Re: [Qemu-devel] [RFC PATCH v2.1 05/12] qdev: hotplug: Introduce HotplugHandler.pre_plug() callback

[David Gibson]

On Fri, Apr 01, 2016 at 12:38:28PM +0200, Paolo Bonzini wrote:
> 
> 
> On 01/04/2016 05:30, David Gibson wrote:
> > On Thu, Mar 31, 2016 at 02:09:14PM +0530, Bharata B Rao wrote:
> >> From: Igor Mammedov <address@hidden>
> >>
> >> pre_plug callback is to be called before device.realize() is executed.
> >> This would allow to check/set device's properties from HotplugHandler.
> >>
> >> Signed-off-by: Igor Mammedov <address@hidden>
> >> Signed-off-by: Bharata B Rao <address@hidden>
> > 
> > Reviewed-by: David Gibson <address@hidden>
> > 
> > It would be really nice to get some opinion on this from Andreas or
> > Paolo.
> 
> Certainly okay for me, Igor did all of the HotplugHandler design and
> work.

Ok, good to hear.  Thanks.

> 
> Paolo
> 
> >> ---
> >>  hw/core/hotplug.c    | 11 +++++++++++
> >>  hw/core/qdev.c       |  9 ++++++++-
> >>  include/hw/hotplug.h | 14 +++++++++++++-
> >>  3 files changed, 32 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/hw/core/hotplug.c b/hw/core/hotplug.c
> >> index 645cfca..17ac986 100644
> >> --- a/hw/core/hotplug.c
> >> +++ b/hw/core/hotplug.c
> >> @@ -13,6 +13,17 @@
> >>  #include "hw/hotplug.h"
> >>  #include "qemu/module.h"
> >>  
> >> +void hotplug_handler_pre_plug(HotplugHandler *plug_handler,
> >> +                              DeviceState *plugged_dev,
> >> +                              Error **errp)
> >> +{
> >> +    HotplugHandlerClass *hdc = HOTPLUG_HANDLER_GET_CLASS(plug_handler);
> >> +
> >> +    if (hdc->pre_plug) {
> >> +        hdc->pre_plug(plug_handler, plugged_dev, errp);
> >> +    }
> >> +}
> >> +
> >>  void hotplug_handler_plug(HotplugHandler *plug_handler,
> >>                            DeviceState *plugged_dev,
> >>                            Error **errp)
> >> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> >> index db41aa1..a0b3aad 100644
> >> --- a/hw/core/qdev.c
> >> +++ b/hw/core/qdev.c
> >> @@ -1062,6 +1062,14 @@ static void device_set_realized(Object *obj, bool 
> >> value, Error **errp)
> >>              g_free(name);
> >>          }
> >>  
> >> +        hotplug_ctrl = qdev_get_hotplug_handler(dev);
> >> +        if (hotplug_ctrl) {
> >> +            hotplug_handler_pre_plug(hotplug_ctrl, dev, &local_err);
> >> +            if (local_err != NULL) {
> >> +                goto fail;
> >> +            }
> >> +        }
> >> +
> >>          if (dc->realize) {
> >>              dc->realize(dev, &local_err);
> >>          }
> >> @@ -1072,7 +1080,6 @@ static void device_set_realized(Object *obj, bool 
> >> value, Error **errp)
> >>  
> >>          DEVICE_LISTENER_CALL(realize, Forward, dev);
> >>  
> >> -        hotplug_ctrl = qdev_get_hotplug_handler(dev);
> >>          if (hotplug_ctrl) {
> >>              hotplug_handler_plug(hotplug_ctrl, dev, &local_err);
> >>          }
> >> diff --git a/include/hw/hotplug.h b/include/hw/hotplug.h
> >> index 2db025d..50d84e9 100644
> >> --- a/include/hw/hotplug.h
> >> +++ b/include/hw/hotplug.h
> >> @@ -46,7 +46,8 @@ typedef void (*hotplug_fn)(HotplugHandler *plug_handler,
> >>   * hardware (un)plug functions.
> >>   *
> >>   * @parent: Opaque parent interface.
> >> - * @plug: plug callback.
> >> + * @pre_plug: pre plug callback called at start of device.realize(true)
> >> + * @plug: plug callback called at end of device.realize(true).
> >>   * @unplug_request: unplug request callback.
> >>   *                  Used as a means to initiate device unplug for devices 
> >> that
> >>   *                  require asynchronous unplug handling.
> >> @@ -59,6 +60,7 @@ typedef struct HotplugHandlerClass {
> >>      InterfaceClass parent;
> >>  
> >>      /* <public> */
> >> +    hotplug_fn pre_plug;
> >>      hotplug_fn plug;
> >>      hotplug_fn unplug_request;
> >>      hotplug_fn unplug;
> >> @@ -74,6 +76,16 @@ void hotplug_handler_plug(HotplugHandler *plug_handler,
> >>                            Error **errp);
> >>  
> >>  /**
> >> + * hotplug_handler_pre_plug:
> >> + *
> >> + * Call #HotplugHandlerClass.pre_plug callback of @plug_handler.
> >> + */
> >> +void hotplug_handler_pre_plug(HotplugHandler *plug_handler,
> >> +                              DeviceState *plugged_dev,
> >> +                              Error **errp);
> >> +
> >> +
> >> +/**
> >>   * hotplug_handler_unplug_request:
> >>   *
> >>   * Calls #HotplugHandlerClass.unplug_request callback of @plug_handler.
> > 
> 




-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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