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

Miguel Ojeda
2026-02-23T15:31:49Z

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.

Cheers,
Miguel