Re: [PATCH net-next V4 10/12] devlink: Add resource scope filtering to resource dump

[Or Har-Toov]

On 03/04/2026 5:02, Jakub Kicinski wrote:

On Wed, 1 Apr 2026 21:49:45 +0300 Tariq Toukan wrote:
@@ -873,6 +881,16 @@ attribute-sets:
          doc: Unique devlink instance index.
          checks:
            max: u32-max
+      -
+        name: resource-scope-mask
+        type: bitfield32

no need for a bitfield here, this is a simpler selector
bitfield is for cases when we need to update some persistent
state, in that case we want to indicate which bits we intend
to update:

         cfg = (cfg & ~bf.mask) | bf.val

scope is a straight attribute, there's no updating of anything.

u32 or unit would do

ack, will use u32 for resource scope mask


+        enum: resource-scope
+        enum-as-flags: true
+        doc: |
+          Bitmask selecting which resource classes to include in a
+          resource-dump response. Bit 0 (dev) selects device-level
+          resources; bit 1 (port) selects port-level resources.
+          When absent all classes are returned.
    -
      name: dl-dev-stats
      subset-of: devlink
@@ -1775,7 +1793,11 @@ operations:
              - resource-list
        dump:
          request:
-          attributes: *dev-id-attrs
+          attributes:
+            - bus-name
+            - dev-name
+            - index
+            - resource-scope-mask
          reply: *resource-dump-reply

      -
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 7de2d8cc862f..e0a0b523ce5c 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -645,6 +645,7 @@ enum devlink_attr {
       DEVLINK_ATTR_PARAM_RESET_DEFAULT,       /* flag */

       DEVLINK_ATTR_INDEX,                     /* uint */
+     DEVLINK_ATTR_RESOURCE_SCOPE_MASK,       /* bitfield32 */

       /* Add new attributes above here, update the spec in
        * Documentation/netlink/specs/devlink.yaml and re-generate
@@ -704,6 +705,22 @@ enum devlink_resource_unit {
       DEVLINK_RESOURCE_UNIT_ENTRY,
  };

+enum devlink_resource_scope {
+     DEVLINK_RESOURCE_SCOPE_DEV_BIT,
+     DEVLINK_RESOURCE_SCOPE_PORT_BIT,
+
+     __DEVLINK_RESOURCE_SCOPE_MAX_BIT,
+     DEVLINK_RESOURCE_SCOPE_MAX_BIT =

do we need this? it's not an attr enum all we care about here is
the mask, really so just a trailing value which is max real value + 1
is enough for all users?


ok, can manage without max at all, can manage also without 
DEVLINK_RESOURCE_SCOPE_VALID_MASK

+             __DEVLINK_RESOURCE_SCOPE_MAX_BIT - 1
+};
+
+#define DEVLINK_RESOURCE_SCOPE_DEV \
+     _BITUL(DEVLINK_RESOURCE_SCOPE_DEV_BIT)
+#define DEVLINK_RESOURCE_SCOPE_PORT \
+     _BITUL(DEVLINK_RESOURCE_SCOPE_PORT_BIT)
+#define DEVLINK_RESOURCE_SCOPE_VALID_MASK \
+     (_BITUL(__DEVLINK_RESOURCE_SCOPE_MAX_BIT) - 1)
+
  enum devlink_port_fn_attr_cap {
       DEVLINK_PORT_FN_ATTR_CAP_ROCE_BIT,
       DEVLINK_PORT_FN_ATTR_CAP_MIGRATABLE_BIT,

+static u32 devlink_resource_scope_get(struct nlattr **attrs, int *flags)
+{
+     struct nla_bitfield32 scope;
+     u32 value;
+
+     if (!attrs || !attrs[DEVLINK_ATTR_RESOURCE_SCOPE_MASK])
+             return DEVLINK_RESOURCE_SCOPE_VALID_MASK;
+
+     scope = nla_get_bitfield32(attrs[DEVLINK_ATTR_RESOURCE_SCOPE_MASK]);
+     value = scope.value & scope.selector;
+     if (value != DEVLINK_RESOURCE_SCOPE_VALID_MASK)
+             *flags |= NLM_F_DUMP_FILTERED;
+
+     return value;
+}
+
  static int
  devlink_resource_dump_fill_one(struct sk_buff *skb, struct devlink *devlink,
                              struct devlink_port *devlink_port,
@@ -400,16 +416,27 @@ devlink_nl_resource_dump_one(struct sk_buff *skb, struct 
devlink *devlink,
       struct devlink_nl_dump_state *state = devlink_dump_state(cb);
       struct devlink_port *devlink_port;
       unsigned long port_idx;
+     u32 scope;
       int err;

-     if (!state->port_number) {
+     scope = devlink_resource_scope_get(genl_info_dump(cb)->attrs, &flags);
+     if (!scope) {
+             NL_SET_ERR_MSG_ATTR(genl_info_dump(cb)->extack,
+                                 
genl_info_dump(cb)->attrs[DEVLINK_ATTR_RESOURCE_SCOPE_MASK],

we have genl_info_dump(cb) 3 times here, let's save the pointer
on the stack to make the lines shorter.


ack

+                                 "empty resource scope selection");
+             return -EINVAL;
+     }
+     if (!state->port_number && (scope & DEVLINK_RESOURCE_SCOPE_DEV)) {
               err = devlink_resource_dump_fill_one(skb, devlink, NULL,
-                                                  cb, flags, &state->idx);
+                                                  cb, flags,
+                                                  &state->idx);
               if (err)
                       return err;
               state->idx = 0;
       }

+     if (!(scope & DEVLINK_RESOURCE_SCOPE_PORT))
+             goto out;
       xa_for_each_start(&devlink->ports, port_idx, devlink_port,
                         state->port_number ? state->port_number - 1 : 0) {
               err = devlink_resource_dump_fill_one(skb, devlink, devlink_port,
@@ -420,6 +447,7 @@ devlink_nl_resource_dump_one(struct sk_buff *skb, struct 
devlink *devlink,
               }
               state->idx = 0;
       }
+out:
       state->port_number = 0;
       return 0;
  }