Re: [PATCH] doc: announce marking device and driver objects as internal

[Thomas Monjalon <thomas@monjalon.net>]

11/07/2022 04:16, Xia, Chenbo:
> From: David Marchand <david.marchand@redhat.com>
> > rte_driver and rte_device are unnecessarily exposed in the public API/ABI.
> > Announce that they will be made opaque in the public API and mark
> > associated API as internal.
> > This impacts all bus, as their driver registration mechanism will be
> > made internal.
> > 
> > Note: the PCI bus had a similar deprecation notice that we can remove as
> > the new one is more generic.
[...]
> > --- a/doc/guides/rel_notes/deprecation.rst
> > +++ b/doc/guides/rel_notes/deprecation.rst
> > +* drivers: As a followup on the work on the ``rte_bus`` object, the
> > +  ``rte_driver`` and ``rte_device`` objects (and as a domino effect,
> > their
> > +  bus-specific counterparts) will be made opaque in DPDK 22.11.
> > +  Registering a driver on a bus will be marked as an internal API:
> > +  external users may still register their drivers using the bus specific
> > +  driver header (see ``enable_driver_sdk`` meson option).
> > +
> 
> Cc SPDK folks
> 
> Thanks for your work! My only concern is using enable_driver_sdk may not be
> a good way for SPDK based on the discussion.
> http://patchwork.dpdk.org/project/dpdk/cover/20210918022443.12719-1-chenbo.xia@intel.com/

Quick summary:
- Symbols exported by DPDK by default are supposed to be for applications.
- Option enable_driver_sdk allow installing headers to build drivers.
- Driver interface is not part of the stable ABI, i.e. no compat guarantee.
- SPDK is building drivers on top of DPDK bus drivers (PCI for now).
- SPDK was asked to check whether anything else is required.

There is no decision about ABI guarantee because we lack feedbacks.
After this cleanup, the option enable_driver_sdk would be required
when working with buses, like SPDK.
Is there a real need to build against distro-provided package?
Is there a way to provide bus drivers SDK without messing with app SDK?


> But overall this idea makes sense, so:
> 
> Acked-by: Chenbo Xia <chenbo.xia@intel.com>

I like the cleanup as well. It will allow more enhancements in future.
I hope and believe we can accomodate SDK needs when it will be clear.

Acked-by: Thomas Monjalon <thomas@monjalon.net>