Re: [PATCH] rust: support DPDK API

["Van Haaren, Harry" <harry.van.haaren@intel.com>]

> From: Gregory Etelson <getelson@nvidia.com>
> Sent: Thursday, March 6, 2025 1:37 PM
> To: dev@dpdk.org <dev@dpdk.org>
> Cc: getelson@nvidia.com <getelson@nvidia.com>; thomas@monjalon.net <thomas@monjalon.net>; mkashani@nvidia.com <mkashani@nvidia.com>; Richardson, Bruce <bruce.richardson@intel.com>
> Subject: [PATCH] rust: support DPDK API

Cool, I like this subject, great!

> The patch converts include files with DPDK API to RUST and binds new
> RUST API files info dpdklib package.
>
> The RUST dpdklib files and DPDK libraries build from C sources
> allow creation of DPDK application in RUST.
>
> RUST DPDK application must specify the `dpdklib` package as
> dependency in Cargo.toml file.
>
> RUST `dpdklib` package is installed into
> MESON_INSTALL_DESTDIR_PREFIX/rust directory.
>
> Software requirements:
> - clang
> - RUST installation
> - bindgen-cli crate
>
> RUST dpdklib installation instructions:
> 1. Configure DPDK with `-Deanble_rust=true`
> 2. Build and install DPDK. The installation procedure will create
>    MESON_INSTALL_DESTDIR_PREFIX/rust directory.
> 3. Update PKG_CONFIG_PATH to point to DPDK installation.

Interesting approach to automate it; are there specific reasons that this approach was taken,
or did this just seem the easiest/best way to include "Rust support" into upstream DPDK?
Alternatives could be (*not* suggesting to rework the patch!) a dpdk-sys
crate where the bindgen etc is done externally to DPDK itself. Many existing
approaches (some examples: https://youtu.be/lb6xn2xQ-NQ?t=130) use that method.

I kind of like (this approach) of having the binding generation upstream with DPDK itself;
it makes the Rust support upstream and keeps it close to DPDK... however it
means that it is "the one" official/DPDK-community-approved library/crate.

There's some nice tidy-ups to cleanup the namespaces possible if this is "the crate".
Perhaps (sorry, borderline bikeshed-topics..) renames for clarity & readability, e.g.:
dpdklib::rte_eal::rte_eal_init()
   to
dpdk::eal::init()

> Signed-off-by: Gregory Etelson <getelson@nvidia.com>

I'll get to a testing & review in the next days, however I'd like to ask some bigger picture
questions, to understand/provide input on approach, and how big an effor to expect here!
See above linked youtube video - I had sketched out some API concepts for exposing a
"safe Rust API" wrapper around the DPDK C API, which also encodes threading requirements.

Some questions:
- Is there an overaching "we're trying to achieve X with Rust", or specifically "safe Rust"?
- Is this patch the "get DPDK + Rust working", with follow up patches for "safe wrappers" the intention?
- Or is this patch all to expect for now?

Again, thanks for the patch, I think Rust is important for DPDK & infrastructure software,
and will try make time to help test/review/discuss this patch, and the wider Rust effort!

Regards, -Harry

<snip code itself>