Hi Zhen, On 2019/4/7 20:41, Zhen Lei wrote: > As Robin Murphy's suggestion: > "It's also not necessarily obvious to the user how this interacts with > IOMMU_DEFAULT_PASSTHROUGH, so if we really do go down this route, maybe it > would be better to refactor the whole lot into a single selection of something > like IOMMU_DEFAULT_MODE anyway." > > In this version, I tried to normalize the IOMMU dma mode boot options for all > ARCHs. When IOMMU is enabled, there are 3 dma modes: paasthrough(bypass), > lazy(mapping but defer the IOTLB invalidation), strict. But currently each > ARCHs defined their private boot options, different with each other. For > example, to enable/disable "passthrough", ARM64 use iommu.passthrough=1/0, > X86 use iommu=pt/nopt, PPC/POWERNV use iommu=nobypass. > > > Zhen Lei (6): > iommu: use iommu.dma_mode to replace iommu.passthrough and > iommu.strict > iommu: keep dma mode build options consistent with cmdline options > iommu: add iommu_default_dma_mode_get() helper > s390/pci: use common boot option iommu.dma_mode > powernv/iommu: use common boot option iommu.dma_mode > x86/iommu: use common boot option iommu.dma_mode This will break systems using boot options as now, and I think this is unacceptable. If you want to do so, just introduce iommu.dma_mode on top of those iommu boot options with dma mode boot options unchanged, and iommu.dma_mode is for all archs but compatible with them. Thanks Hanjun
