Re: [PATCH 1/3] hw/isa/vt82c686: Fix SCI routing

[Bernhard Beschow]

Am 31. Januar 2023 14:42:29 UTC schrieb BALATON Zoltan <balaton@eik.bme.hu>:
>On Sun, 29 Jan 2023, Bernhard Beschow wrote:
>> According to the PCI specification, the hardware is not supposed to use
>> PCI_INTERRUPT_PIN for interrupt routing. Use the dedicated ACPI
>> Interrupt Select register for SCI routing instead.
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>> hw/isa/vt82c686.c | 42 ++++++++++++++++++++++++++++++------------
>> 1 file changed, 30 insertions(+), 12 deletions(-)
>> 
>> diff --git a/hw/isa/vt82c686.c b/hw/isa/vt82c686.c
>> index 3f9bd0c04d..2189be6f20 100644
>> --- a/hw/isa/vt82c686.c
>> +++ b/hw/isa/vt82c686.c
>> @@ -46,6 +46,8 @@ struct ViaPMState {
>>     ACPIREGS ar;
>>     APMState apm;
>>     PMSMBus smb;
>> +
>> +    qemu_irq irq;
>> };
>> 
>> static void pm_io_space_update(ViaPMState *s)
>> @@ -148,18 +150,7 @@ static void pm_update_sci(ViaPMState *s)
>>                    ACPI_BITMASK_POWER_BUTTON_ENABLE |
>>                    ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
>>                    ACPI_BITMASK_TIMER_ENABLE)) != 0);
>> -    if (pci_get_byte(s->dev.config + PCI_INTERRUPT_PIN)) {
>> -        /*
>> -         * FIXME:
>> -         * Fix device model that realizes this PM device and remove
>> -         * this work around.
>> -         * The device model should wire SCI and setup
>> -         * PCI_INTERRUPT_PIN properly.
>> -         * If PIN# = 0(interrupt pin isn't used), don't raise SCI as
>> -         * work around.
>> -         */
>> -        pci_set_irq(&s->dev, sci_level);
>> -    }
>> +    qemu_set_irq(s->irq, sci_level);
>>     /* schedule a timer interruption if needed */
>>     acpi_pm_tmr_update(&s->ar, (s->ar.pm1.evt.en & 
>> ACPI_BITMASK_TIMER_ENABLE) &&
>>                        !(pmsts & ACPI_BITMASK_TIMER_STATUS));
>> @@ -213,6 +204,13 @@ static void via_pm_realize(PCIDevice *dev, Error **errp)
>>     acpi_pm1_cnt_init(&s->ar, &s->io, false, false, 2, false);
>> }
>> 
>> +static void via_pm_init(Object *obj)
>> +{
>> +    ViaPMState *s = VIA_PM(obj);
>> +
>> +    qdev_init_gpio_out(DEVICE(obj), &s->irq, 1);
>> +}
>> +
>> typedef struct via_pm_init_info {
>>     uint16_t device_id;
>> } ViaPMInitInfo;
>> @@ -238,6 +236,7 @@ static void via_pm_class_init(ObjectClass *klass, void 
>> *data)
>> static const TypeInfo via_pm_info = {
>>     .name          = TYPE_VIA_PM,
>>     .parent        = TYPE_PCI_DEVICE,
>> +    .instance_init = via_pm_init,
>>     .instance_size = sizeof(ViaPMState),
>>     .abstract      = true,
>>     .interfaces = (InterfaceInfo[]) {
>> @@ -568,6 +567,21 @@ static const VMStateDescription vmstate_via = {
>>     }
>> };
>> 
>> +static void via_isa_set_pm_irq(void *opaque, int n, int level)
>> +{
>> +    ViaISAState *s = opaque;
>> +    uint8_t irq = pci_get_byte(s->pm.dev.config + 0x42) & 0xf;
>> +
>> +    if (irq == 2) {
>
>unlikely(irq == 2) but do we really need to log this? It really should not 
>happen but if it does the guest is really broken and this will just flood the 
>log so I think you can just test for it in the if below and drop the log.

I'd prefer to log such guest errors precisely for above reason: To detect 
really broken guests. If it's really too much noise one can still filter the 
log with external tools such as grep.

Best regards,
Bernhard

>
>Regards,
>BALATON Zoltan
>
>> +        qemu_log_mask(LOG_GUEST_ERROR, "IRQ 2 for PM controller is 
>> reserved");
>> +        return;
>> +    }
>> +
>> +    if (irq != 0) {
>> +        qemu_set_irq(s->isa_irqs[irq], level);
>> +    }
>> +}
>> +
>> static void via_isa_init(Object *obj)
>> {
>>     ViaISAState *s = VIA_ISA(obj);
>> @@ -578,6 +592,8 @@ static void via_isa_init(Object *obj)
>>     object_initialize_child(obj, "uhci2", &s->uhci[1], 
>> TYPE_VT82C686B_USB_UHCI);
>>     object_initialize_child(obj, "ac97", &s->ac97, TYPE_VIA_AC97);
>>     object_initialize_child(obj, "mc97", &s->mc97, TYPE_VIA_MC97);
>> +
>> +    qdev_init_gpio_in_named(DEVICE(obj), via_isa_set_pm_irq, "sci", 1);
>> }
>> 
>> static const TypeInfo via_isa_info = {
>> @@ -664,6 +680,8 @@ static void via_isa_realize(PCIDevice *d, Error **errp)
>>     if (!qdev_realize(DEVICE(&s->pm), BUS(pci_bus), errp)) {
>>         return;
>>     }
>> +    qdev_connect_gpio_out(DEVICE(&s->pm), 0,
>> +                          qdev_get_gpio_in_named(DEVICE(d), "sci", 0));
>> 
>>     /* Function 5: AC97 Audio */
>>     qdev_prop_set_int32(DEVICE(&s->ac97), "addr", d->devfn + 5);
>>