RE: [PATCH V6 4/9] hw/acpi: Init GED framework with CPU hotplug events

[Salil Mehta via <qemu-devel@nongnu.org>]

Hi Igor,
Sorry, I realized I missed to reply this review comment.

> From: Igor Mammedov <imammedo@redhat.com>
> Sent: Friday, October 27, 2023 3:08 PM
> To: Salil Mehta <salil.mehta@huawei.com>
> 
> On Fri, 13 Oct 2023 11:51:24 +0100
> Salil Mehta <salil.mehta@huawei.com> wrote:
> 
> > ACPI GED(as described in the ACPI 6.2 spec) can be used to generate ACPI events
> > when OSPM/guest receives an interrupt listed in the _CRS object of GED. OSPM
> > then maps or demultiplexes the event by evaluating _EVT method.
> >
> > This change adds the support of CPU hotplug event initialization in the
> > existing GED framework.
> >
> > Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
> > Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
> > Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Reviewed-by: Gavin Shan <gshan@redhat.com>
> > Reviewed-by: David Hildenbrand <david@redhat.com>
> > Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
> > Tested-by: Xianglai Li <lixianglai@loongson.cn>
> > ---
> >  hw/acpi/generic_event_device.c         | 8 ++++++++
> >  include/hw/acpi/generic_event_device.h | 5 +++++
> >  2 files changed, 13 insertions(+)
> >
> > diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> > index a3d31631fe..d2fa1d0e4a 100644
> > --- a/hw/acpi/generic_event_device.c
> > +++ b/hw/acpi/generic_event_device.c
> > @@ -25,6 +25,7 @@ static const uint32_t ged_supported_events[] = {
> >      ACPI_GED_MEM_HOTPLUG_EVT,
> >      ACPI_GED_PWR_DOWN_EVT,
> >      ACPI_GED_NVDIMM_HOTPLUG_EVT,
> > +    ACPI_GED_CPU_HOTPLUG_EVT,
> >  };
> >
> >  /*
> > @@ -400,6 +401,13 @@ static void acpi_ged_initfn(Object *obj)
> >      memory_region_init_io(&ged_st->regs, obj, &ged_regs_ops, ged_st,
> >                            TYPE_ACPI_GED "-regs", ACPI_GED_REG_COUNT);
> >      sysbus_init_mmio(sbd, &ged_st->regs);
> > +
> > +    s->cpuhp.device = OBJECT(s);
> ain't OBJECT(s) == OBJECT(dev)m


Thanks for pointing. And going deeper to looks this is *stray* and
surprisingly has been lurking since I first floated the RFC V1
in Jun 2020. Sorry I missed it in earlier context although David
did point to this.

Salil.


> > +    memory_region_init(&s->container_cpuhp, OBJECT(dev), "cpuhp
> container",
> > +                       ACPI_CPU_HOTPLUG_REG_LEN);
> > +    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->container_cpuhp);
> > +    cpu_hotplug_hw_init(&s->container_cpuhp, OBJECT(dev),
> > +                        &s->cpuhp_state, 0);
> 
> we really should refactor GED to initfn/realizefn pattern.
> then at create_acpi_ged() one would enable cpu_hotplug event
> and later realizefs would call cpu_hotplug_hw_init() if event is enabled.


Maybe. Why not instance_init() ?


> >  }
> >
> >  static void acpi_ged_class_init(ObjectClass *class, void *data)
> > diff --git a/include/hw/acpi/generic_event_device.h
> b/include/hw/acpi/generic_event_device.h
> > index ba84ce0214..a803ea818e 100644
> > --- a/include/hw/acpi/generic_event_device.h
> > +++ b/include/hw/acpi/generic_event_device.h
> > @@ -60,6 +60,7 @@
> >  #define HW_ACPI_GENERIC_EVENT_DEVICE_H
> >
> >  #include "hw/sysbus.h"
> > +#include "hw/acpi/cpu_hotplug.h"
> >  #include "hw/acpi/memory_hotplug.h"
> >  #include "hw/acpi/ghes.h"
> >  #include "qom/object.h"
> > @@ -95,6 +96,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
> >  #define ACPI_GED_MEM_HOTPLUG_EVT   0x1
> >  #define ACPI_GED_PWR_DOWN_EVT      0x2
> >  #define ACPI_GED_NVDIMM_HOTPLUG_EVT 0x4
> > +#define ACPI_GED_CPU_HOTPLUG_EVT    0x8
> >
> >  typedef struct GEDState {
> >      MemoryRegion evt;
> > @@ -106,6 +108,9 @@ struct AcpiGedState {
> >      SysBusDevice parent_obj;
> >      MemHotplugState memhp_state;
> >      MemoryRegion container_memhp;
> > +    CPUHotplugState cpuhp_state;
> > +    MemoryRegion container_cpuhp;
> > +    AcpiCpuHotplug cpuhp;
> 
> how about merging CPUHotplugState and AcpiCpuHotplug
> and isolating AcpiCpuHotplug::sts to x86 legacy hotplug code only?
> 
> then you won't have to pull in 2 states (one of which includes
> GPE specific array that's not applicable to GED)

To be frank, I do not remember the context what I was trying to do
4 years back. But above looks stray and will remove it.


Thanks
Salil.