Re: [Qemu-devel] [PATCH for-2.10 2/3] Revert "qdev: Free QemuOpts when the QOM path goes away"

[Greg Kurz]

On Wed, 26 Jul 2017 20:30:54 -0500
Michael Roth <address@hidden> wrote:

> This reverts commit abed886ec60cf239a03515cf0b30fb11fa964c44.
> 
> This patch originally addressed an issue where a DEVICE_DELETED
> event could be emitted (in device_unparent()) before a Device's
> QemuOpts were cleaned up (in device_finalize()), leading to a
> "duplicate ID" error if management attempted to immediately add
> a device with the same ID in response to the DEVICE_DELETED event.
> 
> An alternative will be implemented in a subsequent patch where we
> defer the DEVICE_DELETED event until device_finalize(), which would
> also prevent the race, so we revert the original fix in preparation.
> 

Do you really need to revert abed886ec60cf239a03515cf0b30fb11fa964c44 ?

IIUC, the purpose of this series is to fix/workaround the VFIO cleanup issue.
Even if it also relates to when we emit DEVICE_DELETED, it isn't exactly the
same problem here, is it ?

> Signed-off-by: Michael Roth <address@hidden>
> ---
>  hw/core/qdev.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
> index a64b35c..08c4061 100644
> --- a/hw/core/qdev.c
> +++ b/hw/core/qdev.c
> @@ -1067,6 +1067,7 @@ static void device_finalize(Object *obj)
>      NamedGPIOList *ngl, *next;
>  
>      DeviceState *dev = DEVICE(obj);
> +    qemu_opts_del(dev->opts);
>  
>      QLIST_FOREACH_SAFE(ngl, &dev->gpios, node, next) {
>          QLIST_REMOVE(ngl, node);
> @@ -1116,9 +1117,6 @@ static void device_unparent(Object *obj)
>          g_free(dev->canonical_path);
>          dev->canonical_path = NULL;
>      }
> -
> -    qemu_opts_del(dev->opts);
> -    dev->opts = NULL;
>  }
>  
>  static void device_class_init(ObjectClass *class, void *data)

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