Re: In kernel PIC support: kernel patch

Dong, Eddie
2007-07-03T04:45:32Z

>> +/* for KVM_SET_IRQ_LEVEL */
>> +struct kvm_irq_level {
>> + __u32 irq;
>> + __u32 level;
>> +};
>>
>
> Please add an irqchip index, so this can be used for
> configurations with
> multiple irqchips (likely ioapics). You'll also need to add
> padding so
> the structure is 64-bit aligned.
>
Adding irqchip index is one way, another way is to just use gsi index
(probably rename irq to gsi). I.e. In X86, gsi 0-15 is for both PIC and
IOAPIC
and gsi 16-23 is for IOAPIC0 only, gsi 24---xxx can be for ioapic 1,2,
.. n.

In IA64, gsi 0-xxx is just for IOAPIC 0,1, .. n.

Since ACPI already defined gsi, so do we really want to use irqchip
index?
They are functionally equvalent but gsi is cross architecture neutral,
while
irqchip index is very X86 specific.

Eddie