Re: [PATCH 2/6] arm64/Kconfig: add LSUI Kconfig

From: Marc Zyngier
Date: Wed Jun 11 2025 - 11:22:16 EST


On Wed, 11 Jun 2025 11:49:12 +0100,
Yeoreum Yun <yeoreum.yun@xxxxxxx> wrote:
>
> Since Armv9.6, FEAT_LSUI supplies the load/store instructions for
> previleged level to access to access user memory without clearing
> PSTATE.PAN bit.
> It's enough to add CONFIG_AS_HAS_LSUI only because the code for LUSI uses
> indiviual `.arch_extension` entries.
>
> Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
> ---
> arch/arm64/Kconfig | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 55fc331af337..20f360eef2ac 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -2237,6 +2237,13 @@ config ARM64_GCS
>
> endmenu # "v9.4 architectural features"
>
> +menu "v9.6 architectural features"
> +
> +config AS_HAS_LSUI
> + def_bool $(as-instr,.arch_extension lsui)
> +
> +endmenu # "v9.6 architectural features"
> +
> config ARM64_SVE
> bool "ARM Scalable Vector Extension support"
> default y
> @@ -2498,4 +2505,3 @@ endmenu # "CPU Power Management"
> source "drivers/acpi/Kconfig"
>
> source "arch/arm64/kvm/Kconfig"
> -

Can you please document what toolchain versions have support for this?

Thanks,

M.

--
Without deviation from the norm, progress is not possible.