netlink: specs: devlink: describe the netns id in the parent-dev nest

devlink_nl_rate_parent_fill() emits DEVLINK_ATTR_PARENT_DEV via
devlink_nl_put_nested_handle(), which adds DEVLINK_ATTR_NETNS_ID
whenever the parent rate node lives on a devlink instance in another
netns. Now that we defined dl-nested-devlink subset, which unlike
dl-parent-dev includes netns-id, let's switch to it. The rate APIs
input genuinely does not accept the netns-id, so we need to subset
them to stick with dl-parent-dev.

Fixes: b5f90fd458 ("devlink: Add parent dev to devlink API")
Link: https://patch.msgid.link/20260915161341.1053476-8-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Documentation/netlink/specs/devlink.yaml

@@ -912,7 +912,7 @@ attribute-sets:
       -
         name: parent-dev
         type: nest
-        nested-attributes: dl-parent-dev
+        nested-attributes: dl-nested-devlink
         doc: |
           Identifies the devlink instance which owns the parent rate node.
           Used with rate-set and rate-new to parent a rate object to a node on
@@ -1390,6 +1390,10 @@ attribute-sets:
   -
     name: dl-parent-dev
     subset-of: devlink
+    doc: |
+      Devlink handle accepted as the parent-dev input; the netns id the
+      kernel reports back is not accepted, the parent is always resolved
+      in the caller's netns.
     attributes:
       -
         name: bus-name
@@ -1398,6 +1402,37 @@ attribute-sets:
       -
         name: index
 
+  -
+    name: dl-rate-set
+    subset-of: devlink
+    doc: Attributes accepted by the rate-set and rate-new requests.
+    attributes:
+      -
+        name: bus-name
+      -
+        name: dev-name
+      -
+        name: index
+      -
+        name: port-index
+      -
+        name: rate-node-name
+      -
+        name: rate-tx-share
+      -
+        name: rate-tx-max
+      -
+        name: rate-tx-priority
+      -
+        name: rate-tx-weight
+      -
+        name: rate-parent-node-name
+      -
+        name: rate-tc-bws
+      -
+        name: parent-dev
+        nested-attributes: dl-parent-dev
+
   -
     name: dl-nested-devlink
     subset-of: devlink
@@ -2387,7 +2422,7 @@ operations:
     -
       name: rate-set
       doc: Set rate instances.
-      attribute-set: devlink
+      attribute-set: dl-rate-set
       dont-validate: [strict]
       flags: [admin-perm]
       do:
@@ -2410,7 +2445,7 @@ operations:
     -
       name: rate-new
       doc: Create rate instances.
-      attribute-set: devlink
+      attribute-set: dl-rate-set
       dont-validate: [strict]
       flags: [admin-perm]
       do: