Re: [patch 4/5] x86/apic: Convert to IRQCHIP_MOVE_DEFERRED

[Wei Liu]

On Tue, Dec 10, 2024 at 11:34:15AM +0100, Thomas Gleixner wrote:
> Instead of marking individual interrupts as safe to be migrated in
> arbitrary contexts, mark the interrupt chips, which require the interrupt
> to be moved in actual interrupt context, with the new IRQCHIP_MOVE_DEFERRED
> flag. This makes more sense because this is a per interrupt chip property
> and not restricted to individual interrupts.
> 
> That flips the logic from the historical opt-out to a opt-in model. This is
> simpler to handle for other architectures, which default to unrestricted
> affinity setting. It also allows to cleanup the redundant core logic
> significantly.
> 
> All interrupt chips, which belong to a top-level domain sitting directly on
> top of the x86 vector domain are marked accordingly, unless the related
> setup code marks the interrupts with IRQ_MOVE_PCNTXT, i.e. XEN.
> 
> No functional change intended.
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
[...]
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -2053,6 +2053,7 @@ static struct irq_chip hv_msi_irq_chip =
>  	.irq_set_affinity	= irq_chip_set_affinity_parent,
>  #ifdef CONFIG_X86
>  	.irq_ack		= irq_chip_ack_parent,
> +	.flags			= IRQCHIP_MOVE_DEFERRED,
>  #elif defined(CONFIG_ARM64)
>  	.irq_eoi		= irq_chip_eoi_parent,
>  #endif

Acked-by: Wei Liu <wei.liu@xxxxxxxxxx>