[Qemu-devel] [PATCH 1/1] spapr: Correct reference count on spapr-cpu-core

[Qemu-devel] [PATCH 1/1] spapr: Correct reference count on spapr-cpu-core

[Sam Bobroff]

spapr_init_cpus() currently creates spapr-cpu-core objects via
object_new() and setting their realized property to true. This leaves
their reference count at two, because object_new() adds an initial
reference and the realization attaches them to a default parent object
which also increments the reference count.

This causes a problem if one of these cores is hot unplugged: no
delete event is generated for it because it's reference count doesn't
reach zero when it is detached from it's parent.

Correct this by adding a call to object_unref() in spapr_init_cpus().

Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
---
 hw/ppc/spapr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 0d032a1ad0..fbb00f0c56 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2502,6 +2502,8 @@ static void spapr_init_cpus(sPAPRMachineState *spapr)
             object_property_set_int(core, core_id, CPU_CORE_PROP_CORE_ID,
                                     &error_fatal);
             object_property_set_bool(core, true, "realized", &error_fatal);
+
+            object_unref(core);
         }
     }
 }
-- 
2.16.1.74.g9b0b1f47b

Re: [Qemu-devel] [PATCH 1/1] spapr: Correct reference count on spapr-cpu-core

[David Gibson]

[-- Attachment #1: Type: text/plain, Size: 1541 bytes --]

On Thu, Aug 30, 2018 at 03:54:40PM +1000, Sam Bobroff wrote:
11;rgb:ffff/ffff/ffff> spapr_init_cpus() currently creates spapr-cpu-core objects via
> object_new() and setting their realized property to true. This leaves
> their reference count at two, because object_new() adds an initial
> reference and the realization attaches them to a default parent object
> which also increments the reference count.
> 
> This causes a problem if one of these cores is hot unplugged: no
> delete event is generated for it because it's reference count doesn't
> reach zero when it is detached from it's parent.
> 
> Correct this by adding a call to object_unref() in spapr_init_cpus().
> 
> Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>

Applied to ppc-for-3.1.

> ---
>  hw/ppc/spapr.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 0d032a1ad0..fbb00f0c56 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2502,6 +2502,8 @@ static void spapr_init_cpus(sPAPRMachineState *spapr)
>              object_property_set_int(core, core_id, CPU_CORE_PROP_CORE_ID,
>                                      &error_fatal);
>              object_property_set_bool(core, true, "realized", &error_fatal);
> +
> +            object_unref(core);
>          }
>      }
>  }

-- 
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

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]