[PULL 40/57] acpi: build_dsdt_microvm: use acpi_table_begin()/acpi_table_end() instead of build_header()

["Michael S. Tsirkin" <mst@redhat.com>]

From: Igor Mammedov <imammedo@redhat.com>

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: <20210924122802.1455362-27-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/i386/acpi-microvm.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/hw/i386/acpi-microvm.c b/hw/i386/acpi-microvm.c
index 1a0f77b911..196d318499 100644
--- a/hw/i386/acpi-microvm.c
+++ b/hw/i386/acpi-microvm.c
@@ -113,16 +113,16 @@ build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
     Aml *dsdt, *sb_scope, *scope, *pkg;
     bool ambiguous;
     Object *isabus;
+    AcpiTable table = { .sig = "DSDT", .rev = 2, .oem_id = x86ms->oem_id,
+                        .oem_table_id = x86ms->oem_table_id };
 
     isabus = object_resolve_path_type("", TYPE_ISA_BUS, &ambiguous);
     assert(isabus);
     assert(!ambiguous);
 
+    acpi_table_begin(&table, table_data);
     dsdt = init_aml_allocator();
 
-    /* Reserve space for header */
-    acpi_data_push(dsdt->buf, sizeof(AcpiTableHeader));
-
     sb_scope = aml_scope("_SB");
     fw_cfg_add_acpi_dsdt(sb_scope, x86ms->fw_cfg);
     isa_build_aml(ISA_BUS(isabus), sb_scope);
@@ -144,11 +144,10 @@ build_dsdt_microvm(GArray *table_data, BIOSLinker *linker,
     aml_append(scope, aml_name_decl("_S5", pkg));
     aml_append(dsdt, scope);
 
-    /* copy AML table into ACPI tables blob and patch header there */
+    /* copy AML bytecode 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, x86ms->oem_id, x86ms->oem_table_id);
+
+    acpi_table_end(linker, &table);
     free_aml_allocator();
 }
 
-- 
MST