Re: [RFC PATCH v2 00/45] arm64: Add support for FEAT_NMI

[Vladimir Murzin <vladimir.murzin@arm.com>]

On 8/6/26 18:11, Will Deacon wrote:
> On Mon, 27 Jul 2026 17:34:08 +0100, Vladimir Murzin wrote:
>> FEAT_NMI provides an architected mechanism for supporting non-maskable
>> interrupts (NMIs) and less-masked interrupts (LMIs).
>>
>> Since we already support pseudo-NMIs via priority masking, introducing
>> another flavour of NMI on top of the existing infrastructure could
>> easily become messy, making the code harder to follow and reason
>> about.
>>
>> [...]
> Applied first seven to arm64 (for-next/nmi), thanks!
> 
> [01/45] arm64: ptrace: Remove INIT_PSTATE_EL2
>         https://git.kernel.org/arm64/c/b7f741717d1e
> [02/45] arm64: debug: don't mask DAIF for mdscr_write()
>         https://git.kernel.org/arm64/c/7cf2d6efb86f
> [03/45] arm64: hibernate: mask DAIF before restoring hibernated kernel
>         https://git.kernel.org/arm64/c/684bde100117
> [04/45] arm64: hibernate: Restore DAIF state on error
>         https://git.kernel.org/arm64/c/541549827889
> [05/45] arm64: suspend: rely on daif helpers to handle PMR
>         https://git.kernel.org/arm64/c/630ca6c58fcf
> [06/45] arm64: suspend: Initialize PMR on resume
>         https://git.kernel.org/arm64/c/d3ebdc1772c0
> [07/45] arm64: entry: mask DAIF before returning from C EL1 handlers
>         https://git.kernel.org/arm64/c/0d774e0517f3
> 
> It's a bit of a drop in the ocean, but they seem like sensible
> improvements to me and there's no point in you carrying them out of
> tree.
> 

Thanks a lot!

Vladimir

> Cheers,
> -- Will https://fixes.arm64.dev https://next.arm64.dev https://will.arm64.dev
>