Re: [Qemu-arm] [PATCH v4 4/8] hw/arm/virt: Add memory hotplug framework

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Igor Mammedov [mailto:address@hidden
> Sent: 02 May 2019 17:19
> To: Shameerali Kolothum Thodi <address@hidden>
> Cc: address@hidden; address@hidden;
> address@hidden; address@hidden;
> address@hidden; address@hidden;
> address@hidden; xuwei (O) <address@hidden>;
> address@hidden; address@hidden; Linuxarm
> <address@hidden>
> Subject: Re: [PATCH v4 4/8] hw/arm/virt: Add memory hotplug framework
> 
> On Tue, 9 Apr 2019 11:29:31 +0100
> Shameer Kolothum <address@hidden> wrote:
> 
> > From: Eric Auger <address@hidden>
> >
> > This patch adds the memory hot-plug/hot-unplug infrastructure
> > in machvirt. The device memory is not yet exposed to the Guest
> > either though DT or ACPI and hence both cold/hot plug of memory
> s/though/through/

Sure.

> > is explicitly disabled for now.
> >
> > Signed-off-by: Eric Auger <address@hidden>
> > Signed-off-by: Kwangwoo Lee <address@hidden>
> > Signed-off-by: Shameer Kolothum <address@hidden>
> > ---
> >  default-configs/arm-softmmu.mak |  3 +++
> >  hw/arm/virt.c                   | 45
> ++++++++++++++++++++++++++++++++++++++++-
> >  2 files changed, 47 insertions(+), 1 deletion(-)
> >
> > diff --git a/default-configs/arm-softmmu.mak
> b/default-configs/arm-softmmu.mak
> > index 613d19a..9f4b803 100644
> > --- a/default-configs/arm-softmmu.mak
> > +++ b/default-configs/arm-softmmu.mak
> > @@ -160,3 +160,6 @@ CONFIG_MUSICPAL=y
> >
> >  # for realview and versatilepb
> >  CONFIG_LSI_SCSI_PCI=y
> > +
> > +CONFIG_MEM_DEVICE=y
> > +CONFIG_DIMM=y
> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> > index ce2664a..da516b3 100644
> > --- a/hw/arm/virt.c
> > +++ b/hw/arm/virt.c
> > @@ -61,6 +61,8 @@
> >  #include "hw/arm/smmuv3.h"
> >  #include "hw/acpi/acpi.h"
> >  #include "target/arm/internals.h"
> > +#include "hw/mem/pc-dimm.h"
> > +#include "hw/mem/nvdimm.h"
> >
> >  #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
> >      static void virt_##major##_##minor##_class_init(ObjectClass *oc, \
> > @@ -1806,6 +1808,34 @@ static const CPUArchIdList
> *virt_possible_cpu_arch_ids(MachineState *ms)
> >      return ms->possible_cpus;
> >  }
> >
> > +static void virt_memory_pre_plug(HotplugHandler *hotplug_dev,
> DeviceState *dev,
> > +                                 Error **errp)
> > +{
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +        error_setg(errp, "memory cold/hot plug is not yet supported");
> > +        return;
> > +    }
> add comment here why it's needed.

Ok.

> 
> > +
> > +    pc_dimm_pre_plug(PC_DIMM(dev), MACHINE(hotplug_dev), NULL,
> errp);
> maybe before calling this there probably should be check if acpi is enabled.
> 
> not sure if arm/virt board honors -no-acpi CLI option.

Ok. I will check this

Thanks,
Shameer
 
> > +}
> > +
> > +static void virt_memory_plug(HotplugHandler *hotplug_dev,
> > +                             DeviceState *dev, Error **errp)
> > +{
> > +    VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
> > +
> > +    pc_dimm_plug(PC_DIMM(dev), MACHINE(vms), NULL);
> > +
> > +}
> > +
> > +static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
> > +                                            DeviceState *dev,
> Error **errp)
> > +{
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +        virt_memory_pre_plug(hotplug_dev, dev, errp);
> > +    }
> > +}
> > +
> >  static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> >                                          DeviceState *dev, Error
> **errp)
> >  {
> > @@ -1817,12 +1847,23 @@ static void
> virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
> >                                       SYS_BUS_DEVICE(dev));
> >          }
> >      }
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +        virt_memory_plug(hotplug_dev, dev, errp);
> > +    }
> > +}
> > +
> > +static void virt_machine_device_unplug_request_cb(HotplugHandler
> *hotplug_dev,
> > +                                          DeviceState *dev, Error
> **errp)
> > +{
> > +    error_setg(errp, "device unplug request for unsupported device"
> > +               " type: %s", object_get_typename(OBJECT(dev)));
> >  }
> >
> >  static HotplugHandler *virt_machine_get_hotplug_handler(MachineState
> *machine,
> >
> DeviceState *dev)
> >  {
> > -    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE) ||
> > +       (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM))) {
> >          return HOTPLUG_HANDLER(machine);
> >      }
> >
> > @@ -1886,7 +1927,9 @@ static void virt_machine_class_init(ObjectClass
> *oc, void *data)
> >      mc->kvm_type = virt_kvm_type;
> >      assert(!mc->get_hotplug_handler);
> >      mc->get_hotplug_handler = virt_machine_get_hotplug_handler;
> > +    hc->pre_plug = virt_machine_device_pre_plug_cb;
> >      hc->plug = virt_machine_device_plug_cb;
> > +    hc->unplug_request = virt_machine_device_unplug_request_cb;
> >  }
> >
> >  static void virt_instance_init(Object *obj)