Hey Lu Baolu, thanks for your review! On Thu, Aug 15, 2019 at 01:01:57PM +0800, Lu Baolu wrote: > > +#define IOMMU_CMD_LINE_DMA_API (1 << 0) > > Prefer BIT() micro? Yes, I'll change that. > > + iommu_set_cmd_line_dma_api(); > > IOMMU command line is also set in other places, for example, > iommu_setup() (arch/x86/kernel/pci-dma.c). Need to call this there as > well? You are right, I'll better add a 'bool cmd_line' parameter to the iommu_set_default_*() functions and tell the IOMMU core this way. That will also fix iommu=pt/nopt. Thanks, Joerg