Subject: Re: [PATCH v6 02/29] x86/apic: Add irq_cfg::delivery_mode

From: Thomas Gleixner <[email-masked]>
Date: Fri, 06 May 2022 21:53:54 +0200

On Thu, May 05 2022 at 16:59, Ricardo Neri wrote:
> Currently, the delivery mode of all interrupts is set to the mode of the
> APIC driver in use. There are no restrictions in hardware to configure the
> delivery mode of each interrupt individually. Also, certain IRQs need
> to be

s/IRQ/interrupt/ Changelogs can do without acronyms.

> configured with a specific delivery mode (e.g., NMI).
>
> Add a new member, delivery_mode, to struct irq_cfg. Subsequent changesets
> will update every irq_domain to set the delivery mode of each IRQ to that
> specified in its irq_cfg data.
>
> To keep the current behavior, when allocating an IRQ in the root
> domain

The root domain does not allocate an interrupt. The root domain
allocates a vector for an interrupt. There is a very clear and technical
destinction. Can you please be more careful about the wording?

> --- a/arch/x86/kernel/apic/vector.c
> +++ b/arch/x86/kernel/apic/vector.c
> @@ -567,6 +567,7 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
>  		irqd->chip_data = apicd;
>  		irqd->hwirq = virq + i;
>  		irqd_set_single_target(irqd);
> +

Stray newline.

>  		/*
>  		 * Prevent that any of these interrupts is invoked in
>  		 * non interrupt context via e.g. generic_handle_irq()
> @@ -577,6 +578,14 @@ static int x86_vector_alloc_irqs(struct irq_domain *domain, unsigned int virq,
>  		/* Don't invoke affinity setter on deactivated interrupts */
>  		irqd_set_affinity_on_activate(irqd);
>  
> +		/*
> +		 * Initialize the delivery mode of this irq to match the

s/irq/interrupt/

> +		 * default delivery mode of the APIC. Children irq domains
> +		 * may take the delivery mode from the individual irq
> +		 * configuration rather than from the APIC driver.
> +		 */
> +		apicd->hw_irq_cfg.delivery_mode = apic->delivery_mode;
> +
>  		/*
>  		 * Legacy vectors are already assigned when the IOAPIC
>  		 * takes them over. They stay on the same vector. This is