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.t...@intel.com>
Reviewed-by: Jason Gunthorpe <j...@nvidia.com>
Reviewed-by: Lu Baolu <baolu...@linux.intel.com>
Reviewed-by: Pranjal Shrivastava <pr...@google.com>
Signed-off-by: Nicolin Chen <nicol...@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
used
diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
index 55459b9eee31..fe4b8f9a3403 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 0567faff5680..14955dc43892 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 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);
--
2.43.0
