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 cpu_tb_jmp_cache_clear(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 } 150