[PATCH v3 0/4] iommufd: Add iommu hardware info reporting

Yi Liu
2023-05-11T14:31:54Z

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.com/
- 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(-)

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2.34.1