iommu: Add new iommu op to create domains owned by userspace

mainline inclusion
from mainline-v6.7-rc1
commit 909f4abd1097769d024c3a9c2e59c2fbe5d2d0c0
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I8Y6AM
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?909f4abd1097769d024c3a9c2e59c2fbe5d2d0c0

--------------------------------

Introduce a new iommu_domain op to create domains owned by userspace,
e.g. through IOMMUFD. These domains have a few different properties
compares to kernel owned domains:

 - They may be PAGING domains, but created with special parameters.
   For instance aperture size changes/number of levels, different
   IOPTE formats, or other things necessary to make a vIOMMU work

 - We have to track all the memory allocations with GFP_KERNEL_ACCOUNT
   to make the cgroup sandbox stronger

 - Device-specialty domains, such as NESTED domains can be created by
   IOMMUFD.

The new op clearly says the domain is being created by IOMMUFD, that the
domain is intended for userspace use, and it provides a way to pass user
flags or a driver specific uAPI structure to customize the created domain
to exactly what the vIOMMU userspace driver requires.

iommu drivers that cannot support VFIO/IOMMUFD should not support this
op. This includes any driver that cannot provide a fully functional PAGING
domain.

This new op for now is only supposed to be used by IOMMUFD, hence no
wrapper for it. IOMMUFD would call the callback directly. As for domain
free, IOMMUFD would use iommu_domain_free().

Intel-SIG: 909f4abd1097 iommu: Add new iommu op to create domains owned by userspace
Backport IOMMUFD Dirty Tracking

Link: https://lore.kernel.org/r/20230928071528.26258-2-yi.l.liu@intel.com


Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
[ jz: amend commit log ]
Signed-off-by: Jason Zeng <jason.zeng@intel.com>