Re: [Qemu-devel] [PATCH v4 10/20] hw/arm/virt-acpi-build: Generate RSDT table

["Alex Bennée" <alex.bennee@linaro.org>]

Shannon Zhao <zhaoshenglong@huawei.com> writes:

> From: Shannon Zhao <shannon.zhao@linaro.org>
>
> RSDT points to other tables FADT, MADT, GTDT.
>
> Signed-off-by: Shannon Zhao <zhaoshenglong@huawei.com>
> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
> ---
>  hw/arm/virt-acpi-build.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index a7aba75..85e84b1 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -176,6 +176,30 @@ static void acpi_dsdt_add_virtio(Aml *scope, const hwaddr *mmio_addrs,
>      }
>  }
>  
> +/* RSDT */
> +static void
> +build_rsdt(GArray *table_data, GArray *linker, GArray *table_offsets)
> +{
> +    AcpiRsdtDescriptorRev1 *rsdt;
> +    size_t rsdt_len;
> +    int i;
> +
> +    rsdt_len = sizeof(*rsdt) + sizeof(uint32_t) * table_offsets->len;

You should use explicit brackets to be unambiguous:

       rsdt_len = sizeof(*rsdt) + (sizeof(uint32_t) * table_offsets->len);

> +    rsdt = acpi_data_push(table_data, rsdt_len);
> +    memcpy(rsdt->table_offset_entry, table_offsets->data,
> +           sizeof(uint32_t) * table_offsets->len);

Or perhaps split the sizes:

   const int table_data_len = (sizeof(uint32_t) * table_offsets->len);

   rsdt_len = sizeof(*rsdt) + table_data_len;
   rsdt = acpi_data_push(table_data, rsdt_len);
   memcpy(rsdt->table_offset_entry, table_offsets->data, table_data_len)

Maybe?

> +    for (i = 0; i < table_offsets->len; ++i) {
> +        /* rsdt->table_offset_entry to be filled by Guest linker */
> +        bios_linker_loader_add_pointer(linker,
> +                                       ACPI_BUILD_TABLE_FILE,
> +                                       ACPI_BUILD_TABLE_FILE,
> +                                       table_data, &rsdt->table_offset_entry[i],
> +                                       sizeof(uint32_t));

Why are these pointers always 32 bit? Can they ever be 64 bit?

> +    }
> +    build_header(linker, table_data,
> +                 (void *)rsdt, "RSDT", rsdt_len, 1);
> +}
> +
>  /* GTDT */
>  static void
>  build_gtdt(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
> @@ -348,6 +372,9 @@ void virt_acpi_build(VirtGuestInfo *guest_info, AcpiBuildTables *tables)
>      acpi_add_table(table_offsets, tables_blob);
>      build_gtdt(tables_blob, tables->linker, guest_info);
>  
> +    /* RSDT is pointed to by RSDP */
> +    build_rsdt(tables_blob, tables->linker, table_offsets);
> +
>      /* Cleanup memory that's no longer used. */
>      g_array_free(table_offsets, true);
>  }

-- 
Alex Bennée