Re: [PATCH v2 27/35] acpi: arm: virt: build_dsdt: use acpi_init_table()/acpi_table_composed() instead of build_header()

[Eric Auger <eauger@redhat.com>]

On 7/8/21 5:46 PM, Igor Mammedov wrote:
> it replaces error-prone pointer arithmetic for build_header() API,
> with 2 calls to start and finish table creation,
> which hides offsets magic from API user.
> 
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric
> ---
> CC: peter.maydell@linaro.org
> CC: shannon.zhaosl@gmail.com
> CC: qemu-arm@nongnu.org
> CC: drjones@redhat.com
> ---
>  hw/arm/virt-acpi-build.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index dd8011a670..d15e67a39b 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -636,10 +636,11 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>      MachineState *ms = MACHINE(vms);
>      const MemMapEntry *memmap = vms->memmap;
>      const int *irqmap = vms->irqmap;
> +    AcpiTable table = { .sig = "DSDT", .rev = 2, .oem_id = vms->oem_id,
> +                        .oem_table_id = vms->oem_table_id };
>  
> +    acpi_init_table(&table, table_data);
>      dsdt = init_aml_allocator();
> -    /* Reserve space for header */
> -    acpi_data_push(dsdt->buf, sizeof(AcpiTableHeader));
>  
>      /* When booting the VM with UEFI, UEFI takes ownership of the RTC hardware.
>       * While UEFI can use libfdt to disable the RTC device node in the DTB that
> @@ -686,12 +687,10 @@ build_dsdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  
>      aml_append(dsdt, scope);
>  
> -    /* copy AML table into ACPI tables blob and patch header there */
> +    /* copy AML table into ACPI tables blob */
>      g_array_append_vals(table_data, dsdt->buf->data, dsdt->buf->len);
> -    build_header(linker, table_data,
> -        (void *)(table_data->data + table_data->len - dsdt->buf->len),
> -                 "DSDT", dsdt->buf->len, 2, vms->oem_id,
> -                 vms->oem_table_id);
> +
> +    acpi_table_composed(linker, &table);
>      free_aml_allocator();
>  }
>  
>