iommufd gives userspace the capability to manipulate iommu subsytem. e.g. DMA map/unmap etc. In the near future, it will support iommu nested translation. Different platform vendors have different implementation for the nested translation. So before set up nested translation, userspace needs to know the hardware iommu information. For example, Intel VT-d supports using guest I/O page table as the stage-1 translation table. This requires guest I/O page table be compatible with hardware IOMMU.
This series reports the iommu hardware information for a given iommufd_device which has been bound to iommufd. It is preparation work for userspace to allocate hwpt for given device. Like the nested translation support[1].
This series introduces an iommu op to report the iommu hardware info, and an ioctl IOMMU_DEVICE_GET_HW_INFO is added to report such hardware info to user. enum iommu_hw_info_type is defined to differentiate the iommu hardware info reported to user hence user can decode them. This series only adds the framework for iommu hw info reporting, the complete reporting path needs vendor specific definition and driver support. The full picture is available in [1] as well.
base-commit: 35db4f4dac813ffaa987cf633694107fabf3aff5
[1] https://github.com/yiliu1765/iommufd/tree/iommufd_nesting
Change log:
v3: - Add r-b from Baolu - Rename IOMMU_HW_INFO_TYPE_DEFAULT to be IOMMU_HW_INFO_TYPE_NONE to better suit what it means - Let IOMMU_DEVICE_GET_HW_INFO succeed even the underlying iommu driver does not have driver-specific data to report per below remark. https://lore.kernel.org/kvm/ZAcwJSK%2F9UVI9LXu@nvidia.com/
v2: https://lore.kernel.org/linux-iommu/20230309075358.571567-1-yi.l.liu@intel.c... - Drop patch 05 of v1 as it is already covered by other series - Rename the capability info to be iommu hardware info
v1: https://lore.kernel.org/linux-iommu/20230209041642.9346-1-yi.l.liu@intel.com...
Regards, Yi Liu
Lu Baolu (1): iommu: Add new iommu op to get iommu hardware information
Nicolin Chen (1): iommufd/selftest: Add coverage for IOMMU_DEVICE_GET_HW_INFO ioctl
Yi Liu (2): iommu: Move dev_iommu_ops() to private header iommufd: Add IOMMU_DEVICE_GET_HW_INFO
drivers/iommu/iommu-priv.h | 11 +++ drivers/iommu/iommu.c | 2 + drivers/iommu/iommufd/device.c | 73 +++++++++++++++++++ drivers/iommu/iommufd/iommufd_private.h | 1 + drivers/iommu/iommufd/iommufd_test.h | 9 +++ drivers/iommu/iommufd/main.c | 3 + drivers/iommu/iommufd/selftest.c | 16 ++++ include/linux/iommu.h | 27 ++++--- include/uapi/linux/iommufd.h | 44 +++++++++++ tools/testing/selftests/iommu/iommufd.c | 17 ++++- tools/testing/selftests/iommu/iommufd_utils.h | 26 +++++++ 11 files changed, 217 insertions(+), 12 deletions(-)