Hard limit on 256 IRQs in qtest

Hard limit on 256 IRQs in qtest

[Roque Arcudia Hernandez]

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Hello,

To write a qtest for an SoC using ARM GICv3 as interrupt controller the
qtest infrastructure is short on IRQs.

File tests/qtest/libqtest.c defines:

#define MAX_IRQ 256

Which is the number of elements in the array that is used to keep track of
the value of the irq gpio:

    bool irq_level[MAX_IRQ];

The GICv3 can take up to 1020. The SoC we are trying to emulate uses more
than the current 256 limit we can observe at the GIC input. If we focus
just on the external interrupt range the GIC would need 1020 - 32 = 988
IRQs. Will it be OK to make this change to the qtest infrastructure?

Thanks,

Roque

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Re: Hard limit on 256 IRQs in qtest

[Thomas Huth]

On 21/07/2022 18.17, Roque Arcudia Hernandez wrote:
> Hello,
> 
> 
> To write a qtest for an SoC using ARM GICv3 as interrupt controller the 
> qtest infrastructure is short on IRQs.
> 
> File tests/qtest/libqtest.c defines:
> 
> #define MAX_IRQ 256
> 
> Which is the number of elements in the array that is used to keep track of 
> the value of the irq gpio:
> 
>      bool irq_level[MAX_IRQ];
> 
> The GICv3 can take up to 1020. The SoC we are trying to emulate uses more 
> than the current 256 limit we can observe at the GIC input. If we focus just 
> on the external interrupt range the GIC would need 1020 - 32 = 988 IRQs. 
> Will it be OK to make this change to the qtest infrastructure?

I guess it should be fine. Just not that you have to adjust the same #define 
in softmmu/qtest.c, too.

  Thomas