qemu

FORK: QEMU emulator
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control-target.c (4390B)

      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/trace-root.h"
     13 #include "trace/control.h"
     14 
     15 
     16 void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
     17 {
     18     bool state_pre;
     19     assert(trace_event_get_state_static(ev));
     20     /*
     21      * We ignore the "vcpu" property here, since no vCPUs have been created
     22      * yet. Then dstate can only be 1 or 0.
     23      */
     24     state_pre = *ev->dstate;
     25     if (state_pre != state) {
     26         if (state) {
     27             trace_events_enabled_count++;
     28             *ev->dstate = 1;
     29         } else {
     30             trace_events_enabled_count--;
     31             *ev->dstate = 0;
     32         }
     33     }
     34 }
     35 
     36 void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
     37 {
     38     CPUState *vcpu;
     39     assert(trace_event_get_state_static(ev));
     40     if (trace_event_is_vcpu(ev) && likely(first_cpu != NULL)) {
     41         CPU_FOREACH(vcpu) {
     42             trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
     43         }
     44     } else {
     45         /*
     46          * Without the "vcpu" property, dstate can only be 1 or 0. With it, we
     47          * haven't instantiated any vCPU yet, so we will set a global state
     48          * instead, and trace_init_vcpu will reconcile it afterwards.
     49          */
     50         bool state_pre = *ev->dstate;
     51         if (state_pre != state) {
     52             if (state) {
     53                 trace_events_enabled_count++;
     54                 *ev->dstate = 1;
     55             } else {
     56                 trace_events_enabled_count--;
     57                 *ev->dstate = 0;
     58             }
     59         }
     60     }
     61 }
     62 
     63 static void trace_event_synchronize_vcpu_state_dynamic(
     64     CPUState *vcpu, run_on_cpu_data ignored)
     65 {
     66     bitmap_copy(vcpu->trace_dstate, vcpu->trace_dstate_delayed,
     67                 CPU_TRACE_DSTATE_MAX_EVENTS);
     68     tcg_flush_jmp_cache(vcpu);
     69 }
     70 
     71 void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
     72                                         TraceEvent *ev, bool state)
     73 {
     74     uint32_t vcpu_id;
     75     bool state_pre;
     76     assert(trace_event_get_state_static(ev));
     77     assert(trace_event_is_vcpu(ev));
     78     vcpu_id = trace_event_get_vcpu_id(ev);
     79     state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
     80     if (state_pre != state) {
     81         if (state) {
     82             trace_events_enabled_count++;
     83             set_bit(vcpu_id, vcpu->trace_dstate_delayed);
     84             (*ev->dstate)++;
     85         } else {
     86             trace_events_enabled_count--;
     87             clear_bit(vcpu_id, vcpu->trace_dstate_delayed);
     88             (*ev->dstate)--;
     89         }
     90         if (vcpu->created) {
     91             /*
     92              * Delay changes until next TB; we want all TBs to be built from a
     93              * single set of dstate values to ensure consistency of generated
     94              * tracing code.
     95              */
     96             async_run_on_cpu(vcpu, trace_event_synchronize_vcpu_state_dynamic,
     97                              RUN_ON_CPU_NULL);
     98         } else {
     99             trace_event_synchronize_vcpu_state_dynamic(vcpu, RUN_ON_CPU_NULL);
    100         }
    101     }
    102 }
    103 
    104 static bool adding_first_cpu1(void)
    105 {
    106     CPUState *cpu;
    107     size_t count = 0;
    108     CPU_FOREACH(cpu) {
    109         count++;
    110         if (count > 1) {
    111             return false;
    112         }
    113     }
    114     return true;
    115 }
    116 
    117 static bool adding_first_cpu(void)
    118 {
    119     bool res;
    120     cpu_list_lock();
    121     res = adding_first_cpu1();
    122     cpu_list_unlock();
    123     return res;
    124 }
    125 
    126 void trace_init_vcpu(CPUState *vcpu)
    127 {
    128     TraceEventIter iter;
    129     TraceEvent *ev;
    130     trace_event_iter_init_all(&iter);
    131     while ((ev = trace_event_iter_next(&iter)) != NULL) {
    132         if (trace_event_is_vcpu(ev) &&
    133             trace_event_get_state_static(ev) &&
    134             trace_event_get_state_dynamic(ev)) {
    135             if (adding_first_cpu()) {
    136                 /* check preconditions */
    137                 assert(*ev->dstate == 1);
    138                 /* disable early-init state ... */
    139                 *ev->dstate = 0;
    140                 trace_events_enabled_count--;
    141                 /* ... and properly re-enable */
    142                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
    143             } else {
    144                 trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
    145             }
    146         }
    147     }
    148     trace_guest_cpu_enter(vcpu);
    149 }