Re: [Qemu-devel] [PATCH v7 10/17] hw/arm/virt: Add memory hotplug framework

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 20 Feb 2019 23:39:56 +0100
Eric Auger <eric.auger@redhat.com> wrote:

> This patch adds the the memory hot-plug/hot-unplug infrastructure
> in machvirt. It is still not enabled as no device memory is allocated.
> 
> Signed-off-by: Eric Auger <eric.auger@redhat.com>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> Signed-off-by: Kwangwoo Lee <kwangwoo.lee@sk.com>

with nit below fixed

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> 
> ---
> v4 -> v5:
> - change in pc_dimm_pre_plug signature
> - CONFIG_MEM_HOTPLUG replaced by CONFIG_MEM_DEVICE and CONFIG_DIMM
> 
> v3 -> v4:
> - check the memory device is not hotplugged
> 
> v2 -> v3:
> - change in pc_dimm_plug()'s signature
> - add pc_dimm_pre_plug call
> 
> v1 -> v2:
> - s/virt_dimm_plug|unplug/virt_memory_plug|unplug
> - s/pc_dimm_memory_plug/pc_dimm_plug
> - reworded title and commit message
> - added pre_plug cb
> - don't handle get_memory_region failure anymore
> ---
>  default-configs/arm-softmmu.mak |  2 ++
>  hw/arm/virt.c                   | 64 ++++++++++++++++++++++++++++++++-
>  2 files changed, 65 insertions(+), 1 deletion(-)
> 
> diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
> index 734ca721e9..0a78421f72 100644
> --- a/default-configs/arm-softmmu.mak
> +++ b/default-configs/arm-softmmu.mak
> @@ -163,3 +163,5 @@ CONFIG_PCI_EXPRESS_DESIGNWARE=y
>  CONFIG_STRONGARM=y
>  CONFIG_HIGHBANK=y
>  CONFIG_MUSICPAL=y
> +CONFIG_MEM_DEVICE=y
> +CONFIG_DIMM=y
> diff --git a/hw/arm/virt.c b/hw/arm/virt.c
> index 5b656f9db5..470ca0ce2d 100644
> --- a/hw/arm/virt.c
> +++ b/hw/arm/virt.c
> @@ -60,6 +60,8 @@
>  #include "standard-headers/linux/input.h"
>  #include "hw/arm/smmuv3.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, \
> @@ -1804,6 +1806,49 @@ 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)
> +{
> +    const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
> +
> +    if (dev->hotplugged) {
> +        error_setg(errp, "memory hotplug is not supported");
> +    }
> +
> +    if (is_nvdimm) {
> +        error_setg(errp, "nvdimm 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);
> +    Error *local_err = NULL;
> +
> +    pc_dimm_plug(PC_DIMM(dev), MACHINE(vms), &local_err);
> +
> +    error_propagate(errp, local_err);
> +}
> +
> +static void virt_memory_unplug(HotplugHandler *hotplug_dev,
> +                               DeviceState *dev, Error **errp)
> +{
> +    pc_dimm_unplug(PC_DIMM(dev), MACHINE(hotplug_dev));
> +    object_unparent(OBJECT(dev));
> +}
> +
> +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)
>  {
> @@ -1815,12 +1860,27 @@ 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);
wrong indent

> +    }
> +}
> +
> +static void virt_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
> +                                          DeviceState *dev, Error **errp)
> +{
> +    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +        virt_memory_unplug(hotplug_dev, dev, errp);
> +    } else {
> +        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);
>      }
>  
> @@ -1884,7 +1944,9 @@ 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 = virt_machine_device_unplug_cb;
>  }
>  
>  static void virt_instance_init(Object *obj)