On Mon, 2014-10-06 at 11:59 +0200, Christian Borntraeger wrote: > Just as a comment: On s390 we always considered the memory access as > access to real memory (not device memory) for virtio accesses. I > prefer to not touch the DMA API on s390 as it is quite s390-PCI > specific but it is somewhat strange for CCW devices. > > We would basically have two kinds of DMA mappings on s390 then, one > iommu like for the PCI devices and one that maps DMA memory 1:1 to > real memory. We would also need some buy-in from the s390 arch > maintainers then. It's pretty standard to have the dma API go via dma-ops hanging off struct device, you can then easily make them to the right thing for the type of device... Provided we have a way to identify "bypass everyting" virtio vs. virtio going through normal PCI translation. Cheers, Ben. -- 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
