Avi Kivity wrote: > Anthony Liguori wrote: > >>> This looks like it wouldn't scale to handle the Sparc systems. There >>> we want to make more translation steps from DVMA addresses to physical >>> in DMA controller and IOMMU and only in the final stage to void *. To >>> handle this, probably there should be an opaque parameter and some way >>> to register the translation function. Otherwise the API looks OK. >>> >>> >> I think having the PCI DMA API translate PhysIOVector => PhysIOVector >> would help. Then it becomes pretty easy to just call the DMA >> controller for additional translation from the IOMMU. >> >> Does that sound right? I don't quite understand what role the opaque >> parameter would serve. >> >> > > State for the dma controller. > > I think Blue is calling for chaining of dma mappings, no? Something > similar is being proposed for the Linux dma api. > >
The way I envision chaining is: virtio-blk calls pci_device_dma_map with a PhysIOVector A pci_device_dma_map calls into PCI IOMMU (if necessary) to translate PhysIOVector A to PhysIOVector B pci_device_dma_map then calls into platform DMA engine to translate PhysIOVector B to PhysIOVector C pci_device_dma_map frees PhysIOVector B and returns PhysIOVector C Regards, Anthony Liguori ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
