trace/control-target.c

   1 /*
   2  * Interface for configuring and controlling the state of tracing events.
   3  *
   4  * Copyright (C) 2014-2016 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 #include "qemu/osdep.h"
  11 #include "cpu.h"
  12 #include "trace-root.h"
  13 #include "trace/control.h"
  14 #include "translate-all.h"
  15
  16
  17 void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
  18 {
  19     bool state_pre;
  20     assert(trace_event_get_state_static(ev));
  21     /*
  22      * We ignore the "vcpu" property here, since no vCPUs have been created
  23      * yet. Then dstate can only be 1 or 0.
  24      */
  25     state_pre = *ev->dstate;
  26     if (state_pre != state) {
  27         if (state) {
  28             trace_events_enabled_count++;
  29             *ev->dstate = 1;
  30         } else {
  31             trace_events_enabled_count--;
  32             *ev->dstate = 0;
  33         }
  34     }
  35 }
  36
  37 void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
  38 {
  39     CPUState *vcpu;
  40     assert(trace_event_get_state_static(ev));
  41     if (trace_event_is_vcpu(ev)) {
  42         CPU_FOREACH(vcpu) {
  43             trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
  44         }
  45     } else {
  46         /* Without the "vcpu" property, dstate can only be 1 or 0 */
  47         bool state_pre = *ev->dstate;
  48         if (state_pre != state) {
  49             if (state) {
  50                 trace_events_enabled_count++;
  51                 *ev->dstate = 1;
  52             } else {
  53                 trace_events_enabled_count--;
  54                 *ev->dstate = 0;
  55             }
  56         }
  57     }
  58 }
  59
  60 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
  61                                         TraceEvent *ev, bool state)
  62 {
  63     uint32_t vcpu_id;
  64     bool state_pre;
  65     assert(trace_event_get_state_static(ev));
  66     assert(trace_event_is_vcpu(ev));
  67     vcpu_id = trace_event_get_vcpu_id(ev);
  68     state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
  69     if (state_pre != state) {
  70         if (state) {
  71             trace_events_enabled_count++;
  72             set_bit(vcpu_id, vcpu->trace_dstate);
  73             (*ev->dstate)++;
  74         } else {
  75             trace_events_enabled_count--;
  76             clear_bit(vcpu_id, vcpu->trace_dstate);
  77             (*ev->dstate)--;
  78         }
  79     }
  80 }
  81
  82 static bool adding_first_cpu1(void)
  83 {
  84     CPUState *cpu;
  85     size_t count = 0;
  86     CPU_FOREACH(cpu) {
  87         count++;
  88         if (count > 1) {
  89             return false;
  90         }
  91     }
  92     return true;
  93 }
  94
  95 static bool adding_first_cpu(void)
  96 {
  97     bool res;
  98     cpu_list_lock();
  99     res = adding_first_cpu1();
 100     cpu_list_unlock();
 101     return res;
 102 }
 103
 104 void trace_init_vcpu(CPUState *vcpu)
 105 {
 106     TraceEventIter iter;
 107     TraceEvent *ev;
 108     trace_event_iter_init(&iter, NULL);
 109     while ((ev = trace_event_iter_next(&iter)) != NULL) {
 110         if (trace_event_is_vcpu(ev) &&
 111             trace_event_get_state_static(ev) &&
 112             trace_event_get_state_dynamic(ev)) {
 113             if (adding_first_cpu()) {
 114                 /* check preconditions */
 115                 assert(*ev->dstate == 1);
 116                 /* disable early-init state ... */
 117                 *ev->dstate = 0;
 118                 trace_events_enabled_count--;
 119                 /* ... and properly re-enable */
 120                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
 121             } else {
 122                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
 123             }
 124         }
 125     }
 126     trace_guest_cpu_enter(vcpu);
 127 }