On Wed, Jul 19, 2017 at 4:28 PM, Robin Murphy <robin.murphy@xxxxxxx> wrote: > On 19/07/17 10:33, Anup Patel wrote: >> Some of the IOMMUs (such as ARM SMMU) are capable of bypassing >> transactions for which no IOMMU domain is configured. >> >> This patch adds IOMMU_CAP_BYPASS which can be used by IOMMU >> drivers to advertise transation bypass capability of an IOMMU. > > Whatever the intended semantics of this are, I can't help thinking it > would be better served by allowing callers to explicitly allocate their > own IOMMU_DOMAIN_IDENTITY domains. That would also be useful for the > problem we have with legacy virtio devices behind real IOMMUs. We want to use VFIO no-IOMMU mode for FlexRM device but currently it does not allow on our SOC because IOMMU ops are registered for platform bus. Regards, Anup
