BACK_RING_ATTACH
BACK_RING_ATTACH(&ring->blk_rings.native, sring_native,
BACK_RING_ATTACH(&ring->blk_rings.x86_32, sring_x86_32,
BACK_RING_ATTACH(&ring->blk_rings.x86_64, sring_x86_64,
BACK_RING_ATTACH(&vif->ctrl, shared, rsp_prod, XEN_PAGE_SIZE);
BACK_RING_ATTACH(&queue->tx, txs, rsp_prod, XEN_PAGE_SIZE);
BACK_RING_ATTACH(&queue->rx, rxs, rsp_prod, XEN_PAGE_SIZE);
#define BACK_RING_INIT(_r, _s, __size) BACK_RING_ATTACH(_r, _s, 0, __size)