Re: In kernel PIC support: kernel patch

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Dong, Eddie wrote:
>>> +/* 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.
>
>   

GSI is good enough.   However, we want not to use the name gsi in the 
code, since other archs will not hace it.  Just add a comment indicating 
that for x86 and ia64 the irqchip number is interpreted according to the 
gsi conventions.



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