[PATCH v4 06/14] virtio_ring: queue_reset: packed: support enable reset queue

[Xuan Zhuo]

The purpose of this patch is to make vring packed support re-enable reset
vq.

Based on whether the incoming vq passed by vring_setup_virtqueue() is
NULL or not, distinguish whether it is a normal create virtqueue or
re-enable a reset queue.

When re-enable a reset queue, reuse the original callback, name, priv,
indirect.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/virtio/virtio_ring.c | 32 +++++++++++++++++++++-----------
 1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 8530f144329b..5a524ee8b542 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1681,7 +1681,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	bool context,
 	bool (*notify)(struct virtqueue *),
 	void (*callback)(struct virtqueue *),
-	const char *name)
+	const char *name,
+	struct virtqueue *_vq)
 {
 	struct vring_virtqueue *vq;
 	struct vring_packed_desc *ring;
@@ -1711,13 +1712,23 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	if (!device)
 		goto err_device;
 
-	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
-	if (!vq)
-		goto err_vq;
+	if (_vq) {
+		vq = to_vvq(_vq);
+	} else {
+		vq = kmalloc(sizeof(*vq), GFP_KERNEL);
+		if (!vq)
+			goto err_vq;
+	}
+
+	if (!_vq) {
+		vq->vq.callback = callback;
+		vq->vq.name = name;
+		vq->vq.priv = NULL;
+		vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
+			!context;
+	}
 
-	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
-	vq->vq.name = name;
 	vq->vq.num_free = num;
 	vq->vq.index = index;
 	vq->we_own_ring = true;
@@ -1734,8 +1745,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	vq->last_add_time_valid = false;
 #endif
 
-	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
-		!context;
 	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
 
 	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
@@ -1776,7 +1785,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 		goto err_desc_extra;
 
 	/* No callback?  Tell other side not to bother us. */
-	if (!callback) {
+	if (!vq->vq.callback) {
 		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
 		vq->packed.vring.driver->flags =
 			cpu_to_le16(vq->packed.event_flags_shadow);
@@ -1790,7 +1799,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
 err_desc_extra:
 	kfree(vq->packed.desc_state);
 err_desc_state:
-	kfree(vq);
+	if (!_vq)
+		kfree(vq);
 err_vq:
 	vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
 err_device:
@@ -2316,7 +2326,7 @@ struct virtqueue *vring_setup_virtqueue(
 	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
 		return vring_create_virtqueue_packed(index, num, vring_align,
 				vdev, weak_barriers, may_reduce_num,
-				context, notify, callback, name);
+				context, notify, callback, name, vq);
 
 	return vring_create_virtqueue_split(index, num, vring_align,
 			vdev, weak_barriers, may_reduce_num,
-- 
2.31.0