Ping Philippe & Markus,
Do you have furthur comment on such private realize()? ;-)
Thanks,
Zhao
On Thu, Feb 01, 2024 at 11:25:56AM +0800, Zhao Liu wrote:
> Date: Thu, 1 Feb 2024 11:25:56 +0800
> From: Zhao Liu <zhao1....@linux.intel.com>
> Subject: Re: [PATCH] hw/intc: Handle the error of
> IOAPICCommonClass.realize()
>
> Hi Philippe,
>
> On Wed, Jan 31, 2024 at 05:48:24PM +0100, Philippe Mathieu-Daud? wrote:
> > Date: Wed, 31 Jan 2024 17:48:24 +0100
> > From: Philippe Mathieu-Daud? <phi...@linaro.org>
> > Subject: Re: [PATCH] hw/intc: Handle the error of
> > IOAPICCommonClass.realize()
> >
> > Hi Zhao,
> >
> > On 31/1/24 15:29, Zhao Liu wrote:
> > > From: Zhao Liu <zhao1....@intel.com>
> > >
> > > IOAPICCommonClass implements its own private realize(), and this private
> > > realize() allows error.
> > >
> > > Therefore, return directly if IOAPICCommonClass.realize() meets error.
> > >
> > > Signed-off-by: Zhao Liu <zhao1....@intel.com>
> > > ---
> > > hw/intc/ioapic_common.c | 3 +++
> > > 1 file changed, 3 insertions(+)
> > >
> > > diff --git a/hw/intc/ioapic_common.c b/hw/intc/ioapic_common.c
> > > index cb9bf6214608..3772863377c2 100644
> > > --- a/hw/intc/ioapic_common.c
> > > +++ b/hw/intc/ioapic_common.c
> > > @@ -162,6 +162,9 @@ static void ioapic_common_realize(DeviceState *dev,
> > > Error **errp)
> > > info = IOAPIC_COMMON_GET_CLASS(s);
> > > info->realize(dev, errp);
> > > + if (*errp) {
> > > + return;
> > > + }
> >
> > Could be clearer to deviate from DeviceRealize and let the
> > handler return a boolean:
> >
> > -- >8 --
> > diff --git a/hw/intc/ioapic_internal.h b/hw/intc/ioapic_internal.h
> > index 37b8565539..9664bb3e00 100644
> > --- a/hw/intc/ioapic_internal.h
> > +++ b/hw/intc/ioapic_internal.h
> > @@ -92,3 +92,3 @@ struct IOAPICCommonClass {
> >
> > - DeviceRealize realize;
> > + bool (*realize)(DeviceState *dev, Error **errp);
>
> What about I change the name of this interface?
>
> Maybe ioapic_realize(), to distinguish it from DeviceClass.realize().
>
> > DeviceUnrealize unrealize;
>
> Additionally, if I change the pattern of realize(), should I also avoid
> the DeviceUnrealize macro for symmetry's sake and just declare a similar
> function pointer as you said?
>
> Further, do you think it's necessary to introduce InternalRealize and
> InternalUnrealize macros for qdev to wrap these special realize/unrealize
> to differentiate them from normal DeviceRealize/DeviceUnrealize?
>
> Because I found that this pattern of realize() (i.e. registering the
> realize() of the child class in the parent class instead of DeviceClass,
> and then calling the registered realize() in parent realize()) is also
> widely used in many cases:
>
> * xen_block_realize()
> * virtser_port_device_realize()
> * x86_iommu_realize()
> * virtio_input_device_realize()
> * apic_common_realize()
> * pc_dimm_realize()
> * virtio_device_realize()
> ...
>
> I'm not quite sure if this is a generic way to use it, although it looks
> like it could easily be confused with DeviceClass.realize().
>
> > diff --git a/hw/i386/kvm/ioapic.c b/hw/i386/kvm/ioapic.c
> > index 409d0c8c76..96747ef2b8 100644
> > --- a/hw/i386/kvm/ioapic.c
> > +++ b/hw/i386/kvm/ioapic.c
> > @@ -121,3 +121,3 @@ static void kvm_ioapic_set_irq(void *opaque, int irq,
> > int level)
> >
> > -static void kvm_ioapic_realize(DeviceState *dev, Error **errp)
> > +static bool kvm_ioapic_realize(DeviceState *dev, Error **errp)
> > {
> > @@ -133,2 +133,4 @@ static void kvm_ioapic_realize(DeviceState *dev, Error
> > **errp)
> > qdev_init_gpio_in(dev, kvm_ioapic_set_irq, IOAPIC_NUM_PINS);
> > +
> > + return true;
> > }
> > diff --git a/hw/intc/ioapic_common.c b/hw/intc/ioapic_common.c
> > index cb9bf62146..beab65be04 100644
> > --- a/hw/intc/ioapic_common.c
> > +++ b/hw/intc/ioapic_common.c
> > @@ -163,3 +163,5 @@ static void ioapic_common_realize(DeviceState *dev,
> > Error **errp)
> > info = IOAPIC_COMMON_GET_CLASS(s);
> > - info->realize(dev, errp);
> > + if (!info->realize(dev, errp)) {
> > + return;
> > + }
> >
> > ---
> >
> > What do you think?
>
> I'm OK with the change here, but not sure if the return of private
> realize() should be changed elsewhere as well.
>
> Thanks,
> Zhao
>
>
