Merge branch 'iommu/iommufd/attach-handles' into iommu/next

* iommu/iommufd/attach-handles:
  iommu: Extend domain attach group with handle support
  iommu: Add attach handle to struct iopf_group
  iommu: Remove sva handle list
  iommu: Introduce domain attachment handle

1 files changed, 143 insertions, 42 deletions

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index e15ae1dd494b..aaa6fc8f2705 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -3348,16 +3348,17 @@ static void __iommu_remove_group_pasid(struct iommu_group *group,
  * @domain: the iommu domain.
  * @dev: the attached device.
  * @pasid: the pasid of the device.
+ * @handle: the attach handle.
  *
  * Return: 0 on success, or an error.
  */
 int iommu_attach_device_pasid(struct iommu_domain *domain,
-			      struct device *dev, ioasid_t pasid)
+			      struct device *dev, ioasid_t pasid,
+			      struct iommu_attach_handle *handle)
 {
 	/* Caller must be a probed driver on dev */
 	struct iommu_group *group = dev->iommu_group;
 	struct group_device *device;
-	void *curr;
 	int ret;
 
 	if (!domain->ops->set_dev_pasid)
@@ -3378,11 +3379,12 @@ int iommu_attach_device_pasid(struct iommu_domain *domain,
 		}
 	}
 
-	curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL);
-	if (curr) {
-		ret = xa_err(curr) ? : -EBUSY;
+	if (handle)
+		handle->domain = domain;
+
+	ret = xa_insert(&group->pasid_array, pasid, handle, GFP_KERNEL);
+	if (ret)
 		goto out_unlock;
-	}
 
 	ret = __iommu_set_group_pasid(domain, group, pasid);
 	if (ret)
@@ -3410,46 +3412,11 @@ void iommu_detach_device_pasid(struct iommu_domain *domain, struct device *dev,
 
 	mutex_lock(&group->mutex);
 	__iommu_remove_group_pasid(group, pasid, domain);
-	WARN_ON(xa_erase(&group->pasid_array, pasid) != domain);
+	xa_erase(&group->pasid_array, pasid);
 	mutex_unlock(&group->mutex);
 }
 EXPORT_SYMBOL_GPL(iommu_detach_device_pasid);
 
-/*
- * iommu_get_domain_for_dev_pasid() - Retrieve domain for @pasid of @dev
- * @dev: the queried device
- * @pasid: the pasid of the device
- * @type: matched domain type, 0 for any match
- *
- * This is a variant of iommu_get_domain_for_dev(). It returns the existing
- * domain attached to pasid of a device. Callers must hold a lock around this
- * function, and both iommu_attach/detach_dev_pasid() whenever a domain of
- * type is being manipulated. This API does not internally resolve races with
- * attach/detach.
- *
- * Return: attached domain on success, NULL otherwise.
- */
-struct iommu_domain *iommu_get_domain_for_dev_pasid(struct device *dev,
-						    ioasid_t pasid,
-						    unsigned int type)
-{
-	/* Caller must be a probed driver on dev */
-	struct iommu_group *group = dev->iommu_group;
-	struct iommu_domain *domain;
-
-	if (!group)
-		return NULL;
-
-	xa_lock(&group->pasid_array);
-	domain = xa_load(&group->pasid_array, pasid);
-	if (type && domain && domain->type != type)
-		domain = ERR_PTR(-EBUSY);
-	xa_unlock(&group->pasid_array);
-
-	return domain;
-}
-EXPORT_SYMBOL_GPL(iommu_get_domain_for_dev_pasid);
-
 ioasid_t iommu_alloc_global_pasid(struct device *dev)
 {
 	int ret;
@@ -3476,3 +3443,137 @@ void iommu_free_global_pasid(ioasid_t pasid)
 	ida_free(&iommu_global_pasid_ida, pasid);
 }
 EXPORT_SYMBOL_GPL(iommu_free_global_pasid);
+
+/**
+ * iommu_attach_handle_get - Return the attach handle
+ * @group: the iommu group that domain was attached to
+ * @pasid: the pasid within the group
+ * @type: matched domain type, 0 for any match
+ *
+ * Return handle or ERR_PTR(-ENOENT) on none, ERR_PTR(-EBUSY) on mismatch.
+ *
+ * Return the attach handle to the caller. The life cycle of an iommu attach
+ * handle is from the time when the domain is attached to the time when the
+ * domain is detached. Callers are required to synchronize the call of
+ * iommu_attach_handle_get() with domain attachment and detachment. The attach
+ * handle can only be used during its life cycle.
+ */
+struct iommu_attach_handle *
+iommu_attach_handle_get(struct iommu_group *group, ioasid_t pasid, unsigned int type)
+{
+	struct iommu_attach_handle *handle;
+
+	xa_lock(&group->pasid_array);
+	handle = xa_load(&group->pasid_array, pasid);
+	if (!handle)
+		handle = ERR_PTR(-ENOENT);
+	else if (type && handle->domain->type != type)
+		handle = ERR_PTR(-EBUSY);
+	xa_unlock(&group->pasid_array);
+
+	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);