Re: [PATCH 01/15] netlink: specs: Introduce multi-message blobs for SPDM

Jakub Kicinski <[email protected]> Tue, 21 Jul 2026 18:20:46 -0700
Newsgroups dev.linux.lists.driver-core,dev.linux.lists.linux-coco,org.kernel.vger.linux-pci
Message-ID <[email protected]>
On Sun,  5 Jul 2026 15:08:05 -0700 Dan Williams wrote:
> The SPDM, Security Protocol and Data Model, underpins PCI device security
> and other use cases. It defines objects that allow for verification of
> device identity and configuration. These objects can be large in size 16MB.
> Netlink is otherwise suitable to define the operations, with optional
> parameters, and notifications for working with these objects. For example,
> operations like "regenerate evidence with nonce", "mark evidence
> validated", and "broadcast evidence / security state change events".
> 
> A netlink 'blob' is introduced as a way to teach YNL that one instance of a
> attribute may span multiple messages. It enables netlink to convey all the
> data needed for verification and manipulation of SPDM transported evidence.
> 
> The schema change to allows YNL to infer that an attribute may span
> multiple messages and interrogate its length to preallocate an
> appropriately sized receive buffer.
> 
> The design direction to extend the netlink schema for a "multi-message
> object receive" case was the result of this discussion [1].

.. continuing the tradition of creative abuse of Netlink.

I don't like this, sorry. You need to come up with something outside
of netlink or more netlink-y.