Re: [PATCH v3 21/35] acpi: madt: arm/x86: use acpi_table_begin()/acpi_table_end() instead of build_header()

[Eric Auger <eauger@redhat.com>]

On 9/7/21 4:48 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>
> ---
> v3:
>   * s/acpi_init_table|acpi_table_composed/acpi_table_begin|acpi_table_end/
> 
> CC: marcel.apfelbaum@gmail.com
> CC: shannon.zhaosl@gmail.com
> CC: peter.maydell@linaro.org
> CC: qemu-arm@nongnu.org
> CC: drjones@redhat.com
> CC: eauger@redhat.com
> ---
>  include/hw/acpi/acpi-defs.h |  9 ---------
>  hw/arm/virt-acpi-build.c    | 19 +++++++++++--------
>  hw/i386/acpi-common.c       | 19 +++++++++++--------
>  3 files changed, 22 insertions(+), 25 deletions(-)
> 
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index c4f0a202e8..c7fa5caa06 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -176,15 +176,6 @@ typedef struct AcpiFacsDescriptorRev1 AcpiFacsDescriptorRev1;
>  #define ACPI_DUAL_PIC                0
>  #define ACPI_MULTIPLE_APIC           1
>  
> -/* Master MADT */
> -
> -struct AcpiMultipleApicTable {
> -    ACPI_TABLE_HEADER_DEF     /* ACPI common table header */
> -    uint32_t local_apic_address;     /* Physical address of local APIC */
> -    uint32_t flags;
> -} QEMU_PACKED;
> -typedef struct AcpiMultipleApicTable AcpiMultipleApicTable;
> -
>  /* Values for Type in APIC sub-headers */
>  
>  #define ACPI_APIC_PROCESSOR          0
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 6ba02cf281..e3bdcd44e8 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -567,19 +567,26 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>                   vms->oem_table_id);
>  }
>  
> -/* MADT */
> +/*
> + * ACPI spec, Revision 5.0
> + * 5.2.12 Multiple APIC Description Table (MADT)
> + */
>  static void
>  build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  {
>      VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
> -    int madt_start = table_data->len;
>      const MemMapEntry *memmap = vms->memmap;
>      const int *irqmap = vms->irqmap;
>      AcpiMadtGenericDistributor *gicd;
>      AcpiMadtGenericMsiFrame *gic_msi;
>      int i;
> +    AcpiTable table = { .sig = "APIC", .rev = 3, .oem_id = vms->oem_id,
> +                        .oem_table_id = vms->oem_table_id };
>  
> -    acpi_data_push(table_data, sizeof(AcpiMultipleApicTable));
> +    acpi_table_begin(&table, table_data);
> +    /* Local Interrupt Controller Address */
> +    build_append_int_noprefix(table_data, 0, 4);
> +    build_append_int_noprefix(table_data, 0, 4); /* Flags */
>  
>      gicd = acpi_data_push(table_data, sizeof *gicd);
>      gicd->type = ACPI_APIC_GENERIC_DISTRIBUTOR;
> @@ -650,11 +657,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>          gic_msi->spi_count = cpu_to_le16(NUM_GICV2M_SPIS);
>          gic_msi->spi_base = cpu_to_le16(irqmap[VIRT_GIC_V2M] + ARM_SPI_BASE);
>      }
> -
> -    build_header(linker, table_data,
> -                 (void *)(table_data->data + madt_start), "APIC",
> -                 table_data->len - madt_start, 3, vms->oem_id,
> -                 vms->oem_table_id);
> +    acpi_table_end(linker, &table);
>  }
>  
>  /* FADT */
> diff --git a/hw/i386/acpi-common.c b/hw/i386/acpi-common.c
> index 1f5947fcf9..a0cde1d874 100644
> --- a/hw/i386/acpi-common.c
> +++ b/hw/i386/acpi-common.c
> @@ -71,24 +71,29 @@ void pc_madt_cpu_entry(AcpiDeviceIf *adev, int uid,
>      }
>  }
>  
> +/*
> + * ACPI spec, Revision 1.0b
> + * 5.2.8 Multiple APIC Description Table
> + */
>  void acpi_build_madt(GArray *table_data, BIOSLinker *linker,
>                       X86MachineState *x86ms, AcpiDeviceIf *adev,
>                       const char *oem_id, const char *oem_table_id)
>  {
>      MachineClass *mc = MACHINE_GET_CLASS(x86ms);
>      const CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(MACHINE(x86ms));
> -    int madt_start = table_data->len;
>      AcpiDeviceIfClass *adevc = ACPI_DEVICE_IF_GET_CLASS(adev);
>      bool x2apic_mode = false;
>  
> -    AcpiMultipleApicTable *madt;
>      AcpiMadtIoApic *io_apic;
>      AcpiMadtIntsrcovr *intsrcovr;
>      int i;
> +    AcpiTable table = { .sig = "APIC", .rev = 1, .oem_id = oem_id,
> +                        .oem_table_id = oem_table_id };
>  
> -    madt = acpi_data_push(table_data, sizeof *madt);
> -    madt->local_apic_address = cpu_to_le32(APIC_DEFAULT_ADDRESS);
> -    madt->flags = cpu_to_le32(1);
> +    acpi_table_begin(&table, table_data);
> +    /* Local APIC Address */
> +    build_append_int_noprefix(table_data, APIC_DEFAULT_ADDRESS, 4);
> +    build_append_int_noprefix(table_data, 1 /* PCAT_COMPAT */, 4); /* Flags */
>  
>      for (i = 0; i < apic_ids->len; i++) {
>          adevc->madt_cpu(adev, i, apic_ids, table_data);
> @@ -156,8 +161,6 @@ void acpi_build_madt(GArray *table_data, BIOSLinker *linker,
>          local_nmi->lint         = 1; /* ACPI_LINT1 */
>      }
>  
> -    build_header(linker, table_data,
> -                 (void *)(table_data->data + madt_start), "APIC",
> -                 table_data->len - madt_start, 1, oem_id, oem_table_id);
> +    acpi_table_end(linker, &table);
>  }
>  
> 
Reviewed-by: Eric Auger <eric.auger@redhat.com>

Eric