Re: [PATCH v2 3/7] iommu: Make iommu_dma_prepare_msi() into a generic operation

On Fri, Feb 21, 2025 at 03:39:45PM +0000, Robin Murphy wrote:

Yuck. Realistically we are going to have no more than two different implementations of this; a fiddly callback interface seems overkill. All we should need in the domain is a simple indicator of *which* MSI translation scheme is in use (if it can't be squeezed into the domain type itself), then iommu_dma_prepare_msi() can simply dispatch between iommu-dma and IOMMUFD based on that, and then it's easy to solve all the other fragility issues too.

That would make module dependency problems, we have so far avoided having the core kernel hard depend on iommufd.

Jason