diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cc07f316adcb18..6cae6e4d693226 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1497,18 +1497,6 @@ static void domain_update_iotlb(struct dmar_domain *domain)
 			break;
 		}
 
-	if (!has_iotlb_device) {
-		struct subdev_domain_info *sinfo;
-
-		list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
-			info = get_domain_info(sinfo->pdev);
-			if (info && info->ats_enabled) {
-				has_iotlb_device = true;
-				break;
-			}
-		}
-	}
-
 	domain->has_iotlb_device = has_iotlb_device;
 }
 
@@ -1606,7 +1594,6 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
 {
 	unsigned long flags;
 	struct device_domain_info *info;
-	struct subdev_domain_info *sinfo;
 
 	if (!domain->has_iotlb_device)
 		return;
@@ -1614,11 +1601,6 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
 	spin_lock_irqsave(&device_domain_lock, flags);
 	list_for_each_entry(info, &domain->devices, link)
 		__iommu_flush_dev_iotlb(info, addr, mask);
-
-	list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
-		info = get_domain_info(sinfo->pdev);
-		__iommu_flush_dev_iotlb(info, addr, mask);
-	}
 	spin_unlock_irqrestore(&device_domain_lock, flags);
 }
 
@@ -1903,7 +1885,6 @@ static struct dmar_domain *alloc_domain(int flags)
 		domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL;
 	domain->has_iotlb_device = false;
 	INIT_LIST_HEAD(&domain->devices);
-	INIT_LIST_HEAD(&domain->subdevices);
 
 	return domain;
 }
@@ -2593,7 +2574,6 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 	info->iommu = iommu;
 	info->pasid_table = NULL;
 	info->auxd_enabled = 0;
-	INIT_LIST_HEAD(&info->subdevices);
 
 	if (dev && dev_is_pci(dev)) {
 		struct pci_dev *pdev = to_pci_dev(info->dev);
@@ -4579,168 +4559,6 @@ is_aux_domain(struct device *dev, struct iommu_domain *domain)
 			domain->type == IOMMU_DOMAIN_UNMANAGED;
 }
 
-static inline struct subdev_domain_info *
-lookup_subdev_info(struct dmar_domain *domain, struct device *dev)
-{
-	struct subdev_domain_info *sinfo;
-
-	if (!list_empty(&domain->subdevices)) {
-		list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
-			if (sinfo->pdev == dev)
-				return sinfo;
-		}
-	}
-
-	return NULL;
-}
-
-static int auxiliary_link_device(struct dmar_domain *domain,
-				 struct device *dev)
-{
-	struct device_domain_info *info = get_domain_info(dev);
-	struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev);
-
-	assert_spin_locked(&device_domain_lock);
-	if (WARN_ON(!info))
-		return -EINVAL;
-
-	if (!sinfo) {
-		sinfo = kzalloc(sizeof(*sinfo), GFP_ATOMIC);
-		sinfo->domain = domain;
-		sinfo->pdev = dev;
-		list_add(&sinfo->link_phys, &info->subdevices);
-		list_add(&sinfo->link_domain, &domain->subdevices);
-	}
-
-	return ++sinfo->users;
-}
-
-static int auxiliary_unlink_device(struct dmar_domain *domain,
-				   struct device *dev)
-{
-	struct device_domain_info *info = get_domain_info(dev);
-	struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev);
-	int ret;
-
-	assert_spin_locked(&device_domain_lock);
-	if (WARN_ON(!info || !sinfo || sinfo->users <= 0))
-		return -EINVAL;
-
-	ret = --sinfo->users;
-	if (!ret) {
-		list_del(&sinfo->link_phys);
-		list_del(&sinfo->link_domain);
-		kfree(sinfo);
-	}
-
-	return ret;
-}
-
-static int aux_domain_add_dev(struct dmar_domain *domain,
-			      struct device *dev)
-{
-	int ret;
-	unsigned long flags;
-	struct intel_iommu *iommu;
-
-	iommu = device_to_iommu(dev, NULL, NULL);
-	if (!iommu)
-		return -ENODEV;
-
-	if (domain->default_pasid <= 0) {
-		u32 pasid;
-
-		/* No private data needed for the default pasid */
-		pasid = ioasid_alloc(NULL, PASID_MIN,
-				     pci_max_pasids(to_pci_dev(dev)) - 1,
-				     NULL);
-		if (pasid == INVALID_IOASID) {
-			pr_err("Can't allocate default pasid\n");
-			return -ENODEV;
-		}
-		domain->default_pasid = pasid;
-	}
-
-	spin_lock_irqsave(&device_domain_lock, flags);
-	ret = auxiliary_link_device(domain, dev);
-	if (ret <= 0)
-		goto link_failed;
-
-	/*
-	 * Subdevices from the same physical device can be attached to the
-	 * same domain. For such cases, only the first subdevice attachment
-	 * needs to go through the full steps in this function. So if ret >
-	 * 1, just goto out.
-	 */
-	if (ret > 1)
-		goto out;
-
-	/*
-	 * iommu->lock must be held to attach domain to iommu and setup the
-	 * pasid entry for second level translation.
-	 */
-	spin_lock(&iommu->lock);
-	ret = domain_attach_iommu(domain, iommu);
-	if (ret)
-		goto attach_failed;
-
-	/* Setup the PASID entry for mediated devices: */
-	if (domain_use_first_level(domain))
-		ret = domain_setup_first_level(iommu, domain, dev,
-					       domain->default_pasid);
-	else
-		ret = intel_pasid_setup_second_level(iommu, domain, dev,
-						     domain->default_pasid);
-	if (ret)
-		goto table_failed;
-
-	spin_unlock(&iommu->lock);
-out:
-	spin_unlock_irqrestore(&device_domain_lock, flags);
-
-	return 0;
-
-table_failed:
-	domain_detach_iommu(domain, iommu);
-attach_failed:
-	spin_unlock(&iommu->lock);
-	auxiliary_unlink_device(domain, dev);
-link_failed:
-	spin_unlock_irqrestore(&device_domain_lock, flags);
-	if (list_empty(&domain->subdevices) && domain->default_pasid > 0)
-		ioasid_put(domain->default_pasid);
-
-	return ret;
-}
-
-static void aux_domain_remove_dev(struct dmar_domain *domain,
-				  struct device *dev)
-{
-	struct device_domain_info *info;
-	struct intel_iommu *iommu;
-	unsigned long flags;
-
-	if (!is_aux_domain(dev, &domain->domain))
-		return;
-
-	spin_lock_irqsave(&device_domain_lock, flags);
-	info = get_domain_info(dev);
-	iommu = info->iommu;
-
-	if (!auxiliary_unlink_device(domain, dev)) {
-		spin_lock(&iommu->lock);
-		intel_pasid_tear_down_entry(iommu, dev,
-					    domain->default_pasid, false);
-		domain_detach_iommu(domain, iommu);
-		spin_unlock(&iommu->lock);
-	}
-
-	spin_unlock_irqrestore(&device_domain_lock, flags);
-
-	if (list_empty(&domain->subdevices) && domain->default_pasid > 0)
-		ioasid_put(domain->default_pasid);
-}
-
 static int prepare_domain_attach_device(struct iommu_domain *domain,
 					struct device *dev)
 {
@@ -4813,33 +4631,12 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
 	return domain_add_dev_info(to_dmar_domain(domain), dev);
 }
 
-static int intel_iommu_aux_attach_device(struct iommu_domain *domain,
-					 struct device *dev)
-{
-	int ret;
-
-	if (!is_aux_domain(dev, domain))
-		return -EPERM;
-
-	ret = prepare_domain_attach_device(domain, dev);
-	if (ret)
-		return ret;
-
-	return aux_domain_add_dev(to_dmar_domain(domain), dev);
-}
-
 static void intel_iommu_detach_device(struct iommu_domain *domain,
 				      struct device *dev)
 {
 	dmar_remove_one_dev_info(dev);
 }
 
-static void intel_iommu_aux_detach_device(struct iommu_domain *domain,
-					  struct device *dev)
-{
-	aux_domain_remove_dev(to_dmar_domain(domain), dev);
-}
-
 #ifdef CONFIG_INTEL_IOMMU_SVM
 /*
  * 2D array for converting and sanitizing IOMMU generic TLB granularity to
@@ -5474,8 +5271,6 @@ const struct iommu_ops intel_iommu_ops = {
 	.enable_nesting		= intel_iommu_enable_nesting,
 	.attach_dev		= intel_iommu_attach_device,
 	.detach_dev		= intel_iommu_detach_device,
-	.aux_attach_dev		= intel_iommu_aux_attach_device,
-	.aux_detach_dev		= intel_iommu_aux_detach_device,
 	.map			= intel_iommu_map,
 	.iotlb_sync_map		= intel_iommu_iotlb_sync_map,
 	.unmap			= intel_iommu_unmap,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6721ac17baf29b..c4b92270946c2f 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2901,39 +2901,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
 }
 EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);
 
-/*
- * Aux-domain specific attach/detach.
- *
- * Only works if iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) returns
- * true. Also, as long as domains are attached to a device through this
- * interface, any tries to call iommu_attach_device() should fail
- * (iommu_detach_device() can't fail, so we fail when trying to re-attach).
- * This should make us safe against a device being attached to a guest as a
- * whole while there are still pasid users on it (aux and sva).
- */
-int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
-{
-	int ret = -ENODEV;
-
-	if (domain->ops->aux_attach_dev)
-		ret = domain->ops->aux_attach_dev(domain, dev);
-
-	if (!ret)
-		trace_attach_device_to_domain(dev);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
-
-void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
-{
-	if (domain->ops->aux_detach_dev) {
-		domain->ops->aux_detach_dev(domain, dev);
-		trace_detach_device_from_domain(dev);
-	}
-}
-EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
-
 /**
  * iommu_sva_bind_device() - Bind a process address space to a device
  * @dev: the device
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 03faf20a6817e8..c12b8e6545733c 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -548,7 +548,6 @@ struct dmar_domain {
 
 	bool has_iotlb_device;
 	struct list_head devices;	/* all devices' list */
-	struct list_head subdevices;	/* all subdevices' list */
 	struct iova_domain iovad;	/* iova's that belong to this domain */
 
 	struct dma_pte	*pgd;		/* virtual address */
@@ -621,15 +620,6 @@ struct intel_iommu {
 	struct dmar_drhd_unit *drhd;
 };
 
-/* Per subdevice private data */
-struct subdev_domain_info {
-	struct list_head link_phys;	/* link to phys device siblings */
-	struct list_head link_domain;	/* link to domain siblings */
-	struct device *pdev;		/* physical device derived from */
-	struct dmar_domain *domain;	/* aux-domain */
-	int users;			/* user count */
-};
-
 /* PCI domain-device relationship */
 struct device_domain_info {
 	struct list_head link;	/* link to domain siblings */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index d8aa5c8a5ba57a..b0bf99dfd80d16 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -258,10 +258,6 @@ struct iommu_ops {
 	int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
 	int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);
 
-	/* Aux-domain specific attach/detach entries */
-	int (*aux_attach_dev)(struct iommu_domain *domain, struct device *dev);
-	void (*aux_detach_dev)(struct iommu_domain *domain, struct device *dev);
-
 	struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
 				      void *drvdata);
 	void (*sva_unbind)(struct iommu_sva *handle);
@@ -590,8 +586,6 @@ void iommu_release_device(struct device *dev);
 int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
 int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f);
 bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f);
-int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev);
-void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev);
 
 struct iommu_sva *iommu_sva_bind_device(struct device *dev,
 					struct mm_struct *mm,
@@ -931,17 +925,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
 	return -ENODEV;
 }
 
-static inline int
-iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
-{
-	return -ENODEV;
-}
-
-static inline void
-iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
-{
-}
-
 static inline struct iommu_sva *
 iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
 {
