Re: [PATCH V6 2/3] rust: Add PowerPC support

Mukesh Kumar Chaurasiya
2026-03-02T05:55:56Z

On Tue, Feb 24, 2026 at 09:58:10AM +0100, Ralf Jung wrote:
> Hi all,
>
> On 23.02.26 16:31, Miguel Ojeda wrote:
> > On Mon, Feb 23, 2026 at 3:26 AM Mukesh Kumar Chaurasiya
> > <mkchauras@gmail.com> wrote:
> > >
> > > I think, disabling altivec, fpu and vsx with compiler flag will work.
> > >
> > > What are your opinion on this?
> >
> > It is really up to upstream Rust -- for us, i.e. the kernel, it
> > usually doesn't really matter much how things like that are
> > accomplished: whether via flags, a built-in target, a custom target,
> > etc. However, we need to know what the path to stability is.
> >
> > My understanding (but I may be wrong) is that upstream Rust prefer we
> > use built-in targets for softfloat instead of disabling via
> > `-Ctarget-feature` (and that the other options may go away soon and/or
> > will never be stable) -- at least for some cases. For instance, for
> > arm64, please this recent change kernel-side regarding `neon` as an
> > entry point:
> >
> > 446a8351f160 ("arm64: rust: clean Rust 1.85.0 warning using softfloat target")
> >
> > So please ask upstream Rust (probably in their Zulip, e.g. in
> > t-compiler or rust-for-linux channels) what you should do for powerpc.
> > They will likely be happy with a PR adding the target (or whatever
> > they decide) as Alice mentions. And until we reach that minimum
> > version (in a year or more), we can use something else meanwhile. But
> > at least we will have a way towards the end goal, if that makes sense.
> >
> > In case it helps, let me Cc Ralf, Jubilee and Matthew who were
> > involved in some of that discussion in the past, plus the compiler
> > leads.
>
> Upstream Rust dev here. Indeed we'd strongly prefer if this could use a
> built-in Rust target; we can work with you on adding a new target if that is
> needed.
> The kernel currently uses a custom JSON target on x86 and that's quite the
> headache for compiler development: JSON targets are highly unstable and
> directly expose low-level details of how the compiler internally represents
> targets. When we change that representation, we update all built-in targets,
> but of course we cannot update JSON targets. So whenever possible we'd like
> to move towards reducing the number of JSON targets used by the kernel, not
> increase it. :)
>
> Kind regards,
> Ralf
>
Hey,

Sorry for delayed response. I was out of network zone.

I am not sure about the process of how to get this in rust toolchain.
Should I raise an issue of github for this?

Regards,
Mukesh