Re: [PATCH RFCv2 08/13] iommu: Turn iova_cookie to dma-iommu private pointer

From: Jason Gunthorpe
Date: Mon Jan 13 2025 - 11:41:21 EST


On Fri, Jan 10, 2025 at 07:32:24PM -0800, Nicolin Chen wrote:
> Now, iommufd has its own iommufd_sw_msi using iommufd_hwpt, the iommufd
> owned domain's private pointer. Similarly, iova_cookie can be seen as a
> dma-iommu owned domain's private pointer. So, move iova_cookie into the
> union.

This commit message would be clearer as:

Now that iommufd does not rely on dma-iommu.c for any purpose we can
combine the dma-iommu.c iova_cookie and the iommufd_hwpt under the
same union. This union is effectively 'owner data' can be used by the
entity that allocated the domain. Note that legacy vfio type1 flows
continue to use dma-iommu.c for sw_msi and still need iova_cookie.

Jason