@@ -1065,14 +1065,6 @@ static int __vhost_add_used_n(struct vhost_virtqueue *vq,
vq_err(vq, "Failed to write used");
return -EFAULT;
}
- /* Make sure buffer is written before we update index. */
- smp_wmb();
- if (put_user(vq->last_used_idx + count, &vq->used->idx)) {
- vq_err(vq, "Failed to increment used idx");
- return -EFAULT;
- }
- if (unlikely(vq->log_used))
- vhost_log_used(vq, used);
vq->last_used_idx += count;
return 0;
}
@@ -1093,7 +1085,17 @@ int vhost_add_used_n(struct vhost_virtqueue *vq, struct vring_used_elem *heads,
heads += n;
count -= n;
}
- return __vhost_add_used_n(vq, heads, count);
+ r = __vhost_add_used_n(vq, heads, count);
+
+ /* Make sure buffer is written before we update index. */
+ smp_wmb();
+ if (put_user(vq->last_used_idx, &vq->used->idx)) {
+ vq_err(vq, "Failed to increment used idx");
+ return -EFAULT;
+ }
+ if (unlikely(vq->log_used))
+ vhost_log_used(vq, vq->used->ring + start);
+ return r;
}
/* This actually signals the guest, using eventfd. */