Re: [PATCH v3 02/11] x86/irq: Define NMI source vectors

[Xin Li <xin@zytor.com>]

On 6/28/2024 1:18 PM, Jacob Pan wrote:
> When NMI-source reporting is supported, each logical processor maintains
> a 16-bit NMI-source bitmap. It is up to the system software to assign NMI
> sources for their matching vector (bit position) in the bitmap.
> 
> Notice that NMI source vector is in a different namespace than the IDT
> vectors. Though they share the same programming interface/field in the
> NMI originator.
> 
> This initial allocation of the NMI sources are limited to local NMIs in
> that there is no external device NMI usage yet.
> 
> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
> ---
>   arch/x86/include/asm/irq_vectors.h | 28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
> 
> diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
> index 13aea8fc3d45..e4cd33bc4fef 100644
> --- a/arch/x86/include/asm/irq_vectors.h
> +++ b/arch/x86/include/asm/irq_vectors.h
> @@ -105,6 +105,34 @@
>   
>   #define NR_VECTORS			 256
>   
> +/*
> + * The NMI senders specify the NMI source vector as an 8bit integer in their

s/The NMI senders/NMI senders/

> + * vector field with NMI delivery mode. A local APIC receiving an NMI will
> + * set the corresponding bit in a 16bit bitmask, which is accumulated until
> + * the NMI is delivered.
> + * When a sender didn't specify an NMI source vector the source vector will
> + * be 0, which will result in bit 0 of the bitmask being set. For out of
> + * bounds vectors >= 16 bit 0 will also be set.
> + * When bit 0 is set, system software must invoke all registered NMI handlers
> + * as if NMI source feature is not enabled.

Add empty lines in the above paragraph.

> + *
> + * Vector 2 is reserved for matching IDT NMI vector where it may be hardcoded
> + * by some external devices.
> + *
> + * The NMI source vectors are sorted by descending priority with the exceptions
> + * of 0 and 2.
> + */
> +#define NMI_SOURCE_VEC_UNKNOWN		0
> +#define NMI_SOURCE_VEC_IPI_REBOOT	1	/* Crash reboot */
> +#define NMI_SOURCE_VEC_IDT_NMI		2	/* Match IDT NMI vector 2 */
> +#define NMI_SOURCE_VEC_IPI_SMP_STOP	3	/* Panic stop CPU */
> +#define NMI_SOURCE_VEC_IPI_BT		4	/* CPU backtrace */
> +#define NMI_SOURCE_VEC_PMI		5	/* PerfMon counters */
> +#define NMI_SOURCE_VEC_IPI_KGDB		6	/* KGDB */
> +#define NMI_SOURCE_VEC_IPI_MCE		7	/* MCE injection */
> +#define NMI_SOURCE_VEC_IPI_TEST		8	/* For remote and local IPIs */
> +#define NR_NMI_SOURCE_VECTORS		9

Fix alignment.

> +
>   #ifdef CONFIG_X86_LOCAL_APIC
>   #define FIRST_SYSTEM_VECTOR		POSTED_MSI_NOTIFICATION_VECTOR
>   #else