On 8/19/2021 4:49 PM, Christoph Hellwig wrote:
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?
Yes, here is my github link for these two patches. https://github.com/lantianyu/linux/commit/462f7e4e44644fe7e182f7a5fb043a75acb90ee5 https://github.com/lantianyu/linux/commit/c8de236bf4366d39e8b98e5a091c39df29b03e0b
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/[email protected]/).Well, what would help is a clear description of the semantics.
Yes, I will improve description.
