Re: [Qemu-devel] [PATCH v5 4/8] hw/arm/virt: Add memory hotplug framework

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

Hi Eric,

> -----Original Message-----
> From: Auger Eric [mailto:eric.auger@redhat.com]
> Sent: 18 June 2019 13:42
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;
> qemu-devel@nongnu.org; qemu-arm@nongnu.org; imammedo@redhat.com
> Cc: peter.maydell@linaro.org; shannon.zhaosl@gmail.com;
> sameo@linux.intel.com; sebastien.boeuf@intel.com; xuwei (O)
> <xuwei5@huawei.com>; lersek@redhat.com; ard.biesheuvel@linaro.org;
> Linuxarm <linuxarm@huawei.com>
> Subject: Re: [PATCH v5 4/8] hw/arm/virt: Add memory hotplug framework
> 
> Hi Shameer,
> 
> On 5/22/19 6:22 PM, Shameer Kolothum wrote:
> > From: Eric Auger <eric.auger@redhat.com>
> >
> > This patch adds the memory hot-plug/hot-unplug infrastructure in
> > machvirt. The device memory is not yet exposed to the Guest either
> > through DT or ACPI and hence both cold/hot plug of memory is
> > explicitly disabled for now.
> >
> > Signed-off-by: Eric Auger <eric.auger@redhat.com>
> > Signed-off-by: Kwangwoo Lee <kwangwoo.lee@sk.com>
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> > ---
> >  hw/arm/Kconfig |  2 ++
> >  hw/arm/virt.c  | 51
> > +++++++++++++++++++++++++++++++++++++++++++++++++-
> >  2 files changed, 52 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig index
> > af8cffde9c..6ef22439b5 100644
> > --- a/hw/arm/Kconfig
> > +++ b/hw/arm/Kconfig
> > @@ -19,6 +19,8 @@ config ARM_VIRT
> >      select PLATFORM_BUS
> >      select SMBIOS
> >      select VIRTIO_MMIO
> small conflict to be resolved here after addition of "select ACPI_PCI".

Ok. I will address that in next revision.

Thanks,
Shameer

> > +    select MEM_DEVICE
> > +    select DIMM
> >
> >  config CHEETAH
> >      bool
> > diff --git a/hw/arm/virt.c b/hw/arm/virt.c index
> > 5331ab71e2..3df8c389ff 100644
> > --- a/hw/arm/virt.c
> > +++ b/hw/arm/virt.c
> > @@ -62,6 +62,8 @@
> >  #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,
> > \ @@ -1862,6 +1864,40 @@ 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) {
> > +
> > +    /*
> > +     * The device memory is not yet exposed to the Guest either through>
> +     * DT or ACPI and hence both cold/hot plug of memory is explicitly
> > +     * disabled for now.
> > +     */
> > +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> > +        error_setg(errp, "memory cold/hot plug is not yet supported");
> > +        return;
> > +    }
> > +
> > +    pc_dimm_pre_plug(PC_DIMM(dev), MACHINE(hotplug_dev), NULL,
> errp);
> > +}
> > +
> > +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)  { @@ -1873,12 +1909,23 @@ 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);
> >      }
> >
> > @@ -1942,7 +1989,9 @@ 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)
> >
> Thanks
> 
> Eric