virtio: allow transports to get avail/used addresses

For virtio-1, we can theoretically have a more complex virtqueue
layout with avail and used buffers not on a contiguous memory area
with the descriptor table. For now, it's fine for a transport driver
to stay with the old layout: It needs, however, a way to access
the locations of the avail/used rings so it can register them with
the host.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Cornelia Huck 2014-10-07 16:39:47 +02:00 коммит произвёл Michael S. Tsirkin
Родитель 92e6d7438e
Коммит 8906265215
2 изменённых файлов: 19 добавлений и 0 удалений

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@ -827,4 +827,20 @@ void virtio_break_device(struct virtio_device *dev)
}
EXPORT_SYMBOL_GPL(virtio_break_device);
void *virtqueue_get_avail(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->vring.avail;
}
EXPORT_SYMBOL_GPL(virtqueue_get_avail);
void *virtqueue_get_used(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->vring.used;
}
EXPORT_SYMBOL_GPL(virtqueue_get_used);
MODULE_LICENSE("GPL");

Просмотреть файл

@ -75,6 +75,9 @@ unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
bool virtqueue_is_broken(struct virtqueue *vq);
void *virtqueue_get_avail(struct virtqueue *vq);
void *virtqueue_get_used(struct virtqueue *vq);
/**
* virtio_device - representation of a device using virtio
* @index: unique position on the virtio bus