qemu/trace/control-target.c

150 lines
4.3 KiB
C

/*
* Interface for configuring and controlling the state of tracing events.
*
* Copyright (C) 2014-2017 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "cpu.h"
#include "trace-root.h"
#include "trace/control.h"
void trace_event_set_state_dynamic_init(TraceEvent *ev, bool state)
{
bool state_pre;
assert(trace_event_get_state_static(ev));
/*
* We ignore the "vcpu" property here, since no vCPUs have been created
* yet. Then dstate can only be 1 or 0.
*/
state_pre = *ev->dstate;
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
*ev->dstate = 1;
} else {
trace_events_enabled_count--;
*ev->dstate = 0;
}
}
}
void trace_event_set_state_dynamic(TraceEvent *ev, bool state)
{
CPUState *vcpu;
assert(trace_event_get_state_static(ev));
if (trace_event_is_vcpu(ev) && likely(first_cpu != NULL)) {
CPU_FOREACH(vcpu) {
trace_event_set_vcpu_state_dynamic(vcpu, ev, state);
}
} else {
/*
* Without the "vcpu" property, dstate can only be 1 or 0. With it, we
* haven't instantiated any vCPU yet, so we will set a global state
* instead, and trace_init_vcpu will reconcile it afterwards.
*/
bool state_pre = *ev->dstate;
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
*ev->dstate = 1;
} else {
trace_events_enabled_count--;
*ev->dstate = 0;
}
}
}
}
static void trace_event_synchronize_vcpu_state_dynamic(
CPUState *vcpu, run_on_cpu_data ignored)
{
bitmap_copy(vcpu->trace_dstate, vcpu->trace_dstate_delayed,
CPU_TRACE_DSTATE_MAX_EVENTS);
cpu_tb_jmp_cache_clear(vcpu);
}
void trace_event_set_vcpu_state_dynamic(CPUState *vcpu,
TraceEvent *ev, bool state)
{
uint32_t vcpu_id;
bool state_pre;
assert(trace_event_get_state_static(ev));
assert(trace_event_is_vcpu(ev));
vcpu_id = trace_event_get_vcpu_id(ev);
state_pre = test_bit(vcpu_id, vcpu->trace_dstate);
if (state_pre != state) {
if (state) {
trace_events_enabled_count++;
set_bit(vcpu_id, vcpu->trace_dstate_delayed);
(*ev->dstate)++;
} else {
trace_events_enabled_count--;
clear_bit(vcpu_id, vcpu->trace_dstate_delayed);
(*ev->dstate)--;
}
if (vcpu->created) {
/*
* Delay changes until next TB; we want all TBs to be built from a
* single set of dstate values to ensure consistency of generated
* tracing code.
*/
async_run_on_cpu(vcpu, trace_event_synchronize_vcpu_state_dynamic,
RUN_ON_CPU_NULL);
} else {
trace_event_synchronize_vcpu_state_dynamic(vcpu, RUN_ON_CPU_NULL);
}
}
}
static bool adding_first_cpu1(void)
{
CPUState *cpu;
size_t count = 0;
CPU_FOREACH(cpu) {
count++;
if (count > 1) {
return false;
}
}
return true;
}
static bool adding_first_cpu(void)
{
bool res;
cpu_list_lock();
res = adding_first_cpu1();
cpu_list_unlock();
return res;
}
void trace_init_vcpu(CPUState *vcpu)
{
TraceEventIter iter;
TraceEvent *ev;
trace_event_iter_init(&iter, NULL);
while ((ev = trace_event_iter_next(&iter)) != NULL) {
if (trace_event_is_vcpu(ev) &&
trace_event_get_state_static(ev) &&
trace_event_get_state_dynamic(ev)) {
if (adding_first_cpu()) {
/* check preconditions */
assert(*ev->dstate == 1);
/* disable early-init state ... */
*ev->dstate = 0;
trace_events_enabled_count--;
/* ... and properly re-enable */
trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
} else {
trace_event_set_vcpu_state_dynamic(vcpu, ev, true);
}
}
}
trace_guest_cpu_enter(vcpu);
}