Like cpu_in_exclusive_context, but also true if
there is no other cpu against which we could race.
Use it in tb_flush as a direct replacement.
Use it in cpu_loop_exit_atomic to ensure that there
is no loop against cpu_exec_step_atomic.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
accel/tcg/internal.h | 5 +++++
accel/tcg/cpu-exec-common.c | 3 +++
accel/tcg/tb-maint.c | 2 +-
3 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/accel/tcg/internal.h b/accel/tcg/internal.h
index cb13bade4f..f06bf58e7a 100644
--- a/accel/tcg/internal.h
+++ b/accel/tcg/internal.h
@@ -119,4 +119,9 @@ static inline target_ulong log_pc(CPUState *cpu, const
TranslationBlock *tb)
#endif
}
+static inline bool cpu_in_serial_context(CPUState *cs)
+{
+ return !(cs->tcg_cflags & CF_PARALLEL) || cpu_in_exclusive_context(cs);
+}
+
#endif /* ACCEL_TCG_INTERNAL_H */
diff --git a/accel/tcg/cpu-exec-common.c b/accel/tcg/cpu-exec-common.c
index c7bc8c6efa..2fb4454c7a 100644
--- a/accel/tcg/cpu-exec-common.c
+++ b/accel/tcg/cpu-exec-common.c
@@ -21,6 +21,7 @@
#include "sysemu/cpus.h"
#include "sysemu/tcg.h"
#include "exec/exec-all.h"
+#include "internal.h"
bool tcg_allowed;
@@ -78,6 +79,8 @@ void cpu_loop_exit_restore(CPUState *cpu, uintptr_t pc)
void cpu_loop_exit_atomic(CPUState *cpu, uintptr_t pc)
{
+ /* Prevent looping if already executing in a serial context. */
+ g_assert(!cpu_in_serial_context(cpu));
cpu->exception_index = EXCP_ATOMIC;
cpu_loop_exit_restore(cpu, pc);
}
diff --git a/accel/tcg/tb-maint.c b/accel/tcg/tb-maint.c
index 0cdb35548c..a7c067628c 100644
--- a/accel/tcg/tb-maint.c
+++ b/accel/tcg/tb-maint.c
@@ -119,7 +119,7 @@ void tb_flush(CPUState *cpu)
if (tcg_enabled()) {
unsigned tb_flush_count = qatomic_mb_read(&tb_ctx.tb_flush_count);
- if (cpu_in_exclusive_context(cpu)) {
+ if (cpu_in_serial_context(cpu)) {
do_tb_flush(cpu, RUN_ON_CPU_HOST_INT(tb_flush_count));
} else {
async_safe_run_on_cpu(cpu, do_tb_flush,
--
2.34.1
