From: "Emilio G. Cota" <c...@braap.org>
Suggested-by: Alex Bennée <alex.ben...@linaro.org>
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
Signed-off-by: Emilio G. Cota <c...@braap.org>
[AJB: moved inside start/end_exclusive fns + cleanup]
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
v4
- -> cpu_in_exclusive_context
- moved inside start/end exclusive
- fixed up cpu_exec_step_atomic
---
accel/tcg/cpu-exec.c | 5 +----
cpus-common.c | 4 ++++
include/qom/cpu.h | 13 +++++++++++++
3 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 6c85c3ee1e9..ab9dfd4f908 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -239,8 +239,6 @@ void cpu_exec_step_atomic(CPUState *cpu)
uint32_t flags;
uint32_t cflags = 1;
uint32_t cf_mask = cflags & CF_HASH_MASK;
- /* volatile because we modify it between setjmp and longjmp */
- volatile bool in_exclusive_region = false;
if (sigsetjmp(cpu->jmp_env, 0) == 0) {
tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags, cf_mask);
@@ -254,7 +252,6 @@ void cpu_exec_step_atomic(CPUState *cpu)
/* Since we got here, we know that parallel_cpus must be true. */
parallel_cpus = false;
- in_exclusive_region = true;
cc->cpu_exec_enter(cpu);
/* execute the generated code */
trace_exec_tb(tb, pc);
@@ -274,7 +271,7 @@ void cpu_exec_step_atomic(CPUState *cpu)
assert_no_pages_locked();
}
- if (in_exclusive_region) {
+ if (cpu_in_exclusive_context(cpu)) {
/* We might longjump out of either the codegen or the
* execution, so must make sure we only end the exclusive
* region if we started it.
diff --git a/cpus-common.c b/cpus-common.c
index 3ca58c64e80..e87400834be 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -208,11 +208,15 @@ void start_exclusive(void)
* section until end_exclusive resets pending_cpus to 0.
*/
qemu_mutex_unlock(&qemu_cpu_list_lock);
+
+ current_cpu->in_exclusive_context = true;
}
/* Finish an exclusive operation. */
void end_exclusive(void)
{
+ current_cpu->in_exclusive_context = false;
+
qemu_mutex_lock(&qemu_cpu_list_lock);
atomic_set(&pending_cpus, 0);
qemu_cond_broadcast(&exclusive_resume);
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 5ee0046b629..65a0926c49a 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -373,6 +373,7 @@ struct CPUState {
bool unplug;
bool crash_occurred;
bool exit_request;
+ bool in_exclusive_context;
uint32_t cflags_next_tb;
/* updates protected by BQL */
uint32_t interrupt_request;
@@ -785,6 +786,18 @@ void async_run_on_cpu(CPUState *cpu, run_on_cpu_func func,
run_on_cpu_data data)
*/
void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func func,
run_on_cpu_data data);
+/**
+ * cpu_in_exclusive_context()
+ * @cpu: The vCPU to check
+ *
+ * Returns true if @cpu is an exclusive context, for example running
+ * something which has previously been queued via async_safe_run_on_cpu().
+ */
+static inline bool cpu_in_exclusive_context(const CPUState *cpu)
+{
+ return cpu->in_exclusive_context;
+}
+
/**
* qemu_get_cpu:
* @index: The CPUState@cpu_index value of the CPU to obtain.
--
2.20.1
