acpi: madt: arm/x86: use acpi_table_begin()/acpi_table_end() instead of build_header()

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>
Message-Id: <20210924122802.1455362-22-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

2 files changed, 22 insertions, 16 deletions

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);
 }