diff --git a/job.c b/job.c
index 20f0d8b..7365db8 100644
--- a/job.c
+++ b/job.c
@@ -32,6 +32,12 @@
 #include "trace/trace-root.h"
 #include "qapi/qapi-events-job.h"
 
+/*
+ * job_mutex protects the jobs list, but also makes the
+ * struct job fields thread-safe.
+ */
+QemuMutex job_mutex;
+
 static QLIST_HEAD(, Job) jobs = QLIST_HEAD_INITIALIZER(jobs);
 
 /* Job State Transition Table */
@@ -74,17 +80,22 @@
     int refcnt;
 };
 
-/* Right now, this mutex is only needed to synchronize accesses to job->busy
- * and job->sleep_timer, such as concurrent calls to job_do_yield and
- * job_enter. */
-static QemuMutex job_mutex;
+void job_lock(void)
+{
+    /* nop */
+}
 
-static void job_lock(void)
+void job_unlock(void)
+{
+    /* nop */
+}
+
+static void real_job_lock(void)
 {
     qemu_mutex_lock(&job_mutex);
 }
 
-static void job_unlock(void)
+static void real_job_unlock(void)
 {
     qemu_mutex_unlock(&job_mutex);
 }
@@ -450,21 +461,21 @@
         return;
     }
 
-    job_lock();
+    real_job_lock();
     if (job->busy) {
-        job_unlock();
+        real_job_unlock();
         return;
     }
 
     if (fn && !fn(job)) {
-        job_unlock();
+        real_job_unlock();
         return;
     }
 
     assert(!job->deferred_to_main_loop);
     timer_del(&job->sleep_timer);
     job->busy = true;
-    job_unlock();
+    real_job_unlock();
     aio_co_enter(job->aio_context, job->co);
 }
 
@@ -481,13 +492,13 @@
  * called explicitly. */
 static void coroutine_fn job_do_yield(Job *job, uint64_t ns)
 {
-    job_lock();
+    real_job_lock();
     if (ns != -1) {
         timer_mod(&job->sleep_timer, ns);
     }
     job->busy = false;
     job_event_idle(job);
-    job_unlock();
+    real_job_unlock();
     qemu_coroutine_yield();
 
     /* Set by job_enter_cond() before re-entering the coroutine.  */