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

Jakub Kicinski
2026-04-03T02:02:22Z

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

> + 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?

> + __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.

> + "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;
> }