[ ... ]
>>>> +
>>>> +static qemu_irq spapr_qirq_dual(sPAPRMachineState *spapr, int irq)
>>>> +{
>>>> + return spapr_irq_current(spapr)->qirq(spapr, irq);
>>>
>>> Urgh... I don't think this is going to work. IIRC the various devices
>>> (PHB, VIO, etc.) are wired up to their qirqs at realize() time, so if
>>> you reboot from a XIVE guest to XICS guest (or maybe the other way
>>> around) the peripherals won't be able to signal irqs in the new
>>> scheme.
>>
>> It does. The IRQ numbers are claimed in both backends.
>
> Yes, I realize that, but the two backends still have their own set of
> qirqs, which have their own set_irq routines associated with them.
>
>> This is the problem since the very beginning. For reset and migration
>> to work, we need to keep in sync the IRQ number space of the machine
>> and the different interrupt controllers.
>
> Sure, we have the numbers in sync, but that won't help if when the
> peripherals do a qemu_irq_pulse() it goes to the wrong backend's
> trigger routine.
Ah. You mean that the devices could bypass the sPAPR IRQ layer and
trigger the IRQ directly from the IRQ controller model ? it's not
the case today.
I agree that having a common set of qirqs and a qemu_irq handler
doing the dispatch on the selected interrupt contoller model is
good idea. I didn't go in that direction because KVM brings additional
head aches.
Where would put the qirqs ? at the machine level I suppose.
Thanks,
C.
>
>>
>> C.
>>
>>
>>> I think instead we need a common set of qirqs, whose set_irq routine
>>> looks at whether to signal XICS or XIVE. FOr now I think the easiest
>>> approach is to layer those on top of the existing XICS or XIVE
>>> specific qirqs. Later we might want to remove the (input) qirqs
>>> entirely from the XICS and XIVE subsystems, instead having just
>>> explicit trigger functions. Then spapr will always supply the qirqs
>>> which call into one or the other.
>>>
>>>> +}
>>>> +
>>>> +static void spapr_irq_print_info_dual(sPAPRMachineState *spapr, Monitor
>>>> *mon)
>>>> +{
>>>> + spapr_irq_current(spapr)->print_info(spapr, mon);
>>>> +}
>>>> +
>>>> +static void spapr_irq_dt_populate_dual(sPAPRMachineState *spapr,
>>>> + uint32_t nr_servers, void *fdt,
>>>> + uint32_t phandle)
>>>> +{
>>>> + spapr_irq_current(spapr)->dt_populate(spapr, nr_servers, fdt,
>>>> phandle);
>>>> +}
>>>> +
>>>> +static Object *spapr_irq_cpu_intc_create_dual(sPAPRMachineState *spapr,
>>>> + Object *cpu, Error **errp)
>>>> +{
>>>> + Error *local_err = NULL;
>>>> +
>>>> + spapr_irq_xive.cpu_intc_create(spapr, cpu, &local_err);
>>>> + if (local_err) {
>>>> + error_propagate(errp, local_err);
>>>> + return NULL;
>>>> + }
>>>> +
>>>> + /* Default to XICS interrupt mode */
>>>> + return spapr_irq_xics.cpu_intc_create(spapr, cpu, errp);
>>>> +}
>>>> +
>>>> +static int spapr_irq_post_load_dual(sPAPRMachineState *spapr, int
>>>> version_id)
>>>> +{
>>>> + /*
>>>> + * Force a reset of the XIVE backend after migration. The machine
>>>> + * defaults to XICS at startup.
>>>> + */
>>>> + if (spapr_ovec_test(spapr->ov5_cas, OV5_XIVE_EXPLOIT)) {
>>>> + spapr_irq_xive.reset(spapr, &error_fatal);
>>>> + }
>>>> +
>>>> + return spapr_irq_current(spapr)->post_load(spapr, version_id);
>>>> +}
>>>> +
>>>> +static void spapr_irq_reset_dual(sPAPRMachineState *spapr, Error **errp)
>>>> +{
>>>> + /*
>>>> + * Reset the interrupt mode selected by CAS.
>>>> + */
>>>> + spapr_irq_current(spapr)->reset(spapr, errp);
>>>> +}
>>>> +
>>>> +/*
>>>> + * Define values in sync with the XIVE and XICS backend
>>>> + */
>>>> +#define SPAPR_IRQ_DUAL_NR_IRQS 0x2000
>>>> +#define SPAPR_IRQ_DUAL_NR_MSIS (SPAPR_IRQ_DUAL_NR_IRQS -
>>>> SPAPR_IRQ_MSI)
>>>> +
>>>> +sPAPRIrq spapr_irq_dual = {
>>>> + .nr_irqs = SPAPR_IRQ_DUAL_NR_IRQS,
>>>> + .nr_msis = SPAPR_IRQ_DUAL_NR_MSIS,
>>>> + .ov5 = SPAPR_OV5_XIVE_BOTH,
>>>> +
>>>> + .init = spapr_irq_init_dual,
>>>> + .claim = spapr_irq_claim_dual,
>>>> + .free = spapr_irq_free_dual,
>>>> + .qirq = spapr_qirq_dual,
>>>> + .print_info = spapr_irq_print_info_dual,
>>>> + .dt_populate = spapr_irq_dt_populate_dual,
>>>> + .cpu_intc_create = spapr_irq_cpu_intc_create_dual,
>>>> + .post_load = spapr_irq_post_load_dual,
>>>> + .reset = spapr_irq_reset_dual,
>>>> +};
>>>> +
>>>> /*
>>>> * sPAPR IRQ frontend routines for devices
>>>> */
>>>
>>
>
