Re: [PATCH v6 3/9] x86/nmi: Extend the registration interface to include the NMI-source vector

[Xin Li]

On 5/13/2025 1:37 PM, Sohil Mehta wrote:
> To prepare for NMI-source reporting, add a source vector argument to the
> NMI handler registration interface. Later, this will be used to
> register NMI handlers with a unique source vector that can be used to
> identify the originator of the NMI.
>
> For now, just extend the interface and pass zero as the source vector
> for all handlers. No functional change intended.
>
> Originally-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
> Signed-off-by: Sohil Mehta <sohil.mehta@xxxxxxxxx>

Just two nits below, other than that:

Reviewed-by: Xin Li (Intel) <xin@xxxxxxxxx>
> diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
> index 79d88d12c8fb..f0a577bf7bba 100644
> --- a/arch/x86/include/asm/nmi.h
> +++ b/arch/x86/include/asm/nmi.h
> @@ -54,6 +54,7 @@ struct nmiaction {
>   	u64			max_duration;
>   	unsigned long		flags;
>   	const char		*name;
> +	u8			source_vector;
>   };
>   
>   /**
> @@ -62,6 +63,7 @@ struct nmiaction {
>    * @fn:   The NMI handler
>    * @fg:   Flags associated with the NMI handler
>    * @n:    Name of the NMI handler
> + * @src:  NMI-source based vector for the NMI handler

"NMI-source based" sounds weird to me.

>    * @init: Optional __init* attributes for struct nmiaction
>    *
>    * Adds the provided handler to the list of handlers for the specified
> @@ -75,13 +77,14 @@ struct nmiaction {
>    *
>    * Return: 0 on success, or an error code on failure.
>    */
> -#define register_nmi_handler(t, fn, fg, n, init...)	\
> +#define register_nmi_handler(t, fn, fg, n, src, init...)	\
>   ({							\
>   	static struct nmiaction init fn##_na = {	\
>   		.list = LIST_HEAD_INIT(fn##_na.list),	\
>   		.handler = (fn),			\
>   		.name = (n),				\
>   		.flags = (fg),				\
> +		.source_vector = (src),			\
>   	};						\
>   	__register_nmi_handler((t), &fn##_na);		\
>   })
Please keep the line-ending backslashes (\) aligned.

I guess you want to keep the change minimal.