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 > > <[email protected]> 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
