Re: [Qemu-devel] [PATCH] hw/ppc: Use object_initialize_child for correct reference counting

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 2/21/19 12:24 PM, Thomas Huth wrote:
> Both functions, object_initialize() and object_property_add_child() increase
> the reference counter of the new object, so one of the references has to be
> dropped afterwards to get the reference counting right. Otherwise the child
> object will not be properly cleaned up when the parent gets destroyed.
> Thus let's use now object_initialize_child() instead to get the reference
> counting here right.
> 
> Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>  hw/ppc/pnv.c     | 12 ++++++------
>  hw/ppc/pnv_psi.c |  4 ++--
>  hw/ppc/spapr.c   |  6 +++---
>  3 files changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/hw/ppc/pnv.c b/hw/ppc/pnv.c
> index da54086..9e03e9c 100644
> --- a/hw/ppc/pnv.c
> +++ b/hw/ppc/pnv.c
> @@ -736,18 +736,18 @@ static void pnv_chip_power8_instance_init(Object *obj)
>  {
>      Pnv8Chip *chip8 = PNV8_CHIP(obj);
>  
> -    object_initialize(&chip8->psi, sizeof(chip8->psi), TYPE_PNV_PSI);
> -    object_property_add_child(obj, "psi", OBJECT(&chip8->psi), NULL);
> +    object_initialize_child(obj, "psi",  &chip8->psi, sizeof(chip8->psi),
> +                            TYPE_PNV_PSI, &error_abort, NULL);
>      object_property_add_const_link(OBJECT(&chip8->psi), "xics",
>                                     OBJECT(qdev_get_machine()), &error_abort);
>  
> -    object_initialize(&chip8->lpc, sizeof(chip8->lpc), TYPE_PNV_LPC);
> -    object_property_add_child(obj, "lpc", OBJECT(&chip8->lpc), NULL);
> +    object_initialize_child(obj, "lpc",  &chip8->lpc, sizeof(chip8->lpc),
> +                            TYPE_PNV_LPC, &error_abort, NULL);
>      object_property_add_const_link(OBJECT(&chip8->lpc), "psi",
>                                     OBJECT(&chip8->psi), &error_abort);
>  
> -    object_initialize(&chip8->occ, sizeof(chip8->occ), TYPE_PNV_OCC);
> -    object_property_add_child(obj, "occ", OBJECT(&chip8->occ), NULL);
> +    object_initialize_child(obj, "occ",  &chip8->occ, sizeof(chip8->occ),
> +                            TYPE_PNV_OCC, &error_abort, NULL);
>      object_property_add_const_link(OBJECT(&chip8->occ), "psi",
>                                     OBJECT(&chip8->psi), &error_abort);
>  }
> diff --git a/hw/ppc/pnv_psi.c b/hw/ppc/pnv_psi.c
> index 8ced095..44bc0cb 100644
> --- a/hw/ppc/pnv_psi.c
> +++ b/hw/ppc/pnv_psi.c
> @@ -444,8 +444,8 @@ static void pnv_psi_init(Object *obj)
>  {
>      PnvPsi *psi = PNV_PSI(obj);
>  
> -    object_initialize(&psi->ics, sizeof(psi->ics), TYPE_ICS_SIMPLE);
> -    object_property_add_child(obj, "ics-psi", OBJECT(&psi->ics), NULL);
> +    object_initialize_child(obj, "ics-psi",  &psi->ics, sizeof(psi->ics),
> +                            TYPE_ICS_SIMPLE, &error_abort, NULL);
>  }
>  
>  static const uint8_t irq_to_xivr[] = {
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index abf9ebc..6c58dca 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1696,9 +1696,9 @@ static void spapr_create_nvram(sPAPRMachineState *spapr)
>  
>  static void spapr_rtc_create(sPAPRMachineState *spapr)
>  {
> -    object_initialize(&spapr->rtc, sizeof(spapr->rtc), TYPE_SPAPR_RTC);
> -    object_property_add_child(OBJECT(spapr), "rtc", OBJECT(&spapr->rtc),
> -                              &error_fatal);
> +    object_initialize_child(OBJECT(spapr), "rtc",
> +                            &spapr->rtc, sizeof(spapr->rtc), TYPE_SPAPR_RTC,
> +                            &error_fatal, NULL);
>      object_property_set_bool(OBJECT(&spapr->rtc), true, "realized",
>                                &error_fatal);
>      object_property_add_alias(OBJECT(spapr), "rtc-time", OBJECT(&spapr->rtc),
> 

What about intc/spapr_xive.c?

-- >8 --
@@ -244,13 +244,15 @@ static void spapr_xive_instance_init(Obj
 {
     sPAPRXive *xive = SPAPR_XIVE(obj);

-    object_initialize(&xive->source, sizeof(xive->source),
TYPE_XIVE_SOURCE);
-    object_property_add_child(obj, "source", OBJECT(&xive->source), NULL);
+    object_initialize_child(obj, "source", &xive->source,
+                            sizeof(xive->source), TYPE_XIVE_SOURCE,
+                            &error_abort, NULL);

-    object_initialize(&xive->end_source, sizeof(xive->end_source),
-                      TYPE_XIVE_END_SOURCE);
-    object_property_add_child(obj, "end_source", OBJECT(&xive->end_source),
-                              NULL);
+    object_initialize_child(obj, "end_source", &xive->end_source,
+                            sizeof(xive->end_source), TYPE_XIVE_END_SOURCE,
+                            &error_abort, NULL);
 }
---