Re: [PATCH v7 01/10] iommu: Introduce domain attachment handle

Jason Gunthorpe
2024-06-29T01:11:50Z

On Sun, Jun 16, 2024 at 02:11:46PM +0800, Lu Baolu wrote:
> Currently, when attaching a domain to a device or its PASID, domain is
> stored within the iommu group. It could be retrieved for use during the
> window between attachment and detachment.
>
> With new features introduced, there's a need to store more information
> than just a domain pointer. This information essentially represents the
> association between a domain and a device. For example, the SVA code
> already has a custom struct iommu_sva which represents a bond between
> sva domain and a PASID of a device. Looking forward, the IOMMUFD needs
> a place to store the iommufd_device pointer in the core, so that the
> device object ID could be quickly retrieved in the critical fault handling
> path.
>
> Introduce domain attachment handle that explicitly represents the
> attachment relationship between a domain and a device or its PASID.
>
> Co-developed-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
> include/linux/iommu.h | 18 +++++++++++++++---
> drivers/dma/idxd/init.c | 2 +-
> drivers/iommu/iommu-sva.c | 13 ++++++++-----
> drivers/iommu/iommu.c | 26 ++++++++++++++++----------
> 4 files changed, 40 insertions(+), 19 deletions(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason