virtio: allow transports to get avail/used addresses (89062652) · Commits · 戴 / test

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>

drivers/virtio/virtio_ring.c

+16 −0

Original line number	Diff line number	Diff line
		@@ -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");

include/linux/virtio.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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

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