[PATCH V4 04/12] vhost: take worker or vq instead of dev for flushing

[Mike Christie <michael.christie@xxxxxxxxxx>]

This patch has the core work flush function take a worker for when we
support multiple workers. It also adds a helper that takes a vq during
flushing so modules can control which vq/worker to flush.

This temp leaves vhost_work_dev_flush. It will be removed when the drivers
are converted in the next patches.

Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
---
 drivers/vhost/vhost.c | 30 +++++++++++++++++++++---------
 drivers/vhost/vhost.h |  1 +
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index f2c6981297d0..e4d765f6c821 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -246,6 +246,26 @@ static void vhost_work_queue_on(struct vhost_worker *worker,
 	}
 }
 
+static void vhost_work_flush_on(struct vhost_worker *worker)
+{
+	struct vhost_flush_struct flush;
+
+	if (!worker)
+		return;
+
+	init_completion(&flush.wait_event);
+	vhost_work_init(&flush.work, vhost_flush_work);
+
+	vhost_work_queue_on(worker, &flush.work);
+	wait_for_completion(&flush.wait_event);
+}
+
+void vhost_vq_work_flush(struct vhost_virtqueue *vq)
+{
+	vhost_work_flush_on(vq->worker);
+}
+EXPORT_SYMBOL_GPL(vhost_vq_work_flush);
+
 void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work)
 {
 	vhost_work_queue_on(dev->worker, work);
@@ -260,15 +280,7 @@ EXPORT_SYMBOL_GPL(vhost_vq_work_queue);
 
 void vhost_work_dev_flush(struct vhost_dev *dev)
 {
-	struct vhost_flush_struct flush;
-
-	if (dev->worker) {
-		init_completion(&flush.wait_event);
-		vhost_work_init(&flush.work, vhost_flush_work);
-
-		vhost_work_queue(dev, &flush.work);
-		wait_for_completion(&flush.wait_event);
-	}
+	vhost_work_flush_on(dev->worker);
 }
 EXPORT_SYMBOL_GPL(vhost_work_dev_flush);
 
diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index 8f209d1c8890..a985caa35633 100644
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -199,6 +199,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *,
 		      struct vhost_log *log, unsigned int *log_num);
 void vhost_discard_vq_desc(struct vhost_virtqueue *, int n);
 
+void vhost_vq_work_flush(struct vhost_virtqueue *vq);
 void vhost_vq_work_queue(struct vhost_virtqueue *vq, struct vhost_work *work);
 bool vhost_vq_has_work(struct vhost_virtqueue *vq);
 bool vhost_vq_is_setup(struct vhost_virtqueue *vq);
-- 
2.25.1