CI pass-through is that the guest's idea of PFN's is not the real thing. To fix that, there is translation layer for PFN->machine frame number and vice-versa. To bubble that up to the SWIOTLB layer there are two possible solutions. One solution has been to wholesale copy the SWIOTLB, stick it in arch/x86/xen/swiotlb.c and modify the virt_to_phys, phys_to_virt and others to use the Xen address translation functions. Unfortunately, since the kernel can run on bare-metal, there would be big code overlap with the real SWIOTLB. (git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git xen/dom0/swiotlb-new) Another approach, which this set of patches explores, is to abstract the address translation and address determination functions away from the SWIOTLB book-keeping functions. This way the core SWIOTLB library functions are present in one place, while the address related functions are in a separate library that can be loaded when running under non-bare-metal platform. Changelog: Since the last posting [v8.2] Konrad has done: - Added this changelog in the patch and referenced in the other patches this description. - 'enum dma_data_direction direction' to 'enum dma.. dir' so to be unified. [v8-v8.2 changes:] - Rolled-up the last two patches in one. - Rebased against linus latest. That meant dealing with swiotlb_sync_single_range_* changes. - added Acked-by: Fujita Tomonori and Tested-by: Albert Herranz [v7-v8 changes:] - Minimized the list of exported functions. - Integrated Fujita's patches and changed "swiotlb_tlb" to "swiotlb_tbl" in them. [v6-v7 changes:] - Minimized the amount of exported functions/variable with a prefix of: "swiotbl_tbl". - Made the usage of 'int dir' to be 'enum dma_data_direction'. [v5-v6 changes:] - Made the exported functions/variables have the 'swiotlb_bk' prefix. - dropped the checkpatches/other reworks Signed-off-by: FUJITA Tomonori Reviewed-by: Konrad Rzeszutek Wilk Tested-by: Albert Herranz _