[v11,12/24] tcg: handle EXCP_ATOMIC exception for system emulation

Message ID 20170209170904.5713-13-alex.bennee@linaro.org
State New
Headers show
Series
  • MTTCG Base enabling patches with ARM enablement
Related show

Commit Message

Alex Bennée Feb. 9, 2017, 5:08 p.m.
From: Pranith Kumar <bobby.prani@gmail.com>


The patch enables handling atomic code in the guest. This should be
preferably done in cpu_handle_exception(), but the current assumptions
regarding when we can execute atomic sections cause a deadlock.

Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>

[AJB: tweak title]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Reviewed-by: Richard Henderson <rth@twiddle.net>

---
 cpus.c | 9 +++++++++
 1 file changed, 9 insertions(+)

-- 
2.11.0

Patch

diff --git a/cpus.c b/cpus.c
index 25897edbd3..cb44544fcf 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1347,6 +1347,11 @@  static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
                 if (r == EXCP_DEBUG) {
                     cpu_handle_guest_debug(cpu);
                     break;
+                } else if (r == EXCP_ATOMIC) {
+                    qemu_mutex_unlock_iothread();
+                    cpu_exec_step_atomic(cpu);
+                    qemu_mutex_lock_iothread();
+                    break;
                 }
             } else if (cpu->stop) {
                 if (cpu->unplug) {
@@ -1457,6 +1462,10 @@  static void *qemu_tcg_cpu_thread_fn(void *arg)
                  */
                 g_assert(cpu->halted);
                 break;
+            case EXCP_ATOMIC:
+                qemu_mutex_unlock_iothread();
+                cpu_exec_step_atomic(cpu);
+                qemu_mutex_lock_iothread();
             default:
                 /* Ignore everything else? */
                 break;