iommufd/selftest: Add coverage for IOMMU_HWPT_ALLOC with nested HWPTs

The IOMMU_HWPT_ALLOC ioctl now supports passing user_data to allocate a
user-managed domain for nested HWPTs. Add its coverage for that. Also,
update _test_cmd_hwpt_alloc() and add test_cmd/err_hwpt_alloc_nested().

Link: https://lore.kernel.org/r/20231026043938.63898-11-yi.l.liu@intel.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>

iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO

Enumerate the capabilities from the mock device and test whether it
advertises as expected. Include it as part of the iommufd_dirty_tracking
fixture.

Link: https://lore.kernel.org/r/20231024135109.73787-18-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Add domain_alloc_user() support in iommu mock

Add mock_domain_alloc_user() and a new test case for
IOMMU_HWPT_ALLOC_NEST_PARENT.

Link: https://lore.kernel.org/r/20230928071528.26258-6-yi.l.liu@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>

iommufd: Fix spelling errors in comments

requres -> requires
dramtically -> dramatically

Link: https://lore.kernel.org/r/31680D47D9533D91+20230904023236.GA12494@xgk8823
Signed-off-by: GuokaiXu <xuguokai@ucas.com.cn>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl

Add a mock_domain_hw_info function and an iommu_test_hw_info data
structure. This allows to test the IOMMU_GET_HW_INFO ioctl passing the
test_reg value for the mock_dev.

Link: https://lore.kernel.org/r/20230818101033.4100-5-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC

Test the basic flow.

Link: https://lore.kernel.org/r/19-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Return the real idev id from selftest mock_domain

Now that we actually call iommufd_device_bind() we can return the
idev_id from that function to userspace for use in other APIs.

Link: https://lore.kernel.org/r/18-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Test iommufd_device_replace()

Allow the selftest to call the function on the mock idev, add some tests
to exercise it.

Link: https://lore.kernel.org/r/16-v8-6659224517ea+532-iommufd_alloc_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Make selftest create a more complete mock device

iommufd wants to use more infrastructure, like the iommu_group, that the
mock device does not support. Create a more complete mock device that can
go through the whole cycle of ownership, blocking domain, and has an
iommu_group.

This requires creating a real struct device on a real bus to be able to
connect it to a iommu_group. Unfortunately we cannot formally attach the
mock iommu driver as an actual driver as the iommu core does not allow
more than one driver or provide a general way for busses to link to
iommus. This can be solved with a little hack to open code the dev_iommus
struct.

With this infrastructure things work exactly the same as the normal domain
path, including the auto domains mechanism and direct attach of hwpts. As
the created hwpt is now an autodomain it is no longer required to destroy
it and trying to do so will trigger a failure.

Link: https://lore.kernel.org/r/11-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd/selftest: Rename the remaining mock device_id's to stdev_id

For consistency.

Link: https://lore.kernel.org/r/10-v3-ae9c2975a131+2e1e8-iommufd_hwpt_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

iommufd: Add a selftest

Cover the essential functionality of the iommufd with a directed test from
userspace. This aims to achieve reasonable functional coverage using the
in-kernel self test framework.

A second test does a failure injection sweep of the success paths to study
error unwind behaviors.

This allows achieving high coverage of the corner cases in pages.c.

The selftest requires CONFIG_IOMMUFD_TEST to be enabled, and several huge
pages which may require:

echo 4 > /proc/sys/vm/nr_hugepages

Link: https://lore.kernel.org/r/19-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Eric Auger <eric.auger@redhat.com> # aarch64
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>