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

[Jason Gunthorpe]

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@xxxxxxxxxx>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> ---
>  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@xxxxxxxxxx>

Jason