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 e5db5325f7eaed..531125f231b662 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3331,21 +3331,6 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
 	return group;
 }
 
-static int arm_smmu_enable_nesting(struct iommu_domain *domain)
-{
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-	int ret = 0;
-
-	mutex_lock(&smmu_domain->init_mutex);
-	if (smmu_domain->smmu)
-		ret = -EPERM;
-	else
-		smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
-	mutex_unlock(&smmu_domain->init_mutex);
-
-	return ret;
-}
-
 static int arm_smmu_of_xlate(struct device *dev,
 			     const struct of_phandle_args *args)
 {
@@ -3467,7 +3452,6 @@ static struct iommu_ops arm_smmu_ops = {
 		.flush_iotlb_all	= arm_smmu_flush_iotlb_all,
 		.iotlb_sync		= arm_smmu_iotlb_sync,
 		.iova_to_phys		= arm_smmu_iova_to_phys,
-		.enable_nesting		= arm_smmu_enable_nesting,
 		.free			= arm_smmu_domain_free_paging,
 	}
 };
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 723273440c2118..38dad1fd53b80a 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -1558,21 +1558,6 @@ static struct iommu_group *arm_smmu_device_group(struct device *dev)
 	return group;
 }
 
-static int arm_smmu_enable_nesting(struct iommu_domain *domain)
-{
-	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
-	int ret = 0;
-
-	mutex_lock(&smmu_domain->init_mutex);
-	if (smmu_domain->smmu)
-		ret = -EPERM;
-	else
-		smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
-	mutex_unlock(&smmu_domain->init_mutex);
-
-	return ret;
-}
-
 static int arm_smmu_set_pgtable_quirks(struct iommu_domain *domain,
 		unsigned long quirks)
 {
@@ -1656,7 +1641,6 @@ static struct iommu_ops arm_smmu_ops = {
 		.flush_iotlb_all	= arm_smmu_flush_iotlb_all,
 		.iotlb_sync		= arm_smmu_iotlb_sync,
 		.iova_to_phys		= arm_smmu_iova_to_phys,
-		.enable_nesting		= arm_smmu_enable_nesting,
 		.set_pgtable_quirks	= arm_smmu_set_pgtable_quirks,
 		.free			= arm_smmu_domain_free,
 	}
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index ed6c5cb60c5aee..9da63d57a53cd7 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2723,16 +2723,6 @@ static int __init iommu_init(void)
 }
 core_initcall(iommu_init);
 
-int iommu_enable_nesting(struct iommu_domain *domain)
-{
-	if (domain->type != IOMMU_DOMAIN_UNMANAGED)
-		return -EINVAL;
-	if (!domain->ops->enable_nesting)
-		return -EINVAL;
-	return domain->ops->enable_nesting(domain);
-}
-EXPORT_SYMBOL_GPL(iommu_enable_nesting);
-
 int iommu_set_pgtable_quirks(struct iommu_domain *domain,
 		unsigned long quirk)
 {
diff --git a/drivers/iommu/iommufd/vfio_compat.c b/drivers/iommu/iommufd/vfio_compat.c
index a3ad5f0b6c59dd..514aacd6400949 100644
--- a/drivers/iommu/iommufd/vfio_compat.c
+++ b/drivers/iommu/iommufd/vfio_compat.c
@@ -291,12 +291,7 @@ static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,
 	case VFIO_DMA_CC_IOMMU:
 		return iommufd_vfio_cc_iommu(ictx);
 
-	/*
-	 * This is obsolete, and to be removed from VFIO. It was an incomplete
-	 * idea that got merged.
-	 * https://lore.kernel.org/kvm/0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com/
-	 */
-	case VFIO_TYPE1_NESTING_IOMMU:
+	case __VFIO_RESERVED_TYPE1_NESTING_IOMMU:
 		return 0;
 
 	/*
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 0960699e75543e..13cf6851cc2718 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -72,7 +72,6 @@ struct vfio_iommu {
 	uint64_t		pgsize_bitmap;
 	uint64_t		num_non_pinned_groups;
 	bool			v2;
-	bool			nesting;
 	bool			dirty_page_tracking;
 	struct list_head	emulated_iommu_groups;
 };
@@ -2199,12 +2198,6 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 		goto out_free_domain;
 	}
 
-	if (iommu->nesting) {
-		ret = iommu_enable_nesting(domain->domain);
-		if (ret)
-			goto out_domain;
-	}
-
 	ret = iommu_attach_group(domain->domain, group->iommu_group);
 	if (ret)
 		goto out_domain;
@@ -2545,9 +2538,7 @@ static void *vfio_iommu_type1_open(unsigned long arg)
 	switch (arg) {
 	case VFIO_TYPE1_IOMMU:
 		break;
-	case VFIO_TYPE1_NESTING_IOMMU:
-		iommu->nesting = true;
-		fallthrough;
+	case __VFIO_RESERVED_TYPE1_NESTING_IOMMU:
 	case VFIO_TYPE1v2_IOMMU:
 		iommu->v2 = true;
 		break;
@@ -2642,7 +2633,6 @@ static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
 	switch (arg) {
 	case VFIO_TYPE1_IOMMU:
 	case VFIO_TYPE1v2_IOMMU:
-	case VFIO_TYPE1_NESTING_IOMMU:
 	case VFIO_UNMAP_ALL:
 		return 1;
 	case VFIO_UPDATE_VADDR:
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4d47f2c3331185..15d7657509f662 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -635,7 +635,6 @@ struct iommu_ops {
  * @enforce_cache_coherency: Prevent any kind of DMA from bypassing IOMMU_CACHE,
  *                           including no-snoop TLPs on PCIe or other platform
  *                           specific mechanisms.
- * @enable_nesting: Enable nesting
  * @set_pgtable_quirks: Set io page table quirks (IO_PGTABLE_QUIRK_*)
  * @free: Release the domain after use.
  */
@@ -663,7 +662,6 @@ struct iommu_domain_ops {
 				    dma_addr_t iova);
 
 	bool (*enforce_cache_coherency)(struct iommu_domain *domain);
-	int (*enable_nesting)(struct iommu_domain *domain);
 	int (*set_pgtable_quirks)(struct iommu_domain *domain,
 				  unsigned long quirks);
 
@@ -846,7 +844,6 @@ extern void iommu_group_put(struct iommu_group *group);
 extern int iommu_group_id(struct iommu_group *group);
 extern struct iommu_domain *iommu_group_default_domain(struct iommu_group *);
 
-int iommu_enable_nesting(struct iommu_domain *domain);
 int iommu_set_pgtable_quirks(struct iommu_domain *domain,
 		unsigned long quirks);
 
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 2b68e6cdf1902f..c8dbf8219c4fcb 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -35,7 +35,7 @@
 #define VFIO_EEH			5
 
 /* Two-stage IOMMU */
-#define VFIO_TYPE1_NESTING_IOMMU	6	/* Implies v2 */
+#define __VFIO_RESERVED_TYPE1_NESTING_IOMMU	6	/* Implies v2 */
 
 #define VFIO_SPAPR_TCE_v2_IOMMU		7
 
