[PATCH v2 1/1] riscv: Add RVV memset via multiarch/IFUNC

[Yao Zihong]

Hi Vineet,

On Tue, 18 Nov 2025 14:39:01 -0800, Vineet Gupta wrote:
> Discussed this separately with Peter, Jeff and some of the kernel folks here at
> Rivos. It seems the prctl disabled status (at the time of startup, not after the
> fact) can still be honored by doing an additional prctl (PR_RISCV_V_GET_CONTROL)
> is hwprobe says V is present. This will be additional syscall for sure, but in
> the grand scheme of things (syscalls during loader running time), this seems
> negligible.
> IMHO, this can be a followup and need not be tied to this patch and the baseline
> should go in sooner than later.

I agree the extra prctl(PR_RISCV_V_GET_CONTROL) during startup is a negligible cost.
Also looking into what we can do on the hwprobe side. If the kernel folks prefer to
keep IMA_EXT_0 strictly capability-only, then using prctl(PR_RISCV_V_GET_CONTROL)
or adding a new hwprobe key for the policy-filtered V availability could be handled
as a follow-up.

Thanks,
Zihong