virtio_ring: introduce virtqueue_init()

Separate the logic of virtqueue initialization. These variables should
be reset during reset.

This logic can be called independently when implementing resize/reset
later.

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-Id: <20220801063902.129329-7-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_ring.c

@@ -368,6 +368,24 @@ static int vring_mapping_error(const struct vring_virtqueue *vq,
 	return dma_mapping_error(vring_dma_dev(vq), addr);
 }
 
+static void virtqueue_init(struct vring_virtqueue *vq, u32 num)
+{
+	vq->vq.num_free = num;
+
+	if (vq->packed_ring)
+		vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR);
+	else
+		vq->last_used_idx = 0;
+
+	vq->event_triggered = false;
+	vq->num_added = 0;
+
+#ifdef DEBUG
+	vq->in_use = false;
+	vq->last_add_time_valid = false;
+#endif
+}
+
 
 /*
  * Split ring specific functions - *_split().
@@ -1706,7 +1724,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	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;
 	vq->notify = notify;
@@ -1716,15 +1733,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
 #else
 	vq->broken = false;
 #endif
-	vq->last_used_idx = 0 | (1 << VRING_PACKED_EVENT_F_WRAP_CTR);
-	vq->event_triggered = false;
-	vq->num_added = 0;
 	vq->packed_ring = true;
 	vq->use_dma_api = vring_use_dma_api(vdev);
-#ifdef DEBUG
-	vq->in_use = false;
-	vq->last_add_time_valid = false;
-#endif
 
 	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
 		!context;
@@ -1773,6 +1783,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
 			cpu_to_le16(vq->packed.event_flags_shadow);
 	}
 
+	virtqueue_init(vq, num);
+
 	spin_lock(&vdev->vqs_list_lock);
 	list_add_tail(&vq->vq.list, &vdev->vqs);
 	spin_unlock(&vdev->vqs_list_lock);
@@ -2205,7 +2217,6 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
 	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
 	vq->vq.name = name;
-	vq->vq.num_free = vring.num;
 	vq->vq.index = index;
 	vq->we_own_ring = false;
 	vq->notify = notify;
@@ -2215,14 +2226,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
 #else
 	vq->broken = false;
 #endif
-	vq->last_used_idx = 0;
-	vq->event_triggered = false;
-	vq->num_added = 0;
 	vq->use_dma_api = vring_use_dma_api(vdev);
-#ifdef DEBUG
-	vq->in_use = false;
-	vq->last_add_time_valid = false;
-#endif
 
 	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
 		!context;
@@ -2260,6 +2264,8 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
 	memset(vq->split.desc_state, 0, vring.num *
 			sizeof(struct vring_desc_state_split));
 
+	virtqueue_init(vq, vring.num);
+
 	spin_lock(&vdev->vqs_list_lock);
 	list_add_tail(&vq->vq.list, &vdev->vqs);
 	spin_unlock(&vdev->vqs_list_lock);