diff --git a/api-ref/source/os-volume-attachments.inc b/api-ref/source/os-volume-attachments.inc
index 3deb96d05a42..5ca5432b71ed 100644
--- a/api-ref/source/os-volume-attachments.inc
+++ b/api-ref/source/os-volume-attachments.inc
@@ -177,19 +177,25 @@ Update a volume attachment.
 .. note:: This action only valid when the server is in ACTIVE, PAUSED and RESIZED state,
           or a conflict(409) error will be returned.
 
-.. warning:: This API is typically meant to only be used as part of a larger
-             orchestrated volume migration operation initiated in the block
-             storage service via the ``os-retype`` or ``os-migrate_volume``
-             volume actions. Direct usage of this API is not recommended and
-             may result in needing to hard reboot the server to update details
-             within the guest such as block storage serial IDs. Furthermore,
-             this API is only implemented by `certain compute drivers`_.
+.. warning:: When updating volumeId, this API is typically meant to
+             only be used as part of a larger orchestrated volume
+             migration operation initiated in the block storage
+             service via the ``os-retype`` or ``os-migrate_volume``
+             volume actions. Direct usage of this API to update
+             volumeId is not recommended and may result in needing to
+             hard reboot the server to update details within the guest
+             such as block storage serial IDs. Furthermore, updating
+             volumeId via this API is only implemented by `certain
+             compute drivers`_.
 
 .. _certain compute drivers: https://docs.openstack.org/nova/latest/user/support-matrix.html#operation_swap_volume
 
-Policy defaults enable only users with the administrative role to perform
-this operation. Cloud providers can change these permissions through the
-``policy.json`` file.
+Policy default role is 'rule:system_admin_or_owner', its scope is
+[system, project], which allow project members or system admins to
+change the fields of an attached volume of a server. Policy defaults
+enable only users with the administrative role to change ``volumeId``
+via this operation. Cloud providers can change these permissions
+through the ``policy.json`` file.
 
 Updating, or what is commonly referred to as "swapping", volume attachments
 with volumes that have more than one read/write attachment, is not supported.
@@ -207,10 +213,19 @@ Request
   - volume_id: volume_id_swap_src
   - volumeAttachment: volumeAttachment_put
   - volumeId: volumeId_swap
+  - delete_on_termination: delete_on_termination_put_req
+  - device: attachment_device_put_req
+  - serverId: attachment_server_id_put_req
+  - tag: device_tag_bdm_attachment_put_req
+  - id: attachment_id_put_req
 
-**Example Update a volume attachment: JSON request**
+.. note:: Other than ``volumeId``, as of v2.85 only
+          ``delete_on_termination`` may be changed from the current
+          value.
 
-.. literalinclude:: ../../doc/api_samples/os-volumes/update-volume-req.json
+**Example Update a volume attachment (v2.85): JSON request**
+
+.. literalinclude:: ../../doc/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json
    :language: javascript
 
 Response
diff --git a/api-ref/source/parameters.yaml b/api-ref/source/parameters.yaml
index 4dff3fcf2b73..263835d84848 100644
--- a/api-ref/source/parameters.yaml
+++ b/api-ref/source/parameters.yaml
@@ -1776,12 +1776,26 @@ associate_host:
   in: body
   required: true
   type: string
+attachment_device_put_req:
+  description: |
+    Name of the device in the attachment object, such as, ``/dev/vdb``.
+  in: body
+  required: false
+  type: string
+  min_version: 2.85
 attachment_device_resp:
   description: |
     Name of the device in the attachment object, such as, ``/dev/vdb``.
   in: body
   required: false
   type: string
+attachment_id_put_req:
+  description: |
+    The UUID of the attachment.
+  in: body
+  required: false
+  type: string
+  min_version: 2.85
 attachment_id_required:
   description: |
     The UUID of the attachment.
@@ -1794,6 +1808,13 @@ attachment_id_resp:
   in: body
   required: false
   type: string
+attachment_server_id_put_req:
+  description: |
+    The UUID of the server.
+  in: body
+  required: false
+  type: string
+  min_version: 2.85
 attachment_server_id_resp:
   description: |
     The UUID of the server.
@@ -2294,6 +2315,14 @@ delete_on_termination_attachments_resp:
   required: true
   type: boolean
   min_version: 2.79
+delete_on_termination_put_req:
+  description: |
+    A flag indicating if the attached volume will be deleted when the server is
+    deleted.
+  in: body
+  required: false
+  type: boolean
+  min_version: 2.85
 deleted:
   description: |
     A boolean indicates whether this aggregate is deleted or not, if it has
@@ -2384,6 +2413,13 @@ device_tag_bdm_attachment:
   required: false
   type: string
   min_version: 2.49
+device_tag_bdm_attachment_put_req:
+  description: |
+    The device tag applied to the volume block device or ``null``.
+  in: body
+  required: true
+  type: string
+  min_version: 2.85
 device_tag_bdm_attachment_resp:
   description: |
     The device tag applied to the volume block device or ``null``.
@@ -7370,7 +7406,8 @@ volumeAttachment_post:
 volumeAttachment_put:
   description: |
     A dictionary representation of a volume attachment containing the field
-    ``volumeId`` which is the UUID of the replacement volume.
+    ``volumeId`` which is the UUID of the replacement volume, and other fields
+    to update in the attachment.
   in: body
   required: true
   type: object
diff --git a/doc/api_samples/os-volumes/v2.85/attach-volume-to-server-req.json b/doc/api_samples/os-volumes/v2.85/attach-volume-to-server-req.json
new file mode 100644
index 000000000000..b4429e12e968
--- /dev/null
+++ b/doc/api_samples/os-volumes/v2.85/attach-volume-to-server-req.json
@@ -0,0 +1,7 @@
+{
+    "volumeAttachment": {
+        "volumeId": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113",
+        "tag": "foo",
+        "delete_on_termination": true
+    }
+}
\ No newline at end of file
diff --git a/doc/api_samples/os-volumes/v2.85/attach-volume-to-server-resp.json b/doc/api_samples/os-volumes/v2.85/attach-volume-to-server-resp.json
new file mode 100644
index 000000000000..3a60cdc0d095
--- /dev/null
+++ b/doc/api_samples/os-volumes/v2.85/attach-volume-to-server-resp.json
@@ -0,0 +1,10 @@
+{
+    "volumeAttachment": {
+        "delete_on_termination": true,
+        "device": "/dev/sdb",
+        "id": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113",
+        "serverId": "09b3b9d1-b8c5-48e1-841d-62c3ef967a88",
+        "tag": "foo",
+        "volumeId": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113"
+    }
+}
\ No newline at end of file
diff --git a/doc/api_samples/os-volumes/v2.85/list-volume-attachments-resp.json b/doc/api_samples/os-volumes/v2.85/list-volume-attachments-resp.json
new file mode 100644
index 000000000000..ffe7c0baf1eb
--- /dev/null
+++ b/doc/api_samples/os-volumes/v2.85/list-volume-attachments-resp.json
@@ -0,0 +1,20 @@
+{
+    "volumeAttachments": [
+        {
+            "delete_on_termination": false,
+            "device": "/dev/sdc",
+            "id": "227cc671-f30b-4488-96fd-7d0bf13648d8",
+            "serverId": "d5e4ae35-ac0e-4311-a8c5-0ee863e951d9",
+            "tag": null,
+            "volumeId": "227cc671-f30b-4488-96fd-7d0bf13648d8"
+        },
+        {
+            "delete_on_termination": true,
+            "device": "/dev/sdb",
+            "id": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113",
+            "serverId": "d5e4ae35-ac0e-4311-a8c5-0ee863e951d9",
+            "tag": "foo",
+            "volumeId": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/doc/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json b/doc/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json
new file mode 100644
index 000000000000..30105458e7cd
--- /dev/null
+++ b/doc/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json
@@ -0,0 +1,6 @@
+{
+    "volumeAttachment": {
+        "volumeId": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113",
+        "delete_on_termination": true
+    }
+}
diff --git a/doc/api_samples/os-volumes/v2.85/update-volume-req.json b/doc/api_samples/os-volumes/v2.85/update-volume-req.json
new file mode 100644
index 000000000000..e5ad47aa3cce
--- /dev/null
+++ b/doc/api_samples/os-volumes/v2.85/update-volume-req.json
@@ -0,0 +1,5 @@
+{
+    "volumeAttachment": {
+        "volumeId": "227cc671-f30b-4488-96fd-7d0bf13648d8"
+    }
+}
\ No newline at end of file
diff --git a/doc/api_samples/os-volumes/v2.85/volume-attachment-detail-resp.json b/doc/api_samples/os-volumes/v2.85/volume-attachment-detail-resp.json
new file mode 100644
index 000000000000..4a54243c2b1c
--- /dev/null
+++ b/doc/api_samples/os-volumes/v2.85/volume-attachment-detail-resp.json
@@ -0,0 +1,10 @@
+{
+    "volumeAttachment": {
+        "delete_on_termination": true,
+        "device": "/dev/sdb",
+        "id": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113",
+        "serverId": "2aad99d3-7aa4-41e9-b4e6-3f960b115d68",
+        "tag": "foo",
+        "volumeId": "a07f71dc-8151-4e7d-a0cc-cd24a3f11113"
+    }
+}
\ No newline at end of file
diff --git a/doc/api_samples/versions/v21-version-get-resp.json b/doc/api_samples/versions/v21-version-get-resp.json
index 5e5c77561fbc..2d1760aa312f 100644
--- a/doc/api_samples/versions/v21-version-get-resp.json
+++ b/doc/api_samples/versions/v21-version-get-resp.json
@@ -19,7 +19,7 @@
             }
         ],
         "status": "CURRENT",
-        "version": "2.84",
+        "version": "2.85",
         "min_version": "2.1",
         "updated": "2013-07-23T11:33:21Z"
     }
diff --git a/doc/api_samples/versions/versions-get-resp.json b/doc/api_samples/versions/versions-get-resp.json
index 8eb238e31930..d0a29d7ff181 100644
--- a/doc/api_samples/versions/versions-get-resp.json
+++ b/doc/api_samples/versions/versions-get-resp.json
@@ -22,7 +22,7 @@
                 }
             ],
             "status": "CURRENT",
-            "version": "2.84",
+            "version": "2.85",
             "min_version": "2.1",
             "updated": "2013-07-23T11:33:21Z"
         }
diff --git a/nova/api/openstack/api_version_request.py b/nova/api/openstack/api_version_request.py
index 3d2f0549ee88..b6e354e32caf 100644
--- a/nova/api/openstack/api_version_request.py
+++ b/nova/api/openstack/api_version_request.py
@@ -227,6 +227,10 @@ REST_API_VERSION_HISTORY = """REST API Version History:
     * 2.83 - Allow more filter parameters for ``GET /servers/detail`` and
              ``GET /servers`` for non-admin.
     * 2.84 - Adds ``details`` field to instance action events.
+    * 2.85 - Add support for
+             ``PUT /servers/{server_id}/os-volume_attachments/{volume_id}``
+             which supports specifying the ``delete_on_termination`` field in
+             the request body to change the attached volume's flag.
 """
 
 # The minimum and maximum versions of the API supported
@@ -235,7 +239,7 @@ REST_API_VERSION_HISTORY = """REST API Version History:
 # Note(cyeoh): This only applies for the v2.1 API once microversions
 # support is fully merged. It does not affect the V2 API.
 _MIN_API_VERSION = "2.1"
-_MAX_API_VERSION = "2.84"
+_MAX_API_VERSION = "2.85"
 DEFAULT_API_VERSION = _MIN_API_VERSION
 
 # Almost all proxy APIs which are related to network, images and baremetal
diff --git a/nova/api/openstack/compute/rest_api_version_history.rst b/nova/api/openstack/compute/rest_api_version_history.rst
index 28c567e652c2..cb51613d6a6a 100644
--- a/nova/api/openstack/compute/rest_api_version_history.rst
+++ b/nova/api/openstack/compute/rest_api_version_history.rst
@@ -1113,3 +1113,10 @@ The ``GET /servers/{server_id}/os-instance-actions/{request_id}`` API returns
 a ``details`` parameter for each failed event with a fault message, similar to
 the server ``fault.message`` parameter in ``GET /servers/{server_id}`` for a
 server with status ``ERROR``.
+
+2.85
+----
+
+Adds the ability to specify ``delete_on_termination`` in the
+``PUT /servers/{server_id}/os-volume_attachments/{volume_id}`` API, which
+allows changing the behavior of volume deletion on instance deletion.
diff --git a/nova/api/openstack/compute/schemas/volumes.py b/nova/api/openstack/compute/schemas/volumes.py
index 2848f7f2ebb9..6ac52354c1b3 100644
--- a/nova/api/openstack/compute/schemas/volumes.py
+++ b/nova/api/openstack/compute/schemas/volumes.py
@@ -74,7 +74,7 @@ create_volume_attachment = {
                     # NOTE: The validation pattern from match_device() in
                     #       nova/block_device.py.
                     'pattern': '(^/dev/x{0,1}[a-z]{0,1}d{0,1})([a-z]+)[0-9]*$'
-                }
+                },
             },
             'required': ['volumeId'],
             'additionalProperties': False,
@@ -95,6 +95,35 @@ update_volume_attachment = copy.deepcopy(create_volume_attachment)
 del update_volume_attachment['properties']['volumeAttachment'][
     'properties']['device']
 
+# NOTE(brinzhang): Allow attachment_id, serverId, device, tag, and
+# delete_on_termination to be specified for RESTfulness, even though
+# we will not allow updating all of them.
+update_volume_attachment_v285 = {
+    'type': 'object',
+    'properties': {
+        'volumeAttachment': {
+            'type': 'object',
+            'properties': {
+                'volumeId': parameter_types.volume_id,
+                'device': {
+                    'type': ['string', 'null'],
+                    # NOTE: The validation pattern from match_device() in
+                    #       nova/block_device.py.
+                    'pattern': '(^/dev/x{0,1}[a-z]{0,1}d{0,1})([a-z]+)[0-9]*$'
+                },
+                'tag': parameter_types.tag,
+                'delete_on_termination': parameter_types.boolean,
+                'serverId': parameter_types.server_id,
+                'id': parameter_types.attachment_id
+            },
+            'required': ['volumeId'],
+            'additionalProperties': False,
+        },
+    },
+    'required': ['volumeAttachment'],
+    'additionalProperties': False,
+}
+
 index_query = {
     'type': 'object',
     'properties': {
diff --git a/nova/api/openstack/compute/volumes.py b/nova/api/openstack/compute/volumes.py
index 3fa49356a397..6129fa2d5477 100644
--- a/nova/api/openstack/compute/volumes.py
+++ b/nova/api/openstack/compute/volumes.py
@@ -391,15 +391,8 @@ class VolumeAttachmentController(wsgi.Controller):
             attachment['delete_on_termination'] = delete_on_termination
         return {'volumeAttachment': attachment}
 
-    @wsgi.response(202)
-    @wsgi.expected_errors((400, 404, 409))
-    @validation.schema(volumes_schema.update_volume_attachment)
-    def update(self, req, server_id, id, body):
+    def _update_volume_swap(self, req, instance, id, body):
         context = req.environ['nova.context']
-        instance = common.get_instance(self.compute_api, context, server_id)
-        context.can(va_policies.POLICY_ROOT % 'update',
-                    target={'project_id': instance.project_id})
-
         old_volume_id = id
         try:
             old_volume = self.volume_api.get(context, old_volume_id)
@@ -431,7 +424,67 @@ class VolumeAttachmentController(wsgi.Controller):
             raise exc.HTTPConflict(explanation=e.format_message())
         except exception.InstanceInvalidState as state_error:
             common.raise_http_conflict_for_instance_invalid_state(state_error,
-                    'swap_volume', server_id)
+                    'swap_volume', instance.uuid)
+
+    def _update_volume_regular(self, req, instance, id, body):
+        context = req.environ['nova.context']
+        att = body['volumeAttachment']
+        # NOTE(danms): We may be doing an update of regular parameters in
+        # the midst of a swap operation, so to find the original BDM, we need
+        # to use the old volume ID, which is the one in the path.
+        volume_id = id
+
+        try:
+            bdm = objects.BlockDeviceMapping.get_by_volume_and_instance(
+                context, volume_id, instance.uuid)
+
+            # NOTE(danms): The attachment id is just the (current) volume id
+            if 'id' in att and att['id'] != volume_id:
+                raise exc.HTTPBadRequest(explanation='The id property is '
+                                         'not mutable')
+            if 'serverId' in att and att['serverId'] != instance.uuid:
+                raise exc.HTTPBadRequest(explanation='The serverId property '
+                                         'is not mutable')
+            if 'device' in att and att['device'] != bdm.device_name:
+                raise exc.HTTPBadRequest(explanation='The device property is '
+                                         'not mutable')
+            if 'tag' in att and att['tag'] != bdm.tag:
+                raise exc.HTTPBadRequest(explanation='The tag property is '
+                                         'not mutable')
+            if 'delete_on_termination' in att:
+                bdm.delete_on_termination = att['delete_on_termination']
+            bdm.save()
+        except exception.VolumeBDMNotFound as e:
+            raise exc.HTTPNotFound(explanation=e.format_message())
+
+    @wsgi.response(202)
+    @wsgi.expected_errors((400, 404, 409))
+    @validation.schema(volumes_schema.update_volume_attachment, '2.0', '2.84')
+    @validation.schema(volumes_schema.update_volume_attachment_v285,
+                       min_version='2.85')
+    def update(self, req, server_id, id, body):
+        context = req.environ['nova.context']
+        instance = common.get_instance(self.compute_api, context, server_id)
+        # TODO(danms): For now, use the existing admin-only policy for update.
+        # Later, split off the swap_volume permission and check the correct
+        # policy based on what is being asked by the client.
+        context.can(va_policies.POLICY_ROOT % 'update',
+                    target={'project_id': instance.project_id})
+
+        attachment = body['volumeAttachment']
+        volume_id = attachment['volumeId']
+        only_swap = not api_version_request.is_supported(req, '2.85')
+        if only_swap:
+            # NOTE(danms): Original behavior is always call swap on PUT
+            # FIXME(danms): Check the swap volume policy here
+            self._update_volume_swap(req, instance, id, body)
+        else:
+            # NOTE(danms): New behavior is update any supported attachment
+            # properties first, and then call swap if volumeId differs
+            # FIXME(danms): Check the volume attachment update policy here
+            self._update_volume_regular(req, instance, id, body)
+            if id != volume_id:
+                self._update_volume_swap(req, instance, id, body)
 
     @wsgi.response(202)
     @wsgi.expected_errors((400, 403, 404, 409))
diff --git a/nova/api/validation/parameter_types.py b/nova/api/validation/parameter_types.py
index caeb2d7eb055..144a1f64cfe3 100644
--- a/nova/api/validation/parameter_types.py
+++ b/nova/api/validation/parameter_types.py
@@ -336,6 +336,11 @@ volume_id = {
 }
 
 
+attachment_id = {
+    'type': 'string', 'format': 'uuid'
+}
+
+
 volume_type = {
     'type': ['string', 'null'], 'minLength': 0, 'maxLength': 255
 }
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/attach-volume-to-server-req.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/attach-volume-to-server-req.json.tpl
new file mode 100644
index 000000000000..92c13861bb6f
--- /dev/null
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/attach-volume-to-server-req.json.tpl
@@ -0,0 +1,7 @@
+{
+    "volumeAttachment": {
+        "volumeId": "%(volume_id)s",
+        "tag": "%(tag)s",
+        "delete_on_termination": true
+    }
+}
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/attach-volume-to-server-resp.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/attach-volume-to-server-resp.json.tpl
new file mode 100644
index 000000000000..34eacc94d233
--- /dev/null
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/attach-volume-to-server-resp.json.tpl
@@ -0,0 +1,10 @@
+{
+    "volumeAttachment": {
+        "device": "%(device)s",
+        "id": "%(volume_id)s",
+        "serverId": "%(uuid)s",
+        "tag": "%(tag)s",
+        "volumeId": "%(volume_id)s",
+        "delete_on_termination": true
+    }
+}
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/list-volume-attachments-resp.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/list-volume-attachments-resp.json.tpl
new file mode 100644
index 000000000000..700cf5e759f2
--- /dev/null
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/list-volume-attachments-resp.json.tpl
@@ -0,0 +1,20 @@
+{
+    "volumeAttachments": [
+        {
+            "device": "%(device)s",
+            "id": "%(volume_id)s",
+            "serverId": "%(uuid)s",
+            "tag": "%(tag)s",
+            "volumeId": "%(volume_id)s",
+            "delete_on_termination": true
+        },
+        {
+            "device": "%(text)s",
+            "id": "%(volume_id2)s",
+            "serverId": "%(uuid)s",
+            "tag": null,
+            "volumeId": "%(volume_id2)s",
+            "delete_on_termination": false
+        }
+    ]
+}
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json.tpl
new file mode 100644
index 000000000000..2aba36133c5e
--- /dev/null
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/update-volume-attachment-delete-flag-req.json.tpl
@@ -0,0 +1,10 @@
+{
+    "volumeAttachment": {
+        "volumeId": "%(volume_id)s",
+        "id": "%(volume_id)s",
+        "serverId": "%(server_id)s",
+        "device": "%(device)s",
+        "tag": "%(tag)s",
+        "delete_on_termination": true
+    }
+}
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/update-volume-req.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/update-volume-req.json.tpl
new file mode 100644
index 000000000000..85c1244b1438
--- /dev/null
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/update-volume-req.json.tpl
@@ -0,0 +1,5 @@
+{
+    "volumeAttachment": {
+        "volumeId": "%(new_volume_id)s"
+    }
+}
diff --git a/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/volume-attachment-detail-resp.json.tpl b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/volume-attachment-detail-resp.json.tpl
new file mode 100644
index 000000000000..34eacc94d233
--- /dev/null
+++ b/nova/tests/functional/api_sample_tests/api_samples/os-volumes/v2.85/volume-attachment-detail-resp.json.tpl
@@ -0,0 +1,10 @@
+{
+    "volumeAttachment": {
+        "device": "%(device)s",
+        "id": "%(volume_id)s",
+        "serverId": "%(uuid)s",
+        "tag": "%(tag)s",
+        "volumeId": "%(volume_id)s",
+        "delete_on_termination": true
+    }
+}
diff --git a/nova/tests/functional/api_sample_tests/test_volumes.py b/nova/tests/functional/api_sample_tests/test_volumes.py
index 0b5827a0a885..4c48a3e164ee 100644
--- a/nova/tests/functional/api_sample_tests/test_volumes.py
+++ b/nova/tests/functional/api_sample_tests/test_volumes.py
@@ -287,3 +287,33 @@ class VolumeAttachmentsSampleV279(VolumeAttachmentsSampleV270):
     """
     microversion = '2.79'
     scenarios = [('v2_79', {'api_major_version': 'v2.1'})]
+
+
+class UpdateVolumeAttachmentsSampleV285(VolumeAttachmentsSampleV279):
+    """Microversion 2.85 adds the ``PUT
+    /servers/{server_id}/os-volume_attachments/{volume_id}``
+    support for specifying ``delete_on_termination`` field in the request
+    body to re-config the attached volume whether to delete when the instance
+    is deleted.
+    """
+    microversion = '2.85'
+    scenarios = [('v2_85', {'api_major_version': 'v2.1'})]
+
+    def test_volume_attachment_update(self):
+        subs = self.test_attach_volume_to_server()
+        attached_volume_id = subs['volume_id']
+        subs['server_id'] = self.server_id
+        response = self._do_put('servers/%s/os-volume_attachments/%s'
+                                % (self.server_id, attached_volume_id),
+                                'update-volume-attachment-delete-flag-req',
+                                subs)
+        self.assertEqual(202, response.status_code)
+        self.assertEqual('', response.text)
+
+        # Make sure the attached volume was changed
+        attachments = self.api.api_get(
+            '/servers/%s/os-volume_attachments' % self.server_id).body[
+            'volumeAttachments']
+        self.assertEqual(1, len(attachments))
+        self.assertEqual(self.server_id, attachments[0]['serverId'])
+        self.assertTrue(attachments[0]['delete_on_termination'])
diff --git a/nova/tests/unit/api/openstack/compute/test_volumes.py b/nova/tests/unit/api/openstack/compute/test_volumes.py
index c8f5a0beec95..0b04f23f96c5 100644
--- a/nova/tests/unit/api/openstack/compute/test_volumes.py
+++ b/nova/tests/unit/api/openstack/compute/test_volumes.py
@@ -39,6 +39,7 @@ import nova.conf
 from nova import context
 from nova import exception
 from nova import objects
+from nova.objects import block_device as block_device_obj
 from nova import test
 from nova.tests.unit.api.openstack import fakes
 from nova.tests.unit import fake_block_device
@@ -731,8 +732,9 @@ class VolumeAttachTestsV21(test.NoDBTestCase):
                        side_effect=exception.InstanceIsLocked(
                            instance_uuid=uuids.instance))
     def test_swap_volume_for_locked_server(self, mock_swap_volume):
-        self.assertRaises(webob.exc.HTTPConflict, self._test_swap,
-                          self.attachments)
+        with mock.patch.object(self.attachments, '_update_volume_regular'):
+            self.assertRaises(webob.exc.HTTPConflict, self._test_swap,
+                              self.attachments)
         mock_swap_volume.assert_called_once_with(
             self.req.environ['nova.context'], test.MatchType(objects.Instance),
             {'attach_status': 'attached',
@@ -771,8 +773,9 @@ class VolumeAttachTestsV21(test.NoDBTestCase):
         mock_get.side_effect = [
             None, exception.VolumeNotFound(volume_id=FAKE_UUID_C)]
         body = {'volumeAttachment': {'volumeId': FAKE_UUID_C}}
-        self.assertRaises(exc.HTTPBadRequest, self._test_swap,
-                          self.attachments, body=body)
+        with mock.patch.object(self.attachments, '_update_volume_regular'):
+            self.assertRaises(exc.HTTPBadRequest, self._test_swap,
+                              self.attachments, body=body)
         mock_get.assert_has_calls([
             mock.call(self.req.environ['nova.context'], FAKE_UUID_A),
             mock.call(self.req.environ['nova.context'], FAKE_UUID_C)])
@@ -796,17 +799,30 @@ class VolumeAttachTestsV21(test.NoDBTestCase):
     @mock.patch.object(compute_api.API, 'swap_volume',
                        side_effect=exception.VolumeBDMNotFound(
                            volume_id=FAKE_UUID_B))
-    def test_swap_volume_for_bdm_not_found(self, mock_swap_volume):
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance',
+                       side_effect=exception.VolumeBDMNotFound(
+                           volume_id=FAKE_UUID_A))
+    def test_swap_volume_for_bdm_not_found(self, mock_bdm, mock_swap_volume):
         self.assertRaises(webob.exc.HTTPNotFound, self._test_swap,
                           self.attachments)
-        mock_swap_volume.assert_called_once_with(
-            self.req.environ['nova.context'], test.MatchType(objects.Instance),
-            {'attach_status': 'attached',
-             'status': 'in-use',
-             'id': FAKE_UUID_A},
-            {'attach_status': 'detached',
-             'status': 'available',
-             'id': FAKE_UUID_B})
+        if mock_bdm.called:
+            # New path includes regular PUT procedure
+            mock_bdm.assert_called_once_with(self.req.environ['nova.context'],
+                                             FAKE_UUID_A, uuids.instance)
+            mock_swap_volume.assert_not_called()
+        else:
+            # Old path is pure swap-volume
+            mock_bdm.assert_not_called()
+            mock_swap_volume.assert_called_once_with(
+                self.req.environ['nova.context'],
+                test.MatchType(objects.Instance),
+                {'attach_status': 'attached',
+                 'status': 'in-use',
+                 'id': FAKE_UUID_A},
+                {'attach_status': 'detached',
+                 'status': 'available',
+                 'id': FAKE_UUID_B})
 
     def _test_list_with_invalid_filter(self, url):
         req = self._build_request(url)
@@ -1149,6 +1165,296 @@ class VolumeAttachTestsV279(VolumeAttachTestsV2_75):
         self.assertNotIn('delete_on_termination', result['volumeAttachments'])
 
 
+class UpdateVolumeAttachTests(VolumeAttachTestsV279):
+    microversion = '2.85'
+
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    @mock.patch.object(block_device_obj.BlockDeviceMapping, 'save')
+    def test_swap_volume(self, mock_save_bdm, mock_get_bdm):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_bdm.return_value = vol_bdm
+        # On the newer microversion, this test will try to look up the
+        # BDM to check for update of other fields.
+        super(UpdateVolumeAttachTests, self).test_swap_volume()
+
+    def test_swap_volume_with_extra_arg(self):
+        # NOTE(danms): Override this from parent because now device
+        # is checked for unchanged-ness.
+        body = {'volumeAttachment': {'volumeId': FAKE_UUID_A,
+                                     'device': '/dev/fake0',
+                                     'notathing': 'foo'}}
+
+        self.assertRaises(self.validation_error,
+                          self._test_swap,
+                          self.attachments,
+                          body=body)
+
+    @mock.patch.object(compute_api.API, 'swap_volume')
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    @mock.patch.object(block_device_obj.BlockDeviceMapping, 'save')
+    def test_update_volume(self, mock_bdm_save,
+                           mock_get_vol_and_inst, mock_swap):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'tag': 'fake-tag',
+            'delete_on_termination': True,
+            'device': '/dev/fake0',
+        }}
+        self.attachments.update(self.req, FAKE_UUID,
+                                FAKE_UUID_A, body=body)
+        mock_swap.assert_not_called()
+        mock_bdm_save.assert_called_once()
+        self.assertTrue(vol_bdm['delete_on_termination'])
+
+    @mock.patch.object(compute_api.API, 'swap_volume')
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    @mock.patch.object(block_device_obj.BlockDeviceMapping, 'save')
+    def test_update_volume_swap(self, mock_bdm_save,
+                                mock_get_vol_and_inst, mock_swap):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_B,
+            'tag': 'fake-tag',
+            'delete_on_termination': True,
+        }}
+        self.attachments.update(self.req, FAKE_UUID,
+                                FAKE_UUID_A, body=body)
+        mock_bdm_save.assert_called_once()
+        self.assertTrue(vol_bdm['delete_on_termination'])
+        # Swap volume is tested elsewhere, just make sure that we did
+        # attempt to call it in addition to updating the BDM
+        self.assertTrue(mock_swap.called)
+
+    @mock.patch.object(compute_api.API, 'swap_volume')
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    @mock.patch.object(block_device_obj.BlockDeviceMapping, 'save')
+    def test_update_volume_swap_only_old_microversion(
+            self, mock_bdm_save, mock_get_vol_and_inst, mock_swap):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_B,
+        }}
+        req = self._get_req(body, microversion='2.84')
+        self.attachments.update(req, FAKE_UUID,
+                                FAKE_UUID_A, body=body)
+        mock_swap.assert_called_once()
+        mock_bdm_save.assert_not_called()
+
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance',
+                       side_effect=exception.VolumeBDMNotFound(
+                           volume_id=FAKE_UUID_A))
+    def test_update_volume_with_invalid_volume_id(self, mock_mr):
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'delete_on_termination': True,
+        }}
+        self.assertRaises(exc.HTTPNotFound,
+                          self.attachments.update,
+                          self.req, FAKE_UUID,
+                          FAKE_UUID_A, body=body)
+
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    def test_update_volume_with_changed_attachment_id(self,
+                                                      mock_get_vol_and_inst):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'id': uuids.attachment_id2,
+        }}
+        self.assertRaises(exc.HTTPBadRequest,
+                          self.attachments.update,
+                          self.req, FAKE_UUID,
+                          FAKE_UUID_A, body=body)
+
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    def test_update_volume_with_changed_serverId(self,
+                                                 mock_get_vol_and_inst):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'serverId': uuids.server_id,
+        }}
+        self.assertRaises(exc.HTTPBadRequest,
+                          self.attachments.update,
+                          self.req, FAKE_UUID,
+                          FAKE_UUID_A, body=body)
+
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    def test_update_volume_with_changed_device(self, mock_get_vol_and_inst):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'device': '/dev/sdz',
+        }}
+        self.assertRaises(exc.HTTPBadRequest,
+                          self.attachments.update,
+                          self.req, FAKE_UUID,
+                          FAKE_UUID_A, body=body)
+
+    def test_update_volume_with_device_name_old_microversion(self):
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'device': '/dev/fake0',
+        }}
+        req = self._get_req(body, microversion='2.84')
+        ex = self.assertRaises(exception.ValidationError,
+                               self.attachments.update,
+                               req, FAKE_UUID,
+                               FAKE_UUID_A, body=body)
+        self.assertIn('Additional properties are not allowed',
+                      six.text_type(ex))
+
+    @mock.patch.object(objects.BlockDeviceMapping,
+                       'get_by_volume_and_instance')
+    def test_update_volume_with_changed_tag(self, mock_get_vol_and_inst):
+        vol_bdm = objects.BlockDeviceMapping(
+            self.context,
+            id=1,
+            instance_uuid=FAKE_UUID,
+            volume_id=FAKE_UUID_A,
+            source_type='volume',
+            destination_type='volume',
+            delete_on_termination=False,
+            connection_info=None,
+            tag='fake-tag',
+            device_name='/dev/fake0',
+            attachment_id=uuids.attachment_id)
+        mock_get_vol_and_inst.return_value = vol_bdm
+
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+           'tag': 'icanhaznewtag',
+        }}
+        self.assertRaises(exc.HTTPBadRequest,
+                          self.attachments.update,
+                          self.req, FAKE_UUID,
+                          FAKE_UUID_A, body=body)
+
+    def test_update_volume_with_tag_old_microversion(self):
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'tag': 'fake-tag',
+        }}
+        req = self._get_req(body, microversion='2.84')
+        ex = self.assertRaises(exception.ValidationError,
+                               self.attachments.update,
+                               req, FAKE_UUID,
+                               FAKE_UUID_A, body=body)
+        self.assertIn('Additional properties are not allowed',
+                      six.text_type(ex))
+
+    def test_update_volume_with_delete_flag_old_microversion(self):
+        body = {'volumeAttachment': {
+            'volumeId': FAKE_UUID_A,
+            'delete_on_termination': True,
+        }}
+        req = self._get_req(body, microversion='2.84')
+        ex = self.assertRaises(exception.ValidationError,
+                               self.attachments.update,
+                               req, FAKE_UUID,
+                               FAKE_UUID_A, body=body)
+        self.assertIn('Additional properties are not allowed',
+                      six.text_type(ex))
+
+
 class SwapVolumeMultiattachTestCase(test.NoDBTestCase):
 
     @mock.patch('nova.api.openstack.common.get_instance')
diff --git a/releasenotes/notes/bp-destroy-instance-with-datavolume-4c71b12e005832b0.yaml b/releasenotes/notes/bp-destroy-instance-with-datavolume-4c71b12e005832b0.yaml
new file mode 100644
index 000000000000..8abb0210d236
--- /dev/null
+++ b/releasenotes/notes/bp-destroy-instance-with-datavolume-4c71b12e005832b0.yaml
@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    With microversion 2.85 add new API
+    ``PUT /servers/{server_id}/os-volume_attachments/{volume_id}`` which
+    support for specifying ``delete_on_termination`` field in the request
+    body to re-config the attached volume whether to delete when the instance
+    is deleted.