Re: [Xen-devel] [PATCH v2 06/21] xen/arm: Allow virq != irq

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

Mostly spelling/grammar nits, a couple of questions but mostly looks
good.

On Thu, 2014-07-31 at 16:00 +0100, Julien Grall wrote:
> Actually Xen is assuming that the virtual IRQ will always be equal the IRQ.

"be equal to" or better "always be the same as".

> 
> Modify, route_guest_irq to take the virtual IRQ in parameter and let Xen

Spurious comma.

> assigned a different IRQ number. Also store the vIRQ in the desc action to

"assign".

> retrieve easily the IRQ target when we need to inject the interrupt.

"easily retrieve" (or "be able to easily retrieve")

> As DOM0 will get most the device, the vIRQ is equal to the IRQ.

"most of the devices".

I suppose the sentence should end with "in that case" or something?

> @@ -122,18 +129,20 @@ void __cpuinit init_secondary_IRQ(void)
>      BUG_ON(init_local_irq_data() < 0);
>  }
>  
> -static inline struct domain *irq_get_domain(struct irq_desc *desc)
> +static inline struct irq_guest *irq_get_guest_info(struct irq_desc *desc)
>  {
>      ASSERT(spin_is_locked(&desc->lock));
> -
> -    if ( !test_bit(_IRQ_GUEST, &desc->status) )
> -        return dom_xen;
> -
> +    ASSERT(test_bit(_IRQ_GUEST, &desc->status));
>      ASSERT(desc->action != NULL);
>  
>      return desc->action->dev_id;
>  }
>  
> +static inline struct domain *irq_get_domain(struct irq_desc *desc)
> +{
> +    return irq_get_guest_info(desc)->d;

Previously irq_get_domain could return dom_xen for !_IRQ_GUEST domains.
What happened to this logic? If it is never possible to get here with a
Xen owned IRQ then I think that is worth mentioning in the commit log
and/or a comment.

> @@ -206,7 +215,7 @@ void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, 
> int is_fiq)
>  
>          /* the irq cannot be a PPI, we only support delivery of SPIs to
>           * guests */
> -        vgic_vcpu_inject_spi(d, irq);
> +        vgic_vcpu_inject_spi(info->d, info->virq);

Could this function take an irq_guest* or are there other callers?

Ian.


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