Re: [Qemu-devel] [PATCH-for-4.2 v8 3/9] hw/acpi: Add ACPI Generic Event Device Support

[Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>]

Hi Igor,

> -----Original Message-----
> From: Qemu-devel
> [mailto:qemu-devel-bounces+shameerali.kolothum.thodi=huawei.com@nongn
> u.org] On Behalf Of Igor Mammedov
> Sent: 30 July 2019 16:25
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: peter.maydell@linaro.org; sameo@linux.intel.com;
> ard.biesheuvel@linaro.org; shannon.zhaosl@gmail.com;
> qemu-devel@nongnu.org; xuwei (O) <xuwei5@huawei.com>; Linuxarm
> <linuxarm@huawei.com>; eric.auger@redhat.com; qemu-arm@nongnu.org;
> Paolo Bonzini <pbonzini@redhat.com>; sebastien.boeuf@intel.com;
> lersek@redhat.com
> Subject: Re: [Qemu-devel] [PATCH-for-4.2 v8 3/9] hw/acpi: Add ACPI Generic
> Event Device Support
> 
> On Fri, 26 Jul 2019 11:45:13 +0100
> Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> wrote:
> 
> > From: Samuel Ortiz <sameo@linux.intel.com>
> >
> > The ACPI Generic Event Device (GED) is a hardware-reduced specific
> > device[ACPI v6.1 Section 5.6.9] that handles all platform events,
> > including the hotplug ones. This patch generates the AML code that
> > defines GEDs.
> >
> > Platforms need to specify their own GED Event bitmap to describe
> > what kind of events they want to support through GED.  Also this
> > uses a a single interrupt for the  GED device, relying on IO
> > memory region to communicate the type of device affected by the
> > interrupt. This way, we can support up to 32 events with a unique
> > interrupt.
> >
> > This supports only memory hotplug for now.
> >
> 
> > diff --git a/hw/acpi/generic_event_device.c
> b/hw/acpi/generic_event_device.c
> > new file mode 100644
> > index 0000000000..7902e9d706
> > --- /dev/null
> > +++ b/hw/acpi/generic_event_device.c
> [...]
> > +void build_ged_aml(Aml *table, const char *name, HotplugHandler
> *hotplug_dev,
> > +                   uint32_t ged_irq, AmlRegionSpace rs)
> > +{
> [...]
> > +
> > +        if (ged_events) {
> > +            error_report("GED: Unsupported events specified");
> > +            exit(1);
> I'd use error_abort instead, since it's programing error, if you have to respin
> series.

Ok.

> > +        }
> > +    }
> > +
> > +    /* Append _EVT method */
> > +    aml_append(dev, evt);
> > +
> > +    aml_append(table, dev);
> > +}
> > +
> [...]
> > +static void acpi_ged_device_realize(DeviceState *dev, Error **errp)
> > +{
> > +    AcpiGedState *s = ACPI_GED(dev);
> > +
> > +    assert(s->ged_base);
> > +    acpi_ged_init(get_system_memory(), dev, &s->ged_state);
> 
> calling get_system_memory() from device code used to be a reason for
> rejecting patch,
> I'm not sure what suggest though.
> 
> Maybe Paolo could suggest something.

How about using object_property_set_link()? Something like below.

------8-----
diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
index f00b0ab14b..eb1ed38f4a 100644
--- a/hw/acpi/generic_event_device.c
+++ b/hw/acpi/generic_event_device.c
@@ -229,11 +229,12 @@ static void acpi_ged_device_realize(DeviceState *dev, Error **errp)
     AcpiGedState *s = ACPI_GED(dev);
 
     assert(s->ged_base);
-    acpi_ged_init(get_system_memory(), dev, &s->ged_state);
+    assert(s->sys_mem);
+    acpi_ged_init(s->sys_mem, dev, &s->ged_state);
 
     if (s->memhp_state.is_enabled) {
         assert(s->memhp_base);
-        acpi_memory_hotplug_init(get_system_memory(), OBJECT(dev),
+        acpi_memory_hotplug_init(s->sys_mem, OBJECT(dev),
                                  &s->memhp_state,
                                  s->memhp_base);
     }
@@ -245,6 +246,8 @@ static Property acpi_ged_properties[] = {
      * because GED handles memory hotplug event and acpi-mem-hotplug
      * memory region gets initialized when GED device is realized.
      */
+    DEFINE_PROP_LINK("memory", AcpiGedState, sys_mem, TYPE_MEMORY_REGION,
+                     MemoryRegion *),
     DEFINE_PROP_UINT64("memhp-base", AcpiGedState, memhp_base, 0),
     DEFINE_PROP_BOOL("memory-hotplug-support", AcpiGedState,
                      memhp_state.is_enabled, true),
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 73a758d9a9..0cbaf6c6e1 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -529,8 +529,12 @@ static inline DeviceState *create_acpi_ged(VirtMachineState *vms, qemu_irq *pic)
     DeviceState *dev;
     int irq = vms->irqmap[VIRT_ACPI_GED];
     uint32_t event = ACPI_GED_MEM_HOTPLUG_EVT | ACPI_GED_PWR_DOWN_EVT;
+    MemoryRegion *sys_mem = get_system_memory();
 
     dev = DEVICE(object_new(TYPE_ACPI_GED));
+
+    object_property_set_link(OBJECT(dev), OBJECT(sys_mem),
+                             "memory", &error_abort);
     qdev_prop_set_uint64(dev, "memhp-base",
                          vms->memmap[VIRT_PCDIMM_ACPI].base);
     qdev_prop_set_uint64(dev, "ged-base", vms->memmap[VIRT_ACPI_GED].base);
diff --git a/include/hw/acpi/generic_event_device.h b/include/hw/acpi/generic_event_device.h
index 63104f1344..f1f2f337f7 100644
--- a/include/hw/acpi/generic_event_device.h
+++ b/include/hw/acpi/generic_event_device.h
@@ -89,6 +89,7 @@ typedef struct GEDState {
 
 typedef struct AcpiGedState {
     DeviceClass parent_obj;
+    MemoryRegion *sys_mem;
     MemHotplugState memhp_state;
     hwaddr memhp_base;
     hwaddr ged_base;

---8----