trace/control-target.c

   1 /*
   2  * Interface for configuring and controlling the state of tracing events.
   3  *
   4  * Copyright (C) 2014-2017 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) && likely(first_cpu != NULL)) {
  42         CPU_FOREACH(vcpu) {
  43             trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
  44         }
  45     } else {
  46         /*
  47          * Without the "vcpu" property, dstate can only be 1 or 0. With it, we
  48          * haven't instantiated any vCPU yet, so we will set a global state
  49          * instead, and trace_init_vcpu will reconcile it afterwards.
  50          */
  51         bool state_pre = *ev->dstate;
  52         if (state_pre != state) {
  53             if (state) {
  54                 trace_events_enabled_count++;
  55                 *ev->dstate = 1;
  56             } else {
  57                 trace_events_enabled_count--;
  58                 *ev->dstate = 0;
  59             }
  60         }
  61     }
  62 }
  63
  64 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
  65                                         TraceEvent *ev, bool state)
  66 {
  67     uint32_t vcpu_id;
  68     bool state_pre;
  69     assert(trace_event_get_state_static(ev));
  70     assert(trace_event_is_vcpu(ev));
  71     vcpu_id = trace_event_get_vcpu_id(ev);
  72     state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
  73     if (state_pre != state) {
  74         if (state) {
  75             trace_events_enabled_count++;
  76             set_bit(vcpu_id, vcpu->trace_dstate);
  77             (*ev->dstate)++;
  78         } else {
  79             trace_events_enabled_count--;
  80             clear_bit(vcpu_id, vcpu->trace_dstate);
  81             (*ev->dstate)--;
  82         }
  83     }
  84 }
  85
  86 static bool adding_first_cpu1(void)
  87 {
  88     CPUState *cpu;
  89     size_t count = 0;
  90     CPU_FOREACH(cpu) {
  91         count++;
  92         if (count > 1) {
  93             return false;
  94         }
  95     }
  96     return true;
  97 }
  98
  99 static bool adding_first_cpu(void)
 100 {
 101     bool res;
 102     cpu_list_lock();
 103     res = adding_first_cpu1();
 104     cpu_list_unlock();
 105     return res;
 106 }
 107
 108 void trace_init_vcpu(CPUState *vcpu)
 109 {
 110     TraceEventIter iter;
 111     TraceEvent *ev;
 112     trace_event_iter_init(&iter, NULL);
 113     while ((ev = trace_event_iter_next(&iter)) != NULL) {
 114         if (trace_event_is_vcpu(ev) &&
 115             trace_event_get_state_static(ev) &&
 116             trace_event_get_state_dynamic(ev)) {
 117             if (adding_first_cpu()) {
 118                 /* check preconditions */
 119                 assert(*ev->dstate == 1);
 120                 /* disable early-init state ... */
 121                 *ev->dstate = 0;
 122                 trace_events_enabled_count--;
 123                 /* ... and properly re-enable */
 124                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
 125             } else {
 126                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
 127             }
 128         }
 129     }
 130     trace_guest_cpu_enter(vcpu);
 131 }