On Mon, Jan 30, 2023 at 04:57:56PM +0100, Niklas Schnelle wrote: > I'm wondering if maybe instead of plain flag bits it makes more sense > to have a dma_iommu_options struct that contains the queue size and a > flags value which indicates whether a single or per-CPU queue is > used. Querying the driver for what kind of performance tuning it would like to use by default makes sense to me. > Then I could add an iommu_ops callback that takes a device and a > pointer to the dma_iommu_options. That way we can still set the options > per device but don't need a whole extra domain type. This callback > would then just be called during initialization of the DMA-FQ domain > and not having the callback just leaves the defaults unchanged. Does > that go in the right direction? I like it Jason