Hi Andy, On Tue, Oct 27, 2015 at 06:17:09PM -0700, Andy Lutomirski wrote: > From: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > > virtio_ring currently sends the device (usually a hypervisor) > physical addresses of its I/O buffers. This is okay when DMA > addresses and physical addresses are the same thing, but this isn't > always the case. For example, this never works on Xen guests, and > it is likely to fail if a physical "virtio" device ever ends up > behind an IOMMU or swiotlb. The overall code looks good, but I havn't seen and dma_sync* calls. When swiotlb=force is in use this would break. > + vq->vring.desc[head].addr = cpu_to_virtio64(_vq->vdev, vring_map_single( > + vq, > + desc, total_sg * sizeof(struct vring_desc), > + DMA_TO_DEVICE)); Nit: I think readability could be improved here by using a temporary variable for the return value of vring_map_single(). Joerg -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
