Re: [Qemu-devel] [RESEND PATCH v3 1/8] acpi, piix4: Add memory hot unplug support for piix4.

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 27 Aug 2014 16:08:32 +0800
Tang Chen <tangchen@cn.fujitsu.com> wrote:

> From: Hu Tao <hutao@cn.fujitsu.com>
> 
> Implement acpi_memory_unplug_cb(), sending an sci to guest to trigger
> memory hot-remove, and call it in piix4_device_unplug_cb().
> 
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
> ---
>  hw/acpi/memory_hotplug.c         | 25 +++++++++++++++++++++++++
>  hw/acpi/piix4.c                  |  3 +++
>  include/hw/acpi/memory_hotplug.h |  2 ++
>  3 files changed, 30 insertions(+)
> 
> diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
> index ed39241..c310b44 100644
> --- a/hw/acpi/memory_hotplug.c
> +++ b/hw/acpi/memory_hotplug.c
> @@ -195,6 +195,31 @@ void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
>      return;
>  }
>  
> +void acpi_memory_unplug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
> +                           DeviceState *dev, Error **errp)
> +{
> +    Error *local_err = NULL;
> +    int slot = object_property_get_int(OBJECT(dev), "slot", &local_err);
might be worth to use PC_DIMM_SLOT_PROP here, and while at it
do the same to acpi_memory_plug_cb() as well in separate patch.

> +
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return;
> +    }
> +
> +    if (slot >= mem_st->dev_count) {
> +        char *dev_path = object_get_canonical_path(OBJECT(dev));
> +        error_setg(errp, "acpi_memory_plug_cb: "
> +                   "device [%s] returned invalid memory slot[%d]",
> +                   dev_path, slot);
> +        g_free(dev_path);
> +        return;
> +    }
move 3 above blocks into separate function to reduce code duplication
with acpi_memory_plug_cb(), perhaps something like following:

MemStatus *
acpi_memory_get_slot_status_descriptor(MemHotplugState *mem_st,
                                       DeviceState *dev, Error **errp);

>+
place here also missing removal signaling for selected mdev,
perhaps it's due to wrong patch ordering

> +    /* do ACPI magic */
> +    ar->gpe.sts[0] |= ACPI_MEMORY_HOTPLUG_STATUS;
> +    acpi_update_sci(ar, irq);
worth to make this block a separate function and reuse in
acpi_memory_plug_cb()

> +}
> +
>  static const VMStateDescription vmstate_memhp_sts = {
>      .name = "memory hotplug device state",
>      .version_id = 1,
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index b72b34e..c1d5187 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -362,6 +362,9 @@ static void piix4_device_unplug_cb(HotplugHandler *hotplug_dev,
>      if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
>          acpi_pcihp_device_unplug_cb(&s->ar, s->irq, &s->acpi_pci_hotplug, dev,
>                                      errp);
> +    } else if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
> +        acpi_memory_unplug_cb(&s->ar, s->irq, &s->acpi_memory_hotplug, dev,
> +                              errp);
>      } else {
>          error_setg(errp, "acpi: device unplug request for not supported device"
>                     " type: %s", object_get_typename(OBJECT(dev)));
> diff --git a/include/hw/acpi/memory_hotplug.h b/include/hw/acpi/memory_hotplug.h
> index 7bbf8a0..fc6b868 100644
> --- a/include/hw/acpi/memory_hotplug.h
> +++ b/include/hw/acpi/memory_hotplug.h
> @@ -28,6 +28,8 @@ void acpi_memory_hotplug_init(MemoryRegion *as, Object *owner,
>  
>  void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
>                           DeviceState *dev, Error **errp);
> +void acpi_memory_unplug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
> +                           DeviceState *dev, Error **errp);
>  
>  extern const VMStateDescription vmstate_memory_hotplug;
>  #define VMSTATE_MEMORY_HOTPLUG(memhp, state) \