On 10/6/20 7:06 PM, Greg Kurz wrote:
> On Mon, 5 Oct 2020 18:51:46 +0200
> Cédric Le Goater <c...@kaod.org> wrote:
>
>> When the StoreEOI capability is "on", the H_INT_GET_SOURCE_INFO will
>> set the StoreEOI flag for all sources. This could be an issue if
>> StoreEOI is not supported on a specific source, of a passthrough
>> device for instance. In that case, we could either introduce a new KVM
>> ioctl to query the characteristics of the source at the HW level or
>> deactivate StoreEOI on the machine.
>>
>> This is theoretically unsafe on a POWER9 host but it still runs.
>>
>
> Patch looks good but as said before, what is the likeliness of something
> really painful to happen on a POWER9 host ?
Nothing will happen because POWER9 systems deactivate StoreEOI. You need
a custom skiboot to add it back.
C.
>> Signed-off-by: Cédric Le Goater <c...@kaod.org>
>> ---
>> hw/intc/spapr_xive.c | 1 +
>> hw/ppc/spapr_irq.c | 6 ++++++
>> 2 files changed, 7 insertions(+)
>>
>> diff --git a/hw/intc/spapr_xive.c b/hw/intc/spapr_xive.c
>> index 1fa09f287ac0..41f2719ff93a 100644
>> --- a/hw/intc/spapr_xive.c
>> +++ b/hw/intc/spapr_xive.c
>> @@ -280,6 +280,7 @@ static void spapr_xive_instance_init(Object *obj)
>> SpaprXive *xive = SPAPR_XIVE(obj);
>>
>> object_initialize_child(obj, "source", &xive->source, TYPE_XIVE_SOURCE);
>> + object_property_add_alias(obj, "flags", OBJECT(&xive->source), "flags");
>>
>> object_initialize_child(obj, "end_source", &xive->end_source,
>> TYPE_XIVE_END_SOURCE);
>> diff --git a/hw/ppc/spapr_irq.c b/hw/ppc/spapr_irq.c
>> index f59960339ec3..cdf9f9df4173 100644
>> --- a/hw/ppc/spapr_irq.c
>> +++ b/hw/ppc/spapr_irq.c
>> @@ -325,9 +325,14 @@ void spapr_irq_init(SpaprMachineState *spapr, Error
>> **errp)
>>
>> if (spapr->irq->xive) {
>> uint32_t nr_servers = spapr_max_server_number(spapr);
>> + uint64_t flags = 0;
>> DeviceState *dev;
>> int i;
>>
>> + if (spapr_get_cap(spapr, SPAPR_CAP_STOREEOI) == SPAPR_CAP_ON) {
>> + flags |= XIVE_SRC_STORE_EOI;
>> + }
>> +
>> dev = qdev_new(TYPE_SPAPR_XIVE);
>> qdev_prop_set_uint32(dev, "nr-irqs", smc->nr_xirqs +
>> SPAPR_XIRQ_BASE);
>> /*
>> @@ -337,6 +342,7 @@ void spapr_irq_init(SpaprMachineState *spapr, Error
>> **errp)
>> qdev_prop_set_uint32(dev, "nr-ends", nr_servers << 3);
>> object_property_set_link(OBJECT(dev), "xive-fabric", OBJECT(spapr),
>> &error_abort);
>> + object_property_set_int(OBJECT(dev), "flags", flags, &error_abort);
>> sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
>>
>> spapr->xive = SPAPR_XIVE(dev);
>
