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

[Or Har-Toov <ohartoov@nvidia.com>]

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;
>>   }
>