diff mbox series

[v2,5/6] spapr/xive: Activate StoreEOI at the source level

Message ID 20201005165147.526426-6-clg@kaod.org
State New
Headers show
Series spapr/xive: Activate StoreEOI in P10 compat guests | expand

Commit Message

Cédric Le Goater Oct. 5, 2020, 4:51 p.m. UTC
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.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
---
 hw/intc/spapr_xive.c | 1 +
 hw/ppc/spapr_irq.c   | 6 ++++++
 2 files changed, 7 insertions(+)

Comments

Greg Kurz Oct. 6, 2020, 5:06 p.m. UTC | #1
On Mon, 5 Oct 2020 18:51:46 +0200
Cédric Le Goater <clg@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 ?

> Signed-off-by: Cédric Le Goater <clg@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);
Cédric Le Goater Oct. 6, 2020, 5:41 p.m. UTC | #2
On 10/6/20 7:06 PM, Greg Kurz wrote:
> On Mon, 5 Oct 2020 18:51:46 +0200
> Cédric Le Goater <clg@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 <clg@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);
>
Greg Kurz Oct. 7, 2020, 7:26 a.m. UTC | #3
On Tue, 6 Oct 2020 19:41:28 +0200
Cédric Le Goater <clg@kaod.org> wrote:

> On 10/6/20 7:06 PM, Greg Kurz wrote:
> > On Mon, 5 Oct 2020 18:51:46 +0200
> > Cédric Le Goater <clg@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.
> 

Ok, then:

Reviewed-by: Greg Kurz <groug@kaod.org>

> C.
> 
> 
> >> Signed-off-by: Cédric Le Goater <clg@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);
> > 
>
diff mbox series

Patch

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);