1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5a7e874abb36..8484285fbaa8 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3478,3 +3478,106 @@ iommu_attach_handle_get(struct iommu_group *group, ioasid_t pasid, unsigned int
 	return handle;
 }
 EXPORT_SYMBOL_NS_GPL(iommu_attach_handle_get, IOMMUFD_INTERNAL);
+
+/**
+ * iommu_attach_group_handle - Attach an IOMMU domain to an IOMMU group
+ * @domain: IOMMU domain to attach
+ * @group: IOMMU group that will be attached
+ * @handle: attach handle
+ *
+ * Returns 0 on success and error code on failure.
+ *
+ * This is a variant of iommu_attach_group(). It allows the caller to provide
+ * an attach handle and use it when the domain is attached. This is currently
+ * used by IOMMUFD to deliver the I/O page faults.
+ */
+int iommu_attach_group_handle(struct iommu_domain *domain,
+			      struct iommu_group *group,
+			      struct iommu_attach_handle *handle)
+{
+	int ret;
+
+	if (handle)
+		handle->domain = domain;
+
+	mutex_lock(&group->mutex);
+	ret = xa_insert(&group->pasid_array, IOMMU_NO_PASID, handle, GFP_KERNEL);
+	if (ret)
+		goto err_unlock;
+
+	ret = __iommu_attach_group(domain, group);
+	if (ret)
+		goto err_erase;
+	mutex_unlock(&group->mutex);
+
+	return 0;
+err_erase:
+	xa_erase(&group->pasid_array, IOMMU_NO_PASID);
+err_unlock:
+	mutex_unlock(&group->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(iommu_attach_group_handle, IOMMUFD_INTERNAL);
+
+/**
+ * iommu_detach_group_handle - Detach an IOMMU domain from an IOMMU group
+ * @domain: IOMMU domain to attach
+ * @group: IOMMU group that will be attached
+ *
+ * Detach the specified IOMMU domain from the specified IOMMU group.
+ * It must be used in conjunction with iommu_attach_group_handle().
+ */
+void iommu_detach_group_handle(struct iommu_domain *domain,
+			       struct iommu_group *group)
+{
+	mutex_lock(&group->mutex);
+	__iommu_group_set_core_domain(group);
+	xa_erase(&group->pasid_array, IOMMU_NO_PASID);
+	mutex_unlock(&group->mutex);
+}
+EXPORT_SYMBOL_NS_GPL(iommu_detach_group_handle, IOMMUFD_INTERNAL);
+
+/**
+ * iommu_replace_group_handle - replace the domain that a group is attached to
+ * @group: IOMMU group that will be attached to the new domain
+ * @new_domain: new IOMMU domain to replace with
+ * @handle: attach handle
+ *
+ * This is a variant of iommu_group_replace_domain(). It allows the caller to
+ * provide an attach handle for the new domain and use it when the domain is
+ * attached.
+ */
+int iommu_replace_group_handle(struct iommu_group *group,
+			       struct iommu_domain *new_domain,
+			       struct iommu_attach_handle *handle)
+{
+	void *curr;
+	int ret;
+
+	if (!new_domain)
+		return -EINVAL;
+
+	mutex_lock(&group->mutex);
+	if (handle) {
+		ret = xa_reserve(&group->pasid_array, IOMMU_NO_PASID, GFP_KERNEL);
+		if (ret)
+			goto err_unlock;
+	}
+
+	ret = __iommu_group_set_domain(group, new_domain);
+	if (ret)
+		goto err_release;
+
+	curr = xa_store(&group->pasid_array, IOMMU_NO_PASID, handle, GFP_KERNEL);
+	WARN_ON(xa_is_err(curr));
+
+	mutex_unlock(&group->mutex);
+
+	return 0;
+err_release:
+	xa_release(&group->pasid_array, IOMMU_NO_PASID);
+err_unlock:
+	mutex_unlock(&group->mutex);
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(iommu_replace_group_handle, IOMMUFD_INTERNAL);