diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 5ce8e6504ba7..3f691e1fd22c 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2407,9 +2407,8 @@ static struct iommu_domain *amd_iommu_domain_alloc(unsigned int type)
 }
 
 static struct iommu_domain *
-amd_iommu_domain_alloc_user(struct device *dev, u32 flags,
-			    struct iommu_domain *parent,
-			    const struct iommu_user_data *user_data)
+amd_iommu_domain_alloc_paging_flags(struct device *dev, u32 flags,
+				    const struct iommu_user_data *user_data)
 
 {
 	unsigned int type = IOMMU_DOMAIN_UNMANAGED;
@@ -2420,7 +2419,7 @@ amd_iommu_domain_alloc_user(struct device *dev, u32 flags,
 	if (dev)
 		iommu = get_amd_iommu_from_dev(dev);
 
-	if ((flags & ~supported_flags) || parent || user_data)
+	if ((flags & ~supported_flags) || user_data)
 		return ERR_PTR(-EOPNOTSUPP);
 
 	/* Allocate domain with v2 page table if IOMMU supports PASID. */
@@ -2884,7 +2883,7 @@ const struct iommu_ops amd_iommu_ops = {
 	.release_domain = &release_domain,
 	.identity_domain = &identity_domain.domain,
 	.domain_alloc = amd_iommu_domain_alloc,
-	.domain_alloc_user = amd_iommu_domain_alloc_user,
+	.domain_alloc_paging_flags = amd_iommu_domain_alloc_paging_flags,
 	.domain_alloc_sva = amd_iommu_domain_alloc_sva,
 	.probe_device = amd_iommu_probe_device,
 	.release_device = amd_iommu_release_device,
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 04630dbfedd9..e4ebd9e12ad4 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3132,9 +3132,8 @@ static struct iommu_domain arm_smmu_blocked_domain = {
 };
 
 static struct iommu_domain *
-arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
-			   struct iommu_domain *parent,
-			   const struct iommu_user_data *user_data)
+arm_smmu_domain_alloc_paging_flags(struct device *dev, u32 flags,
+				   const struct iommu_user_data *user_data)
 {
 	struct arm_smmu_master *master = dev_iommu_priv_get(dev);
 	const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING |
@@ -3145,7 +3144,7 @@ arm_smmu_domain_alloc_user(struct device *dev, u32 flags,
 
 	if (flags & ~PAGING_FLAGS)
 		return ERR_PTR(-EOPNOTSUPP);
-	if (parent || user_data)
+	if (user_data)
 		return ERR_PTR(-EOPNOTSUPP);
 
 	if (flags & IOMMU_HWPT_ALLOC_PASID)
@@ -3546,7 +3545,7 @@ static struct iommu_ops arm_smmu_ops = {
 	.hw_info		= arm_smmu_hw_info,
 	.domain_alloc_paging    = arm_smmu_domain_alloc_paging,
 	.domain_alloc_sva       = arm_smmu_sva_domain_alloc,
-	.domain_alloc_user	= arm_smmu_domain_alloc_user,
+	.domain_alloc_paging_flags = arm_smmu_domain_alloc_paging_flags,
 	.probe_device		= arm_smmu_probe_device,
 	.release_device		= arm_smmu_release_device,
 	.device_group		= arm_smmu_device_group,
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 6f11a075114f..7d0acb74d5a5 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3328,9 +3328,8 @@ static struct dmar_domain *paging_domain_alloc(struct device *dev, bool first_st
 }
 
 static struct iommu_domain *
-intel_iommu_domain_alloc_user(struct device *dev, u32 flags,
-			      struct iommu_domain *parent,
-			      const struct iommu_user_data *user_data)
+intel_iommu_domain_alloc_paging_flags(struct device *dev, u32 flags,
+				      const struct iommu_user_data *user_data)
 {
 	struct device_domain_info *info = dev_iommu_priv_get(dev);
 	bool dirty_tracking = flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
@@ -3340,9 +3339,6 @@ intel_iommu_domain_alloc_user(struct device *dev, u32 flags,
 	struct iommu_domain *domain;
 	bool first_stage;
 
-	if (parent)
-		return ERR_PTR(-EOPNOTSUPP);
-
 	if (flags &
 	    (~(IOMMU_HWPT_ALLOC_NEST_PARENT | IOMMU_HWPT_ALLOC_DIRTY_TRACKING
 	       | IOMMU_HWPT_FAULT_ID_VALID)))
@@ -4468,7 +4464,7 @@ const struct iommu_ops intel_iommu_ops = {
 	.identity_domain	= &identity_domain,
 	.capable		= intel_iommu_capable,
 	.hw_info		= intel_iommu_hw_info,
-	.domain_alloc_user	= intel_iommu_domain_alloc_user,
+	.domain_alloc_paging_flags = intel_iommu_domain_alloc_paging_flags,
 	.domain_alloc_sva	= intel_svm_domain_alloc,
 	.domain_alloc_paging	= intel_iommu_domain_alloc_paging,
 	.domain_alloc_nested	= intel_iommu_domain_alloc_nested,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7618e9c65d3f..9bc0c74cca3c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1987,8 +1987,8 @@ __iommu_paging_domain_alloc_flags(struct device *dev, unsigned int type,
 
 	if (ops->domain_alloc_paging && !flags)
 		domain = ops->domain_alloc_paging(dev);
-	else if (ops->domain_alloc_user)
-		domain = ops->domain_alloc_user(dev, flags, NULL, NULL);
+	else if (ops->domain_alloc_paging_flags)
+		domain = ops->domain_alloc_paging_flags(dev, flags, NULL);
 	else if (ops->domain_alloc && !flags)
 		domain = ops->domain_alloc(IOMMU_DOMAIN_UNMANAGED);
 	else
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index ec3c64a8c796..ce03c3804651 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -119,7 +119,7 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 
 	lockdep_assert_held(&ioas->mutex);
 
-	if ((flags || user_data) && !ops->domain_alloc_user)
+	if ((flags || user_data) && !ops->domain_alloc_paging_flags)
 		return ERR_PTR(-EOPNOTSUPP);
 	if (flags & ~valid_flags)
 		return ERR_PTR(-EOPNOTSUPP);
@@ -139,9 +139,9 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 	hwpt_paging->ioas = ioas;
 	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
 
-	if (ops->domain_alloc_user) {
-		hwpt->domain = ops->domain_alloc_user(idev->dev, flags, NULL,
-						      user_data);
+	if (ops->domain_alloc_paging_flags) {
+		hwpt->domain = ops->domain_alloc_paging_flags(idev->dev, flags,
+							      user_data);
 		if (IS_ERR(hwpt->domain)) {
 			rc = PTR_ERR(hwpt->domain);
 			hwpt->domain = NULL;
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index c58083c3660a..a0de6d6d4e68 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -379,9 +379,8 @@ mock_domain_alloc_nested(struct device *dev, struct iommu_domain *parent,
 }
 
 static struct iommu_domain *
-mock_domain_alloc_user(struct device *dev, u32 flags,
-		       struct iommu_domain *parent,
-		       const struct iommu_user_data *user_data)
+mock_domain_alloc_paging_flags(struct device *dev, u32 flags,
+			       const struct iommu_user_data *user_data)
 {
 	bool has_dirty_flag = flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
 	const u32 PAGING_FLAGS = IOMMU_HWPT_ALLOC_DIRTY_TRACKING |
@@ -390,9 +389,6 @@ mock_domain_alloc_user(struct device *dev, u32 flags,
 			    MOCK_FLAGS_DEVICE_NO_DIRTY;
 	struct iommu_domain *domain;
 
-	if (parent)
-		return ERR_PTR(-EOPNOTSUPP);
-
 	if (user_data)
 		return ERR_PTR(-EOPNOTSUPP);
 	if ((flags & ~PAGING_FLAGS) || (has_dirty_flag && no_dirty_ops))
@@ -718,7 +714,7 @@ static const struct iommu_ops mock_ops = {
 	.pgsize_bitmap = MOCK_IO_PAGE_SIZE,
 	.hw_info = mock_domain_hw_info,
 	.domain_alloc_paging = mock_domain_alloc_paging,
-	.domain_alloc_user = mock_domain_alloc_user,
+	.domain_alloc_paging_flags = mock_domain_alloc_paging_flags,
 	.domain_alloc_nested = mock_domain_alloc_nested,
 	.capable = mock_domain_capable,
 	.device_group = generic_device_group,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0472cc124519..1e3308e89996 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -557,13 +557,17 @@ iommu_copy_struct_from_full_user_array(void *kdst, size_t kdst_entry_size,
  * @domain_alloc: allocate and return an iommu domain if success. Otherwise
  *                NULL is returned. The domain is not fully initialized until
  *                the caller iommu_domain_alloc() returns.
- * @domain_alloc_user: Allocate an iommu domain corresponding to the input
- *                     parameters as defined in include/uapi/linux/iommufd.h.
- *                     The @user_data can be optionally provided, the
- *                     new domain must support __IOMMU_DOMAIN_PAGING.
- *                     Upon failure, ERR_PTR must be returned.
+ * @domain_alloc_paging_flags: Allocate an iommu domain corresponding to the
+ *                     input parameters as defined in
+ *                     include/uapi/linux/iommufd.h. The @user_data can be
+ *                     optionally provided, the new domain must support
+ *                     __IOMMU_DOMAIN_PAGING. Upon failure, ERR_PTR must be
+ *                     returned.
  * @domain_alloc_paging: Allocate an iommu_domain that can be used for
- *                       UNMANAGED, DMA, and DMA_FQ domain types.
+ *                       UNMANAGED, DMA, and DMA_FQ domain types. This is the
+ *                       same as invoking domain_alloc_paging_flags() with
+ *                       @flags=0, @user_data=NULL. A driver should implement
+ *                       only one of the two ops.
  * @domain_alloc_sva: Allocate an iommu_domain for Shared Virtual Addressing.
  * @domain_alloc_nested: Allocate an iommu_domain for nested translation.
  * @probe_device: Add device to iommu driver handling
@@ -614,8 +618,8 @@ struct iommu_ops {
 
 	/* Domain allocation and freeing by the iommu driver */
 	struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type);
-	struct iommu_domain *(*domain_alloc_user)(
-		struct device *dev, u32 flags, struct iommu_domain *parent,
+	struct iommu_domain *(*domain_alloc_paging_flags)(
+		struct device *dev, u32 flags,
 		const struct iommu_user_data *user_data);
 	struct iommu_domain *(*domain_alloc_paging)(struct device *dev);
 	struct iommu_domain *(*domain_alloc_sva)(struct device *dev,