On 1/19/2023 12:29 PM, Johannes Berg wrote:

On Wed, 2023-01-18 at 16:36 -0800, Jakub Kicinski wrote:

quoted

+kernel-policy
+~~~~~~~~~~~~~
+
+Defines if the kernel validation policy is per operation (``per-op``)
+or for the entire family (``global``). New families should use ``per-op``
+(default) to be able to narrow down the attributes accepted by a specific
+command.

Again I'm not sure I agree with that recommendation, but I know it's
your preference :-)

(IMHO some things become more complex, such as having a "ifindex" in
each one of them)

Per op policy is important because otherwise it can become impossible to
safely extend a new attribute to commands over multiple kernel releases.

If you add an attribute like DEVLINK_ATTR_DRY_RUN in one kernel, and add
it to devlink_cmd_foo.. its no longer really possible to add it to
another command if the policy is global.