[PATCH v7 07/26] virtio_ring: packed: extract the logic of init vq and attach vring

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

Split the logic of packed assignment vq into three parts.

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

This feature is required for subsequent virtuqueue reset vring

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
---
drivers/virtio/virtio_ring.c | 138 +++++++++++++++++++++--------------
1 file changed, 82 insertions(+), 56 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1af98b112996..b5a9bf4f45b3 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1773,36 +1773,53 @@ static int vring_create_vring_packed(struct vring_packed *vring,
return -ENOMEM;
}

-static struct virtqueue *vring_create_virtqueue_packed(
- unsigned int index,
- unsigned int num,
- unsigned int vring_align,
- struct virtio_device *vdev,
- bool weak_barriers,
- bool may_reduce_num,
- bool context,
- bool (*notify)(struct virtqueue *),
- void (*callback)(struct virtqueue *),
- const char *name)
+static int vring_virtqueue_attach_packed(struct vring_virtqueue *vq,
+ struct vring_packed *vring,
+ struct virtio_device *vdev)
{
- struct vring_virtqueue *vq;
- struct vring_packed vring;
-
- if (vring_create_vring_packed(&vring, vdev, num))
- goto err_vq;
+ u32 num;

- vq = kmalloc(sizeof(*vq), GFP_KERNEL);
- if (!vq)
- goto err_vq;
+ num = vring->num;

- vq->vq.callback = callback;
- vq->vq.vdev = vdev;
- vq->vq.name = name;
vq->vq.num_free = num;
- vq->vq.index = index;
+
+ vq->packed.ring_dma_addr = vring->ring_dma_addr;
+ vq->packed.driver_event_dma_addr = vring->driver_event_dma_addr;
+ vq->packed.device_event_dma_addr = vring->device_event_dma_addr;
+
+ vq->packed.ring_size_in_bytes = vring->ring_size_in_bytes;
+ vq->packed.event_size_in_bytes = vring->event_size_in_bytes;
+
+ vq->packed.vring.num = num;
+ vq->packed.vring.desc = vring->ring;
+ vq->packed.vring.driver = vring->driver;
+ vq->packed.vring.device = vring->device;
+
+ vq->packed.desc_state = kmalloc_array(num,
+ sizeof(struct vring_desc_state_packed),
+ GFP_KERNEL);
+ if (!vq->packed.desc_state)
+ goto err_desc_state;
+
+ memset(vq->packed.desc_state, 0,
+ num * sizeof(struct vring_desc_state_packed));
+
+ vq->packed.desc_extra = vring_alloc_desc_extra(vq, num);
+ if (!vq->packed.desc_extra)
+ goto err_desc_extra;
+
+ return 0;
+
+err_desc_extra:
+ kfree(vq->packed.desc_state);
+err_desc_state:
+ return -ENOMEM;
+}
+
+static void vring_virtqueue_init_packed(struct vring_virtqueue *vq,
+ struct virtio_device *vdev)
+{
vq->we_own_ring = true;
- vq->notify = notify;
- vq->weak_barriers = weak_barriers;
vq->broken = false;
vq->last_used_idx = 0;
vq->event_triggered = false;
@@ -1814,62 +1831,71 @@ 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))
vq->weak_barriers = false;

- vq->packed.ring_dma_addr = vring.ring_dma_addr;
- vq->packed.driver_event_dma_addr = vring.driver_event_dma_addr;
- vq->packed.device_event_dma_addr = vring.device_event_dma_addr;
-
- vq->packed.ring_size_in_bytes = vring.ring_size_in_bytes;
- vq->packed.event_size_in_bytes = vring.event_size_in_bytes;
-
- vq->packed.vring.num = num;
- vq->packed.vring.desc = vring.ring;
- vq->packed.vring.driver = vring.driver;
- vq->packed.vring.device = vring.device;
-
vq->packed.next_avail_idx = 0;
vq->packed.avail_wrap_counter = 1;
vq->packed.used_wrap_counter = 1;
vq->packed.event_flags_shadow = 0;
vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL;

- vq->packed.desc_state = kmalloc_array(num,
- sizeof(struct vring_desc_state_packed),
- GFP_KERNEL);
- if (!vq->packed.desc_state)
- goto err_desc_state;
-
- memset(vq->packed.desc_state, 0,
- num * sizeof(struct vring_desc_state_packed));
-
/* Put everything in free lists. */
vq->free_head = 0;

- vq->packed.desc_extra = vring_alloc_desc_extra(vq, num);
- if (!vq->packed.desc_extra)
- 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);
}
+}
+
+static struct virtqueue *vring_create_virtqueue_packed(
+ unsigned int index,
+ unsigned int num,
+ unsigned int vring_align,
+ struct virtio_device *vdev,
+ bool weak_barriers,
+ bool may_reduce_num,
+ bool context,
+ bool (*notify)(struct virtqueue *),
+ void (*callback)(struct virtqueue *),
+ const char *name)
+{
+ struct vring_virtqueue *vq;
+ struct vring_packed vring;
+
+ if (vring_create_vring_packed(&vring, vdev, num))
+ goto err_vq;
+
+ vq = kmalloc(sizeof(*vq), GFP_KERNEL);
+ if (!vq)
+ goto err_vq;
+
+ 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;
+
+ if (vring_virtqueue_attach_packed(vq, &vring, vdev))
+ goto err;
+
+ vring_virtqueue_init_packed(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_desc_extra:
- kfree(vq->packed.desc_state);
-err_desc_state:
+err:
kfree(vq);
err_vq:
vring_free_vring_packed(&vring, vdev);
--
2.31.0