From 62622a8753fa6af3c104f9552863e6473b92fb31 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Wed, 9 Jul 2025 22:59:12 -0700 Subject: [PATCH] iommu: Allow an input type in hw_info op 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 Link: https://patch.msgid.link/r/00f4a2d3d930721f61367014717b3ba2d1e82a81.1752126748.git.nicolinc@nvidia.com Reviewed-by: Kevin Tian Reviewed-by: Jason Gunthorpe Reviewed-by: Lu Baolu Reviewed-by: Pranjal Shrivastava Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- 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 ++++ include/linux/iommu.h | 3 ++- include/uapi/linux/iommufd.h | 4 +++- 6 files changed, 20 insertions(+), 2 deletions(-) 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 170d691628487..eb9fe1f6311a0 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 850f1a6f548cc..5f75faffca15a 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 0567faff5680f..14955dc43892d 100644 --- a/drivers/iommu/iommufd/device.c +++ b/drivers/iommu/iommufd/device.c @@ -1512,6 +1512,9 @@ 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 8b2c44b325307..a5dc36219a90c 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); diff --git a/include/linux/iommu.h b/include/linux/iommu.h index e06a0fbe4bc77..e8b59ef54e487 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 used diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index b928c1ed23959..9c8c304b5de22 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, }; -- 2.47.2