On 2/16/23 17:18, huang...@chinatelecom.cn wrote:
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 9b26582655..47483cdfa0 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -685,6 +685,15 @@ static uint32_t kvm_dirty_ring_reap_one(KVMState *s,
CPUState *cpu)
uint32_t ring_size = s->kvm_dirty_ring_size;
uint32_t count = 0, fetch = cpu->kvm_fetch_index;
+ /*
+ * It's possible that we race with vcpu creation code where the vcpu is
+ * put onto the vcpus list but not yet initialized the dirty ring
+ * structures. If so, skip it.
+ */
+ if (!cpu->created) {
+ return 0;
+ }
+
Is there a lock that protects cpu->created?
If you don't want to use a lock you need to use qatomic_load_acquire
together with
diff --git a/softmmu/cpus.c b/softmmu/cpus.c
index fed20ffb5dd2..15b64e7f4592 100644
--- a/softmmu/cpus.c
+++ b/softmmu/cpus.c
@@ -525,7 +525,7 @@ void qemu_cond_timedwait_iothread(QemuCond *cond, int ms)
/* signal CPU creation */
void cpu_thread_signal_created(CPUState *cpu)
{
- cpu->created = true;
+ qatomic_store_release(&cpu->created, true);
qemu_cond_signal(&qemu_cpu_cond);
}
Paolo
