diff options
| author | Nicolin Chen <nicolinc@nvidia.com> | 2024-10-30 21:20:49 -0300 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2024-11-05 10:24:17 +0000 |
| commit | 6912ec91828b8d7f21b393befad1c36dadbcd751 (patch) | |
| tree | 8b506e00fdbceba7bd036f3068b0d369c4181709 /include/uapi/linux | |
| parent | e89573cf4a13ca4e314d03d56ac84c0ba2af464b (diff) | |
iommu/arm-smmu-v3: Support IOMMU_GET_HW_INFO via struct arm_smmu_hw_info
For virtualization cases the IDR/IIDR/AIDR values of the actual SMMU
instance need to be available to the VMM so it can construct an
appropriate vSMMUv3 that reflects the correct HW capabilities.
For userspace page tables these values are required to constrain the valid
values within the CD table and the IOPTEs.
The kernel does not sanitize these values. If building a VMM then
userspace is required to only forward bits into a VM that it knows it can
implement. Some bits will also require a VMM to detect if appropriate
kernel support is available such as for ATS and BTM.
Start a new file and kconfig for the advanced iommufd support. This lets
it be compiled out for kernels that are not intended to support
virtualization, and allows distros to leave it disabled until they are
shipping a matching qemu too.
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Donald Dutile <ddutile@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5-v4-9e99b76f3518+3a8-smmuv3_nesting_jgg@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/iommufd.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 72010f71c5e4..b5c94fecb94c 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -485,14 +485,49 @@ struct iommu_hw_info_vtd { }; /** + * struct iommu_hw_info_arm_smmuv3 - ARM SMMUv3 hardware information + * (IOMMU_HW_INFO_TYPE_ARM_SMMUV3) + * + * @flags: Must be set to 0 + * @__reserved: Must be 0 + * @idr: Implemented features for ARM SMMU Non-secure programming interface + * @iidr: Information about the implementation and implementer of ARM SMMU, + * and architecture version supported + * @aidr: ARM SMMU architecture version + * + * For the details of @idr, @iidr and @aidr, please refer to the chapters + * from 6.3.1 to 6.3.6 in the SMMUv3 Spec. + * + * User space should read the underlying ARM SMMUv3 hardware information for + * the list of supported features. + * + * Note that these values reflect the raw HW capability, without any insight if + * any required kernel driver support is present. Bits may be set indicating the + * HW has functionality that is lacking kernel software support, such as BTM. If + * a VMM is using this information to construct emulated copies of these + * registers it should only forward bits that it knows it can support. + * + * In future, presence of required kernel support will be indicated in flags. + */ +struct iommu_hw_info_arm_smmuv3 { + __u32 flags; + __u32 __reserved; + __u32 idr[6]; + __u32 iidr; + __u32 aidr; +}; + +/** * enum iommu_hw_info_type - IOMMU Hardware Info Types * @IOMMU_HW_INFO_TYPE_NONE: Used by the drivers that do not report hardware * info * @IOMMU_HW_INFO_TYPE_INTEL_VTD: Intel VT-d iommu info type + * @IOMMU_HW_INFO_TYPE_ARM_SMMUV3: ARM SMMUv3 iommu info type */ enum iommu_hw_info_type { IOMMU_HW_INFO_TYPE_NONE = 0, IOMMU_HW_INFO_TYPE_INTEL_VTD = 1, + IOMMU_HW_INFO_TYPE_ARM_SMMUV3 = 2, }; /** |