RE: [RFC PATCH 05/32] x86/traps: add exc_raise_irq() for VMX IRQ reinjection
From: Li, Xin3
Date: Mon Jan 09 2023 - 13:23:04 EST
> diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
> index 46f5e4e2a346..366b1675c033 100644
> --- a/arch/x86/include/asm/traps.h
> +++ b/arch/x86/include/asm/traps.h
> @@ -56,4 +56,6 @@ void __noreturn handle_stack_overflow(struct pt_regs
> *regs,
> void f (struct pt_regs *regs)
> typedef DECLARE_SYSTEM_INTERRUPT_HANDLER((*system_interrupt_handler));
>
> +int exc_raise_irq(struct pt_regs *regs, u32 vector);
> +
> #endif /* _ASM_X86_TRAPS_H */
> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
> index c35dd2b4d146..99386836b02e 100644
> --- a/arch/x86/kernel/traps.c
> +++ b/arch/x86/kernel/traps.c
> @@ -1536,6 +1536,24 @@ int external_interrupt(struct pt_regs *regs, unsigned
> int vector)
> return 0;
> }
>
> +#if IS_ENABLED(CONFIG_KVM_INTEL)
> +/*
> + * KVM VMX reinjects IRQ on its current stack, it's a sync call
> + * thus the values in the pt_regs structure are not used in
> + * executing IRQ handlers, except cs.RPL and flags.IF, which
> + * are both always 0 in the VMX IRQ reinjection context.
> + *
> + * However, the pt_regs structure is sometimes used in stack
> + * dump, e.g., show_regs(). So let the caller, i.e., KVM VMX
> + * decide how to initialize the input pt_regs structure.
> + */
> +int exc_raise_irq(struct pt_regs *regs, u32 vector)
> +{
> + return external_interrupt(regs, vector);
> +}
> +EXPORT_SYMBOL_GPL(exc_raise_irq);
> +#endif
Maybe it's better to simply export external_interrupt()
+EXPORT_SYMBOL_GPL(external_interrupt);
Then I don't need to add exc_raise_irq().
> +
> void __init trap_init(void)
> {
> /* Init cpu_entry_area before IST entries are set up */
> --
> 2.34.1