Re: [PATCH] x86/boot/compressed: Register NMI handler in EFI boot loader

[Ingo Molnar]

* Zeng Heng <zengheng4@xxxxxxxxxx> wrote:

> +void do_boot_nmi_fault(struct pt_regs *regs, unsigned long error_code)
> +{
> +	/* ignore */
> +}
> diff --git a/arch/x86/boot/compressed/idt_64.c b/arch/x86/boot/compressed/idt_64.c
> index 6debb816e83d..b169c9728d52 100644
> --- a/arch/x86/boot/compressed/idt_64.c
> +++ b/arch/x86/boot/compressed/idt_64.c
> @@ -60,6 +60,7 @@ void load_stage2_idt(void)
>  {
>  	boot_idt_desc.address = (unsigned long)boot_idt;
>  
> +	set_idt_entry(X86_TRAP_NMI, boot_nmi_fault);
>  	set_idt_entry(X86_TRAP_PF, boot_page_fault);

So it's a bit sad to install a dummy handler that does nothing, while 
something clearly sent an NMI and expects an intelligent reaction - OTOH 
the unexpected NMIs from from watchdog during a kdump clearly make things 
worse by crashing the bootup.

Anyway, I cannot think of a better response here that the boot loading code 
could do either, so I've applied your fix to tip:x86/boot.

Thanks,

	Ingo