59ddce4418
Except for dart (which forces IOMMU_DOMAIN_DMA) every driver returns 0 or IDENTITY from ops->def_domain_type(). The drivers that return IDENTITY have some kind of good reason, typically that quirky hardware really can't support anything other than IDENTITY. Arrange things so that if the driver says it needs IDENTITY then iommu_get_default_domain_type() either fails or returns IDENTITY. It will not ignore the driver's override to IDENTITY. Split the function into two steps, reducing the group device list to the driver's def_domain_type() and the untrusted flag. Then compute the result based on those two reduced variables. Fully reject combining untrusted with IDENTITY. Remove the debugging print on the iommu_group_store_type() failure path, userspace should not be able to trigger kernel prints. This makes the next patch cleaner that wants to force IDENTITY always for ARM_IOMMU because there is no support for DMA. Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/8-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.