On Thu, Jun 26, 2025 at 12:34:50PM -0700, Nicolin Chen wrote:
The hw_info uAPI will support a bidirectional data_type field that can be used as an input field for user space to request for a specific info data.
To prepare for the uAPI update, change the iommu layer first:
- Add a new IOMMU_HW_INFO_TYPE_DEFAULT as an input, for which driver can output its only (or firstly) supported type
- Update the kdoc accordingly
- Roll out the type validation in the existing drivers
Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Reviewed-by: Lu Baolu baolu.lu@linux.intel.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com
include/linux/iommu.h | 3 ++- include/uapi/linux/iommufd.h | 4 +++- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 4 ++++ drivers/iommu/intel/iommu.c | 4 ++++ drivers/iommu/iommufd/device.c | 3 +++ drivers/iommu/iommufd/selftest.c | 4 ++++ 6 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index e06a0fbe4bc7..e8b59ef54e48 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -603,7 +603,8 @@ __iommu_copy_struct_to_user(const struct iommu_user_data *dst_data,
- @capable: check capability
- @hw_info: report iommu hardware information. The data buffer returned by this
op is allocated in the iommu driver and freed by the caller after
use.
use. @type can input a requested type and output a supported type.
Driver should reject an unsupported data @type input- @domain_alloc: Do not use in new drivers
- @domain_alloc_identity: allocate an IDENTITY domain. Drivers should prefer to
use identity_domain instead. This should only be useddiff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index f091ea072c5f..6ad361ff9b06 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -593,13 +593,15 @@ struct iommu_hw_info_arm_smmuv3 { /**
- enum iommu_hw_info_type - IOMMU Hardware Info Types
- @IOMMU_HW_INFO_TYPE_NONE: Used by the drivers that do not report hardware
- @IOMMU_HW_INFO_TYPE_NONE: Output by the drivers that do not report hardware
info*/
- @IOMMU_HW_INFO_TYPE_DEFAULT: Input to request for a default type
- @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_DEFAULT = 0, IOMMU_HW_INFO_TYPE_INTEL_VTD = 1, IOMMU_HW_INFO_TYPE_ARM_SMMUV3 = 2,
}; diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c index 170d69162848..eb9fe1f6311a 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c @@ -15,6 +15,10 @@ void *arm_smmu_hw_info(struct device *dev, u32 *length, u32 __iomem *base_idr; unsigned int i;
- if (*type != IOMMU_HW_INFO_TYPE_DEFAULT &&
*type != IOMMU_HW_INFO_TYPE_ARM_SMMUV3)return ERR_PTR(-EOPNOTSUPP);- info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) return ERR_PTR(-ENOMEM);
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 850f1a6f548c..5f75faffca15 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4098,6 +4098,10 @@ static void *intel_iommu_hw_info(struct device *dev, u32 *length, struct intel_iommu *iommu = info->iommu; struct iommu_hw_info_vtd *vtd;
- if (*type != IOMMU_HW_INFO_TYPE_DEFAULT &&
*type != IOMMU_HW_INFO_TYPE_INTEL_VTD)return ERR_PTR(-EOPNOTSUPP);- vtd = kzalloc(sizeof(*vtd), GFP_KERNEL); if (!vtd) return ERR_PTR(-ENOMEM);
diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c index 8f078fda795a..64a51993e6a1 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -1519,6 +1519,9 @@ int iommufd_get_hw_info(struct iommufd_ucmd *ucmd) cmd->__reserved[2]) return -EOPNOTSUPP;
- /* Clear the type field since drivers don't support a random input */
- cmd->out_data_type = IOMMU_HW_INFO_TYPE_DEFAULT;
- idev = iommufd_get_device(ucmd, cmd->dev_id); if (IS_ERR(idev)) return PTR_ERR(idev);
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index 8b2c44b32530..a5dc36219a90 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -310,6 +310,10 @@ static void *mock_domain_hw_info(struct device *dev, u32 *length, { struct iommu_test_hw_info *info;
- if (*type != IOMMU_HW_INFO_TYPE_DEFAULT &&
*type != IOMMU_HW_INFO_TYPE_SELFTEST)return ERR_PTR(-EOPNOTSUPP);- info = kzalloc(sizeof(*info), GFP_KERNEL); if (!info) return ERR_PTR(-ENOMEM);
Reviewed-by: Pranjal Shrivastava praan@google.com
-- 2.43.0