[PATCH v7 05/26] virtio_ring: split: extract the logic of init vq and attach vring

Xuan Zhuo
2022-03-08T12:35:45Z

Split the logic of split assignment vq into three parts.

1. The assignment passed from the function parameter
2. The part that attaches vring to vq. -- __vring_virtqueue_attach_split()
3. The part that initializes vq to a fixed value --
__vring_virtqueue_init_split()

This feature is required for subsequent virtuqueue reset vring

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 111 +++++++++++++++++++++--------------
1 file changed, 67 insertions(+), 44 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index d32793615451..dc6313b79305 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2196,34 +2196,40 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
}
EXPORT_SYMBOL_GPL(vring_interrupt);

-/* Only available for split ring */
-struct virtqueue *__vring_new_virtqueue(unsigned int index,
- struct vring vring,
- struct virtio_device *vdev,
- bool weak_barriers,
- bool context,
- bool (*notify)(struct virtqueue *),
- void (*callback)(struct virtqueue *),
- const char *name)
+static int __vring_virtqueue_attach_split(struct vring_virtqueue *vq,
+ struct virtio_device *vdev,
+ struct vring vring)
{
- struct vring_virtqueue *vq;
+ vq->vq.num_free = vring.num;

- if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
- return NULL;
+ vq->split.vring = vring;
+ vq->split.queue_dma_addr = 0;
+ vq->split.queue_size_in_bytes = 0;

- vq = kmalloc(sizeof(*vq), GFP_KERNEL);
- if (!vq)
- return NULL;
+ vq->split.desc_state = kmalloc_array(vring.num,
+ sizeof(struct vring_desc_state_split), GFP_KERNEL);
+ if (!vq->split.desc_state)
+ goto err_state;

+ vq->split.desc_extra = vring_alloc_desc_extra(vq, vring.num);
+ if (!vq->split.desc_extra)
+ goto err_extra;
+
+ memset(vq->split.desc_state, 0, vring.num *
+ sizeof(struct vring_desc_state_split));
+ return 0;
+
+err_extra:
+ kfree(vq->split.desc_state);
+err_state:
+ return -ENOMEM;
+}
+
+static void __vring_virtqueue_init_split(struct vring_virtqueue *vq,
+ struct virtio_device *vdev)
+{
vq->packed_ring = false;
- 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;
- vq->weak_barriers = weak_barriers;
vq->broken = false;
vq->last_used_idx = 0;
vq->event_triggered = false;
@@ -2234,50 +2240,67 @@ struct virtqueue *__vring_new_virtqueue(unsigned int index,
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))
vq->weak_barriers = false;

- vq->split.queue_dma_addr = 0;
- vq->split.queue_size_in_bytes = 0;
-
- vq->split.vring = vring;
vq->split.avail_flags_shadow = 0;
vq->split.avail_idx_shadow = 0;

/* No callback? Tell other side not to bother us. */
- if (!callback) {
+ if (!vq->vq.callback) {
vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
if (!vq->event)
vq->split.vring.avail->flags = cpu_to_virtio16(vdev,
vq->split.avail_flags_shadow);
}

- vq->split.desc_state = kmalloc_array(vring.num,
- sizeof(struct vring_desc_state_split), GFP_KERNEL);
- if (!vq->split.desc_state)
- goto err_state;
-
- vq->split.desc_extra = vring_alloc_desc_extra(vq, vring.num);
- if (!vq->split.desc_extra)
- goto err_extra;
-
/* Put everything in free lists. */
vq->free_head = 0;
- memset(vq->split.desc_state, 0, vring.num *
- sizeof(struct vring_desc_state_split));
+}
+
+/* Only available for split ring */
+struct virtqueue *__vring_new_virtqueue(unsigned int index,
+ struct vring vring,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool context,
+ bool (*notify)(struct virtqueue *),
+ void (*callback)(struct virtqueue *),
+ const char *name)
+{
+ struct vring_virtqueue *vq;
+ int err;
+
+ if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
+ return NULL;
+
+ vq = kmalloc(sizeof(*vq), GFP_KERNEL);
+ if (!vq)
+ return NULL;
+
+ vq->vq.callback = callback;
+ vq->vq.vdev = vdev;
+ vq->vq.name = name;
+ vq->vq.index = index;
+ vq->notify = notify;
+ vq->weak_barriers = weak_barriers;
+ vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
+ !context;
+
+ err = __vring_virtqueue_attach_split(vq, vdev, vring);
+ if (err)
+ goto err;
+
+ __vring_virtqueue_init_split(vq, vdev);

spin_lock(&vdev->vqs_list_lock);
list_add_tail(&vq->vq.list, &vdev->vqs);
spin_unlock(&vdev->vqs_list_lock);
- return &vq->vq;

-err_extra:
- kfree(vq->split.desc_state);
-err_state:
+ return &vq->vq;
+err:
kfree(vq);
return NULL;
}
--
2.31.0