RE: [PATCH RFC V2 24/37] hw/acpi: Update ACPI GED framework to support vCPU Hotplug

[Salil Mehta]

> From: Michael S. Tsirkin <mst@redhat.com>
> Sent: Tuesday, September 26, 2023 12:02 PM
> To: Salil Mehta <salil.mehta@huawei.com>
> Cc: qemu-devel@nongnu.org; qemu-arm@nongnu.org; maz@kernel.org; jean-
> philippe@linaro.org; Jonathan Cameron <jonathan.cameron@huawei.com>;
> lpieralisi@kernel.org; peter.maydell@linaro.org;
> richard.henderson@linaro.org; imammedo@redhat.com; andrew.jones@linux.dev;
> david@redhat.com; philmd@linaro.org; eric.auger@redhat.com;
> will@kernel.org; ardb@kernel.org; oliver.upton@linux.dev;
> pbonzini@redhat.com; gshan@redhat.com; rafael@kernel.org;
> borntraeger@linux.ibm.com; alex.bennee@linaro.org; linux@armlinux.org.uk;
> darren@os.amperecomputing.com; ilkka@os.amperecomputing.com;
> vishnu@os.amperecomputing.com; karl.heubaum@oracle.com;
> miguel.luis@oracle.com; salil.mehta@opnsrc.net; zhukeqian
> <zhukeqian1@huawei.com>; wangxiongfeng (C) <wangxiongfeng2@huawei.com>;
> wangyanan (Y) <wangyanan55@huawei.com>; jiakernel2@gmail.com;
> maobibo@loongson.cn; lixianglai@loongson.cn
> Subject: Re: [PATCH RFC V2 24/37] hw/acpi: Update ACPI GED framework to
> support vCPU Hotplug
> 
> On Tue, Sep 26, 2023 at 11:04:23AM +0100, Salil Mehta wrote:
> > ACPI GED shall be used to convey to the guest kernel about any CPU hot-
> (un)plug
> > events. Therefore, existing ACPI GED framework inside QEMU needs to be
> enhanced
> > to support CPU hotplug state and events.
> >
> > Co-developed-by: Salil Mehta <salil.mehta@huawei.com>
> 
> Co-developed with yourself?
> 
> didn't you co-develop this with xianglai li?

No, our effort is quite old ARM patch-set existed since the year 2020
without any change. Please check the original patch-set here:

https://lore.kernel.org/qemu-devel/20200613213629.21984-11-salil.mehta@huawei.com/


To be fair to the authors, it will not be right to add another SOB here.



> 
> Just include his S.O.B then, and drop the non-standard Co-developed-by.

Co-developed-by Tag has been added to ensure main authors of the patch
get highlighted clearly.


> 
> 
> 
> > Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> > 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>
> 
> 
> 
> > ---
> >  hw/acpi/generic_event_device.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> > diff --git a/hw/acpi/generic_event_device.c
> b/hw/acpi/generic_event_device.c
> > index ad252e6a91..0266733a54 100644
> > --- a/hw/acpi/generic_event_device.c
> > +++ b/hw/acpi/generic_event_device.c
> > @@ -12,6 +12,7 @@
> >  #include "qemu/osdep.h"
> >  #include "qapi/error.h"
> >  #include "hw/acpi/acpi.h"
> > +#include "hw/acpi/cpu.h"
> >  #include "hw/acpi/generic_event_device.h"
> >  #include "hw/irq.h"
> >  #include "hw/mem/pc-dimm.h"
> > @@ -239,6 +240,8 @@ static void acpi_ged_device_plug_cb(HotplugHandler
> *hotplug_dev,
> >          } else {
> >              acpi_memory_plug_cb(hotplug_dev, &s->memhp_state, dev,
> errp);
> >          }
> > +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> > +        acpi_cpu_plug_cb(hotplug_dev, &s->cpuhp_state, dev, errp);
> >      } else {
> >          error_setg(errp, "virt: device plug request for unsupported
> device"
> >                     " type: %s", object_get_typename(OBJECT(dev)));
> > @@ -253,6 +256,8 @@ static void acpi_ged_unplug_request_cb(HotplugHandler
> *hotplug_dev,
> >      if ((object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) &&
> >                         !(object_dynamic_cast(OBJECT(dev),
> TYPE_NVDIMM)))) {
> >          acpi_memory_unplug_request_cb(hotplug_dev, &s->memhp_state, dev,
> errp);
> > +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> > +        acpi_cpu_unplug_request_cb(hotplug_dev, &s->cpuhp_state, dev,
> errp);
> >      } else {
> >          error_setg(errp, "acpi: device unplug request for unsupported
> device"
> >                     " type: %s", object_get_typename(OBJECT(dev)));
> > @@ -266,6 +271,8 @@ static void acpi_ged_unplug_cb(HotplugHandler
> *hotplug_dev,
> >
> >      if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> >          acpi_memory_unplug_cb(&s->memhp_state, dev, errp);
> > +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
> > +        acpi_cpu_unplug_cb(&s->cpuhp_state, dev, errp);
> >      } else {
> >          error_setg(errp, "acpi: device unplug for unsupported device"
> >                     " type: %s", object_get_typename(OBJECT(dev)));
> > @@ -277,6 +284,7 @@ static void acpi_ged_ospm_status(AcpiDeviceIf *adev,
> ACPIOSTInfoList ***list)
> >      AcpiGedState *s = ACPI_GED(adev);
> >
> >      acpi_memory_ospm_status(&s->memhp_state, list);
> > +    acpi_cpu_ospm_status(&s->cpuhp_state, list);
> >  }
> >
> >  static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits
> ev)
> > @@ -291,6 +299,8 @@ static void acpi_ged_send_event(AcpiDeviceIf *adev,
> AcpiEventStatusBits ev)
> >          sel = ACPI_GED_PWR_DOWN_EVT;
> >      } else if (ev & ACPI_NVDIMM_HOTPLUG_STATUS) {
> >          sel = ACPI_GED_NVDIMM_HOTPLUG_EVT;
> > +    } else if (ev & ACPI_CPU_HOTPLUG_STATUS) {
> > +        sel = ACPI_GED_CPU_HOTPLUG_EVT;
> >      } else {
> >          /* Unknown event. Return without generating interrupt. */
> >          warn_report("GED: Unsupported event %d. No irq injected", ev);
> > --
> > 2.34.1