Re: [PATCH v5 23/23] xen/README: add compiler and binutils versions for RISC-V64

[Jan Beulich <jbeulich@xxxxxxxx>]

On 26.02.2024 18:39, Oleksii Kurochko wrote:
> This patch doesn't represent a strict lower bound for GCC and
> GNU Binutils; rather, these versions are specifically employed by
> the Xen RISC-V container and are anticipated to undergo continuous
> testing.

Up and until that container would be updated to a newer gcc. I'm
afraid I view this as too weak a criteria, but I'm also not meaning to
stand in the way if somebody else wants to ack this patch in this form;
my bare minimum requirement is now met.

> --- a/README
> +++ b/README
> @@ -48,6 +48,15 @@ provided by your OS distributor:
>        - For ARM 64-bit:
>          - GCC 5.1 or later
>          - GNU Binutils 2.24 or later
> +      - For RISC-V 64-bit:
> +        - GCC 12.2 or later
> +        - GNU Binutils 2.39 or later
> +        This doesn't represent a strict lower bound for GCC and GNU Binutils;
> +        rather, these versions are specifically employed by the Xen RISC-V
> +        container and are anticipated to undergo continuous testing.

As per above, I think here it really needs saying "at the time of writing"
or recording a concrete date. Furthermore I expect "these versions" relates
to the specifically named versions and particularly _not_ to "or later":
With the criteria you apply, using later versions (or in fact any version
other than the very specific ones used in the container) would be similarly
untested. Much like x86 and Arm don't have the full range of permitted
tool chain versions continuously tested. Plus don't forget that distros may
apply their own selection of patches on top of what they take from upstream
(and they may also take random snapshots rather than released versions).

IOW it is hard for me to see why RISC-V needs stronger restrictions here
than other architectures. It ought to be possible to determine a baseline
version. Even if taking the desire to have "pause" available as a
requirement, gas (and presumably gld) 2.36.1 would already suffice.

Jan