Re: [Qemu-devel] [PATCH v5 2/3] spapr: introduce a IRQ controller backend to the machine

[Cédric Le Goater]

[ ... ] 

>> +static void spapr_irq_init_xics(sPAPRMachineState *spapr, Error **errp)
>> +{
>> +    MachineState *machine = MACHINE(spapr);
>> +    sPAPRMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
>> +    int nr_irqs = smc->irq->nr_irqs;
>> +    Error *local_err = NULL;
>> +
>> +    /* Initialize the MSI IRQ allocator. */
>> +    if (!SPAPR_MACHINE_GET_CLASS(spapr)->legacy_irq_allocation) {
>> +        spapr_irq_msi_init(spapr, XICS_IRQ_BASE + nr_irqs - SPAPR_IRQ_MSI);
>> +    }
> 
> I think this belongs in common code, rather than xics specific.

yes.
 
>> +
>> +    if (kvm_enabled()) {
>> +        if (machine_kernel_irqchip_allowed(machine) &&
>> +            !xics_kvm_init(spapr, &local_err)) {
>> +            spapr->icp_type = TYPE_KVM_ICP;
>> +            spapr->ics = spapr_ics_create(spapr, TYPE_ICS_KVM, nr_irqs,
>> +                                          &local_err);
>> +        }
>> +        if (machine_kernel_irqchip_required(machine) && !spapr->ics) {
>> +            error_prepend(&local_err,
>> +                          "kernel_irqchip requested but unavailable: ");
>> +            goto error;
>> +        }
>> +        error_free(local_err);
>> +        local_err = NULL;
>> +    }
>> +
>> +    if (!spapr->ics) {
> 
> When could this get called with spapr->ics already initialized?

if the code above succeeds when running with the KVM accel. 

What are thinking about ? introducing a xics-kvm backend ?   

C.

>> +        xics_spapr_init(spapr);
>> +        spapr->icp_type = TYPE_ICP;
>> +        spapr->ics = spapr_ics_create(spapr, TYPE_ICS_SIMPLE, nr_irqs,
>> +                                      &local_err);
>> +    }
>> +
>> +error:
>> +    error_propagate(errp, local_err);
>> +}
>> +