From: KONRAD Frederic <fred.kon...@greensocs.com>
This removes exit_request global and adds a variable in CPUState for this.
Only the flag for the first cpu is used for the moment as we are still with one
TCG thread.
Signed-off-by: KONRAD Frederic <fred.kon...@greensocs.com>
---
cpu-exec.c | 15 ---------------
cpus.c | 17 ++++++++++++++---
2 files changed, 14 insertions(+), 18 deletions(-)
diff --git a/cpu-exec.c b/cpu-exec.c
index a012e9d..21a7b96 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -363,8 +363,6 @@ static void cpu_handle_debug_exception(CPUState *cpu)
/* main execution loop */
-volatile sig_atomic_t exit_request;
-
int cpu_exec(CPUState *cpu)
{
CPUClass *cc = CPU_GET_CLASS(cpu);
@@ -402,20 +400,8 @@ int cpu_exec(CPUState *cpu)
}
current_cpu = cpu;
- /* As long as current_cpu is null, up to the assignment just above,
- * requests by other threads to exit the execution loop are expected to
- * be issued using the exit_request global. We must make sure that our
- * evaluation of the global value is performed past the current_cpu
- * value transition point, which requires a memory barrier as well as
- * an instruction scheduling constraint on modern architectures. */
- smp_mb();
-
rcu_read_lock();
- if (unlikely(exit_request)) {
- cpu->exit_request = 1;
- }
-
cc->cpu_exec_enter(cpu);
/* Calculate difference between guest clock and host clock.
@@ -504,7 +490,6 @@ int cpu_exec(CPUState *cpu)
}
}
if (unlikely(cpu->exit_request)) {
- cpu->exit_request = 0;
cpu->exception_index = EXCP_INTERRUPT;
cpu_loop_exit(cpu);
}
diff --git a/cpus.c b/cpus.c
index 154a081..2de9eae 100644
--- a/cpus.c
+++ b/cpus.c
@@ -139,6 +139,8 @@ typedef struct TimersState {
} TimersState;
static TimersState timers_state;
+/* CPU associated to this thread. */
+static __thread CPUState *tcg_thread_cpu;
int64_t cpu_get_icount_raw(void)
{
@@ -663,12 +665,18 @@ static void cpu_handle_guest_debug(CPUState *cpu)
cpu->stopped = true;
}
+/**
+ * cpu_signal
+ * Signal handler when using TCG.
+ */
static void cpu_signal(int sig)
{
if (current_cpu) {
cpu_exit(current_cpu);
}
- exit_request = 1;
+
+ /* FIXME: We might want to check if the cpu is running? */
+ tcg_thread_cpu->exit_request = true;
}
#ifdef CONFIG_LINUX
@@ -1151,6 +1159,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
CPUState *cpu = arg;
qemu_mutex_lock_iothread();
+ tcg_thread_cpu = cpu;
qemu_tcg_init_cpu_signals();
qemu_thread_get_self(cpu->thread);
@@ -1480,7 +1489,8 @@ static void tcg_exec_all(void)
if (next_cpu == NULL) {
next_cpu = first_cpu;
}
- for (; next_cpu != NULL && !exit_request; next_cpu = CPU_NEXT(next_cpu)) {
+ for (; next_cpu != NULL && !first_cpu->exit_request;
+ next_cpu = CPU_NEXT(next_cpu)) {
CPUState *cpu = next_cpu;
qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
@@ -1496,7 +1506,8 @@ static void tcg_exec_all(void)
break;
}
}
- exit_request = 0;
+
+ first_cpu->exit_request = 0;
}
void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
--
1.9.0
