Re: [PATCH 4/6] hw/dma: Replace alloc() + address_space_init() by address_space_create()

[Peter Maydell]

On Thu, 19 Aug 2021 at 15:21, Philippe Mathieu-Daudé <philmd@redhat.com> wrote:
>
> Replace g_malloc0() + address_space_init() by address_space_create().
> Release the resource in DeviceUnrealize().
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  hw/dma/xlnx-zdma.c    | 15 +++++++++------
>  hw/dma/xlnx_csu_dma.c |  9 ++-------
>  2 files changed, 11 insertions(+), 13 deletions(-)
>
> diff --git a/hw/dma/xlnx-zdma.c b/hw/dma/xlnx-zdma.c
> index fa38a556341..9f6b3fa47c6 100644
> --- a/hw/dma/xlnx-zdma.c
> +++ b/hw/dma/xlnx-zdma.c
> @@ -777,15 +777,17 @@ static void zdma_realize(DeviceState *dev, Error **errp)
>          };
>      }
>
> -    if (s->dma_mr) {
> -        s->dma_as = g_malloc0(sizeof(AddressSpace));
> -        address_space_init(s->dma_as, s->dma_mr, NULL);
> -    } else {
> -        s->dma_as = &address_space_memory;
> -    }
> +    s->dma_as = address_space_create(s->dma_mr ?: get_system_memory(), NULL);
>      s->attr = MEMTXATTRS_UNSPECIFIED;
>  }

Why are these devices doing a heap allocation rather than
having an AddressSpace whatever field in their device struct ?

thanks
-- PMM