1 files changed, 48 insertions, 11 deletions

diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index 1fe93e93f5..1f5b3dd31f 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -33,7 +33,7 @@
 #define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \
 					     __GFP_NOMEMALLOC)
 /* The order of free page blocks to report to host */
-#define VIRTIO_BALLOON_HINT_BLOCK_ORDER MAX_ORDER
+#define VIRTIO_BALLOON_HINT_BLOCK_ORDER MAX_PAGE_ORDER
 /* The size of a free page block in bytes */
 #define VIRTIO_BALLOON_HINT_BLOCK_BYTES \
 	(1 << (VIRTIO_BALLOON_HINT_BLOCK_ORDER + PAGE_SHIFT))
@@ -119,6 +119,11 @@ struct virtio_balloon {
 	/* Free page reporting device */
 	struct virtqueue *reporting_vq;
 	struct page_reporting_dev_info pr_dev_info;
+
+	/* State for keeping the wakeup_source active while adjusting the balloon */
+	spinlock_t adjustment_lock;
+	bool adjustment_signal_pending;
+	bool adjustment_in_progress;
 };
 
 static const struct virtio_device_id id_table[] = {
@@ -437,6 +442,31 @@ static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
 	queue_work(vb->balloon_wq, &vb->report_free_page_work);
 }
 
+static void start_update_balloon_size(struct virtio_balloon *vb)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&vb->adjustment_lock, flags);
+	vb->adjustment_signal_pending = true;
+	if (!vb->adjustment_in_progress) {
+		vb->adjustment_in_progress = true;
+		pm_stay_awake(vb->vdev->dev.parent);
+	}
+	spin_unlock_irqrestore(&vb->adjustment_lock, flags);
+
+	queue_work(system_freezable_wq, &vb->update_balloon_size_work);
+}
+
+static void end_update_balloon_size(struct virtio_balloon *vb)
+{
+	spin_lock_irq(&vb->adjustment_lock);
+	if (!vb->adjustment_signal_pending && vb->adjustment_in_progress) {
+		vb->adjustment_in_progress = false;
+		pm_relax(vb->vdev->dev.parent);
+	}
+	spin_unlock_irq(&vb->adjustment_lock);
+}
+
 static void virtballoon_changed(struct virtio_device *vdev)
 {
 	struct virtio_balloon *vb = vdev->priv;
@@ -444,8 +474,7 @@ static void virtballoon_changed(struct virtio_device *vdev)
 
 	spin_lock_irqsave(&vb->stop_update_lock, flags);
 	if (!vb->stop_update) {
-		queue_work(system_freezable_wq,
-			   &vb->update_balloon_size_work);
+		start_update_balloon_size(vb);
 		virtio_balloon_queue_free_page_work(vb);
 	}
 	spin_unlock_irqrestore(&vb->stop_update_lock, flags);
@@ -476,19 +505,25 @@ static void update_balloon_size_func(struct work_struct *work)
 
 	vb = container_of(work, struct virtio_balloon,
 			  update_balloon_size_work);
-	diff = towards_target(vb);
 
-	if (!diff)
-		return;
+	spin_lock_irq(&vb->adjustment_lock);
+	vb->adjustment_signal_pending = false;
+	spin_unlock_irq(&vb->adjustment_lock);
 
-	if (diff > 0)
-		diff -= fill_balloon(vb, diff);
-	else
-		diff += leak_balloon(vb, -diff);
-	update_balloon_size(vb);
+	diff = towards_target(vb);
+
+	if (diff) {
+		if (diff > 0)
+			diff -= fill_balloon(vb, diff);
+		else
+			diff += leak_balloon(vb, -diff);
+		update_balloon_size(vb);
+	}
 
 	if (diff)
 		queue_work(system_freezable_wq, work);
+	else
+		end_update_balloon_size(vb);
 }
 
 static int init_vqs(struct virtio_balloon *vb)
@@ -992,6 +1027,8 @@ static int virtballoon_probe(struct virtio_device *vdev)
 			goto out_unregister_oom;
 	}
 
+	spin_lock_init(&vb->adjustment_lock);
+
 	virtio_device_ready(vdev);
 
 	if (towards_target(vb))