[PATCH v9 10/32] virtio_ring: split: introduce virtqueue_reinit_split()

[Xuan Zhuo]

Introduce a function to initialize vq without allocating new ring,
desc_state, desc_extra.

Subsequent patches will call this function after reset vq to
reinitialize vq.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 874f878087a3..3dc6ace2ba7a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -953,6 +953,25 @@ static void vring_virtqueue_init_split(struct vring_virtqueue *vq,
 	vq->free_head = 0;
 }
 
+static void virtqueue_reinit_split(struct vring_virtqueue *vq)
+{
+	struct virtio_device *vdev = vq->vq.vdev;
+	int size, i;
+
+	memset(vq->split.vring.desc, 0, vq->split.queue_size_in_bytes);
+
+	size = sizeof(struct vring_desc_state_split) * vq->split.vring.num;
+	memset(vq->split.desc_state, 0, size);
+
+	size = sizeof(struct vring_desc_extra) * vq->split.vring.num;
+	memset(vq->split.desc_extra, 0, size);
+
+	for (i = 0; i < vq->split.vring.num - 1; i++)
+		vq->split.desc_extra[i].next = i + 1;
+
+	vring_virtqueue_init_split(vq, vdev, true);
+}
+
 static void vring_virtqueue_attach_split(struct vring_virtqueue *vq,
 					 struct vring vring,
 					 struct vring_desc_state_split *desc_state,
-- 
2.31.0