Re: [Qemu-devel] [PATCH v2 04/11] memory: add getter for owner

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2013-06-28 18:58, Paolo Bonzini wrote:
> Whenever memory regions are accessed outside the BQL, they need to be
> preserved against hot-unplug.  MemoryRegions actually do not have their
> own reference count; they piggyback on a QOM object, their "owner".
> The owner is set at creation time, and there is a function to retrieve
> the owner.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  include/exec/memory.h | 7 +++++++
>  memory.c              | 6 ++++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index be3d39f..1ad9c19 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -380,6 +380,13 @@ void memory_region_init_iommu(MemoryRegion *mr,
>  void memory_region_destroy(MemoryRegion *mr);
>  
>  /**
> + * memory_region_owner: get a memory region's owner.
> + *
> + * @mr: the memory region being queried.
> + */
> +struct Object *memory_region_owner(MemoryRegion *mr);
> +
> +/**
>   * memory_region_size: get a memory region's size.
>   *
>   * @mr: the memory region being queried.
> diff --git a/memory.c b/memory.c
> index 6250bec1..4d396c3 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -738,6 +738,7 @@ void memory_region_init(MemoryRegion *mr,
>      mr->owner = owner;
>      mr->iommu_ops = NULL;
>      mr->parent = NULL;
> +    mr->owner = NULL;
>      mr->size = int128_make64(size);
>      if (size == UINT64_MAX) {
>          mr->size = int128_2_64();
> @@ -1011,6 +1012,11 @@ void memory_region_destroy(MemoryRegion *mr)
>      g_free(mr->ioeventfds);
>  }
>  
> +Object *memory_region_owner(MemoryRegion *mr)
> +{
> +    return mr->owner;
> +}
> +
>  uint64_t memory_region_size(MemoryRegion *mr)
>  {
>      if (int128_eq(mr->size, int128_2_64())) {
> 

OK, fine... and who is using this? ;)

Also, as this is trivial and the structure publicly known anyway, I'd go
for a static inline function instead.

Jan

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