xen_phys_to_dma
*dma_handle = xen_phys_to_dma(dev, phys);
dev_addr = xen_phys_to_dma(dev, phys);
dev_addr = xen_phys_to_dma(dev, map);
return xen_phys_to_dma(hwdev, default_swiotlb_limit()) <= mask;