On Mon, Aug 16, 2021 at 10:50:26PM +0800, Tianyu Lan wrote: > Hi Christoph: > Sorry to bother you.Please double check with these two patches > " [PATCH V3 10/13] x86/Swiotlb: Add Swiotlb bounce buffer remap function > for HV IVM" and "[PATCH V3 09/13] DMA: Add dma_map_decrypted/dma_ > unmap_encrypted() function". Do you have a git tree somewhere to look at the whole tree? > The swiotlb bounce buffer in the isolation VM are allocated in the > low end memory and these memory has struct page backing. All dma address > returned by swiotlb/DMA API are low end memory and this is as same as what > happen in the traditional VM. Indeed. > The API dma_map_decrypted() introduced in the patch 9 is to map the > bounce buffer in the extra space and these memory in the low end space are > used as DMA memory in the driver. Do you prefer these APIs > still in the set_memory.c? I move the API to dma/mapping.c due to the > suggested name arch_dma_map_decrypted() in the previous mail > (https://lore.kernel.org/netdev/20210720135437.GA13554@xxxxxx/). Well, what would help is a clear description of the semantics.