Re: [Qemu-devel] [PATCH v2 14/36] qdev: HotplugHandler: rename unplug callback to unplug_request

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Sep 26, 2014 at 09:28:19AM +0000, Igor Mammedov wrote:
> 'HotplugHandler.unplug' callback is currently used as async
> call to issue unplug request for device that implements it.
> Renaming 'unplug' callback to 'unplug_request' should help to
> avoid confusion about what callback does and would allow to
> introduce 'unplug' callback that would perform actual device
> removal when guest is ready for it.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

> ---
> Patch is prompted by reviewing https://patchwork.ozlabs.org/patch/383372/
> 
> Dedicated 'unplug' callback could be used by bus-less pc-dimm
> device. It would allow to call HotplugHandler.unplug callback
> from ACPI code when guest calls _EJ0 method and execute board
> specific code (PCMachine) to unmap pc-dimm from guest's address
> space and perform necessary cleanup. The same applies to CPU
> unplug.
> ---
>  hw/acpi/piix4.c                |  6 +++---
>  hw/core/hotplug.c              | 10 +++++-----
>  hw/core/qdev.c                 |  3 ++-
>  hw/isa/lpc_ich9.c              |  6 +++---
>  hw/pci-bridge/pci_bridge_dev.c |  2 +-
>  hw/pci/pcie.c                  |  4 ++--
>  hw/pci/pcie_port.c             |  2 +-
>  hw/pci/shpc.c                  |  4 ++--
>  include/hw/hotplug.h           | 16 +++++++++-------
>  include/hw/pci/pcie.h          |  4 ++--
>  include/hw/pci/shpc.h          |  4 ++--
>  11 files changed, 32 insertions(+), 29 deletions(-)
> 
> diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
> index b72b34e..0bfa814 100644
> --- a/hw/acpi/piix4.c
> +++ b/hw/acpi/piix4.c
> @@ -354,8 +354,8 @@ static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
>      }
>  }
>  
> -static void piix4_device_unplug_cb(HotplugHandler *hotplug_dev,
> -                                   DeviceState *dev, Error **errp)
> +static void piix4_device_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                           DeviceState *dev, Error **errp)
>  {
>      PIIX4PMState *s = PIIX4_PM(hotplug_dev);
>  
> @@ -615,7 +615,7 @@ static void piix4_pm_class_init(ObjectClass *klass, void *data)
>      dc->cannot_instantiate_with_device_add_yet = true;
>      dc->hotpluggable = false;
>      hc->plug = piix4_device_plug_cb;
> -    hc->unplug = piix4_device_unplug_cb;
> +    hc->unplug_request = piix4_device_unplug_request_cb;
>      adevc->ospm_status = piix4_ospm_status;
>  }
>  
> diff --git a/hw/core/hotplug.c b/hw/core/hotplug.c
> index 5573d9d..2ec4736 100644
> --- a/hw/core/hotplug.c
> +++ b/hw/core/hotplug.c
> @@ -23,14 +23,14 @@ void hotplug_handler_plug(HotplugHandler *plug_handler,
>      }
>  }
>  
> -void hotplug_handler_unplug(HotplugHandler *plug_handler,
> -                            DeviceState *plugged_dev,
> -                            Error **errp)
> +void hotplug_handler_unplug_request(HotplugHandler *plug_handler,
> +                                    DeviceState *plugged_dev,
> +                                    Error **errp)
>  {
>      HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
>  
> -    if (hdc->unplug) {
> -        hdc->unplug(plug_handler, plugged_dev, errp);
> +    if (hdc->unplug_request) {
> +        hdc->unplug_request(plug_handler, plugged_dev, errp);
>      }
>  }
>  
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index 5e5b963..c98e5db 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -227,7 +227,8 @@ void qdev_unplug(DeviceState *dev, Error **errp)
>      qdev_hot_removed = true;
>  
>      if (dev->parent_bus && dev->parent_bus->hotplug_handler) {
> -        hotplug_handler_unplug(dev->parent_bus->hotplug_handler, dev, errp);
> +        hotplug_handler_unplug_request(dev->parent_bus->hotplug_handler,
> +                                       dev, errp);
>      } else {
>          assert(dc->unplug != NULL);
>          if (dc->unplug(dev) < 0) { /* legacy handler */
> diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
> index 177023b..530b074 100644
> --- a/hw/isa/lpc_ich9.c
> +++ b/hw/isa/lpc_ich9.c
> @@ -607,8 +607,8 @@ static void ich9_device_plug_cb(HotplugHandler *hotplug_dev,
>      ich9_pm_device_plug_cb(&lpc->pm, dev, errp);
>  }
>  
> -static void ich9_device_unplug_cb(HotplugHandler *hotplug_dev,
> -                                  DeviceState *dev, Error **errp)
> +static void ich9_device_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                          DeviceState *dev, Error **errp)
>  {
>      error_setg(errp, "acpi: device unplug request for not supported device"
>                 " type: %s", object_get_typename(OBJECT(dev)));
> @@ -676,7 +676,7 @@ static void ich9_lpc_class_init(ObjectClass *klass, void *data)
>       */
>      dc->cannot_instantiate_with_device_add_yet = true;
>      hc->plug = ich9_device_plug_cb;
> -    hc->unplug = ich9_device_unplug_cb;
> +    hc->unplug_request = ich9_device_unplug_request_cb;
>      adevc->ospm_status = ich9_pm_ospm_status;
>  }
>  
> diff --git a/hw/pci-bridge/pci_bridge_dev.c b/hw/pci-bridge/pci_bridge_dev.c
> index 92799d0..252ea5e 100644
> --- a/hw/pci-bridge/pci_bridge_dev.c
> +++ b/hw/pci-bridge/pci_bridge_dev.c
> @@ -150,7 +150,7 @@ static void pci_bridge_dev_class_init(ObjectClass *klass, void *data)
>      dc->vmsd = &pci_bridge_dev_vmstate;
>      set_bit(DEVICE_CATEGORY_BRIDGE, dc->categories);
>      hc->plug = shpc_device_hotplug_cb;
> -    hc->unplug = shpc_device_hot_unplug_cb;
> +    hc->unplug_request = shpc_device_hot_unplug_request_cb;
>  }
>  
>  static const TypeInfo pci_bridge_dev_info = {
> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
> index 1babddf..b64a004 100644
> --- a/hw/pci/pcie.c
> +++ b/hw/pci/pcie.c
> @@ -262,8 +262,8 @@ void pcie_cap_slot_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
>                          PCI_EXP_HP_EV_PDC | PCI_EXP_HP_EV_ABP);
>  }
>  
> -void pcie_cap_slot_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
> -                                 Error **errp)
> +void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                         DeviceState *dev, Error **errp)
>  {
>      uint8_t *exp_cap;
>  
> diff --git a/hw/pci/pcie_port.c b/hw/pci/pcie_port.c
> index fa24877..40ca8d5 100644
> --- a/hw/pci/pcie_port.c
> +++ b/hw/pci/pcie_port.c
> @@ -154,7 +154,7 @@ static void pcie_slot_class_init(ObjectClass *oc, void *data)
>  
>      dc->props = pcie_slot_props;
>      hc->plug = pcie_cap_slot_hotplug_cb;
> -    hc->unplug = pcie_cap_slot_hot_unplug_cb;
> +    hc->unplug_request = pcie_cap_slot_hot_unplug_request_cb;
>  }
>  
>  static const TypeInfo pcie_slot_type_info = {
> diff --git a/hw/pci/shpc.c b/hw/pci/shpc.c
> index 1fcb8c4..65b2f51 100644
> --- a/hw/pci/shpc.c
> +++ b/hw/pci/shpc.c
> @@ -549,8 +549,8 @@ void shpc_device_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
>      shpc_interrupt_update(pci_hotplug_dev);
>  }
>  
> -void shpc_device_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
> -                               Error **errp)
> +void shpc_device_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                       DeviceState *dev, Error **errp)
>  {
>      Error *local_err = NULL;
>      PCIDevice *pci_hotplug_dev = PCI_DEVICE(hotplug_dev);
> diff --git a/include/hw/hotplug.h b/include/hw/hotplug.h
> index a6533cb..e397d08 100644
> --- a/include/hw/hotplug.h
> +++ b/include/hw/hotplug.h
> @@ -47,7 +47,9 @@ typedef void (*hotplug_fn)(HotplugHandler *plug_handler,
>   *
>   * @parent: Opaque parent interface.
>   * @plug: plug callback.
> - * @unplug: unplug callback.
> + * @unplug_request: unplug request callback.
> + *                  Used as a means to initiate device unplug for devices that
> + *                  require asynchronous unplug handling.
>   */
>  typedef struct HotplugHandlerClass {
>      /* <private> */
> @@ -55,7 +57,7 @@ typedef struct HotplugHandlerClass {
>  
>      /* <public> */
>      hotplug_fn plug;
> -    hotplug_fn unplug;
> +    hotplug_fn unplug_request;
>  } HotplugHandlerClass;
>  
>  /**
> @@ -68,11 +70,11 @@ void hotplug_handler_plug(HotplugHandler *plug_handler,
>                            Error **errp);
>  
>  /**
> - * hotplug_handler_unplug:
> + * hotplug_handler_unplug_request:
>   *
> - * Call #HotplugHandlerClass.unplug callback of @plug_handler.
> + * Calls #HotplugHandlerClass.unplug_request callback of @plug_handler.
>   */
> -void hotplug_handler_unplug(HotplugHandler *plug_handler,
> -                            DeviceState *plugged_dev,
> -                            Error **errp);
> +void hotplug_handler_unplug_request(HotplugHandler *plug_handler,
> +                                    DeviceState *plugged_dev,
> +                                    Error **errp);
>  #endif
> diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
> index d139d58..b48a7a2 100644
> --- a/include/hw/pci/pcie.h
> +++ b/include/hw/pci/pcie.h
> @@ -128,6 +128,6 @@ extern const VMStateDescription vmstate_pcie_device;
>  
>  void pcie_cap_slot_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
>                                Error **errp);
> -void pcie_cap_slot_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
> -                                 Error **errp);
> +void pcie_cap_slot_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                         DeviceState *dev, Error **errp);
>  #endif /* QEMU_PCIE_H */
> diff --git a/include/hw/pci/shpc.h b/include/hw/pci/shpc.h
> index eef1a1a..025bc5b 100644
> --- a/include/hw/pci/shpc.h
> +++ b/include/hw/pci/shpc.h
> @@ -46,8 +46,8 @@ void shpc_cap_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int len);
>  
>  void shpc_device_hotplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
>                              Error **errp);
> -void shpc_device_hot_unplug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
> -                               Error **errp);
> +void shpc_device_hot_unplug_request_cb(HotplugHandler *hotplug_dev,
> +                                       DeviceState *dev, Error **errp);
>  
>  extern VMStateInfo shpc_vmstate_info;
>  #define SHPC_VMSTATE(_field, _type) \
> -- 
> 1.8.3.1