Re: [PATCH 2/6] memory: Introduce address_space_create()

[Peter Maydell <peter.maydell@linaro.org>]

On Thu, 19 Aug 2021 at 15:20, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>
> Introduce address_space_create(). In is similar to
> address_space_init() but returns a pointer to a heap
> allocated  AddressSpace.
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  include/exec/memory.h | 14 ++++++++++++++
>  softmmu/memory.c      | 10 ++++++++++
>  2 files changed, 24 insertions(+)
>
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index c3d417d317f..b353a48c25f 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -2418,6 +2418,20 @@ MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
>   */
>  void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name);
>
> +/**
> + * address_space_create: Create and initializes an address space
> + *
> + * @root: a #MemoryRegion that routes addresses for the address space
> + * @name: an address space name.  The name is only used for debugging
> + *        output.
> + *
> + * Returns pointer to initialized #AddressSpace.
> + *
> + * The caller is responsible for releasing the pointer returned
> + * with address_space_destroy() after use.
> + */
> +AddressSpace *address_space_create(MemoryRegion *root, const char *name);
> +

I'm not really a fan of this as an API -- almost always I think
devices would do better to have an AddressSpace foo field in
their device struct and call address_space_init() on that.
Hiding the heap allocation inside this function makes it harder
to notice it during code review, I think.

thanks
-- PMM