backend.
 180  *
 181  * Returns: Whether the backends could be successfully initialized.
 182  */
 183 bool trace_init_backends(void);
 184
 185 /**
 186  * trace_init_file:
 187  * @file:   Name of trace output file; may be NULL.
 188  *          Corresponds to commandline option "-trace file=...".
 189  *
 190  * Record the name of the output file for the tracing backend.
 191  * Exits if no selected backend does not support specifying the
 192  * output file, and a non-NULL file was passed.
 193  */
 194 void trace_init_file(const char *file);
 195
 196 /**
 197  * trace_init_vcpu:
 198  * @vcpu: Added vCPU.
 199  *
 200  * Set initial dynamic event state for a hot-plugged vCPU.
 201  */
 202 void trace_init_vcpu(CPUState *vcpu);
 203
 204 /**
 205  * trace_fini_vcpu:
 206  * @vcpu: Removed vCPU.
 207  *
 208  * Disable dynamic event state for a hot-unplugged vCPU.
 209  */
 210 void trace_fini_vcpu(CPUState *vcpu);
 211
 212 /**
 213  * trace_list_events:
 214  *
 215  * List all available events.
 216  */
 217 void trace_list_events(void);
 218
 219 /**
 220  * trace_enable_events:
 221  * @line_buf: A string with a glob pattern of events to be enabled or,
 222  *            if the string starts with '-', disabled.
 223  *
 224  * Enable or disable matching events.
 225  */
 226 void trace_enable_events(const char *line_buf);
 227
 228 /**
 229  * Definition of QEMU options describing trace subsystem configuration
 230  */
 231 extern QemuOptsList qemu_trace_opts;
 232
 233 /**
 234  * trace_opt_parse:
 235  * @optarg: A string argument of --trace command line argument
 236  *
 237  * Initialize tracing subsystem.
 238  *
 239  * Returns the filename to save trace to.  It must be freed with g_free().
 240  */
 241 char *trace_opt_parse(const char *optarg);
 242
 243 /**
 244  * trace_get_vcpu_event_count:
 245  *
 246  * Return the number of known vcpu-specific events
 247  */
 248 uint32_t trace_get_vcpu_event_count(void);
 249
 250
 251 #include "trace/control-internal.h"
 252
 253 #endif /* TRACE__CONTROL_H */