On Thu, Mar 24, 2022 at 07:25:03AM +0000, Tian, Kevin wrote: > Based on that here is a quick tweak of the force-snoop part (not compiled). I liked your previous idea better, that IOMMU_CAP_CACHE_COHERENCY started out OK but got weird. So lets fix it back to the way it was. How about this: https://github.com/jgunthorpe/linux/commits/intel_no_snoop b11c19a4b34c2a iommu: Move the Intel no-snoop control off of IOMMU_CACHE 5263947f9d5f36 vfio: Require that device support DMA cache coherence eab4b381c64a30 iommu: Restore IOMMU_CAP_CACHE_COHERENCY to its original meaning 2752e12bed48f6 iommu: Replace uses of IOMMU_CAP_CACHE_COHERENCY with dev_is_dma_coherent() If you like it could you take it from here? Thanks, Jason
