[PATCH v4 15/35] acpi: build_tpm_tcpa: use acpi_table_begin()/acpi_table_end() instead of build_header()

[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.

While at it switch to build_append_int_noprefix() to build
table entries (which also removes some manual offset
calculations).

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
---
v2:
  * fix assert when starting QEMU with TPM 1.2
      Stefan Berger <stefanb@linux.ibm.com>
v3:
 * fix invalid checksum, by putting acpi_table_composed()
   after pointer patching
 * s/acpi_init_table|acpi_table_composed/acpi_table_begin|acpi_table_end/

CC: stefanb@linux.vnet.ibm.com
---
 include/hw/acpi/acpi-defs.h | 14 --------------
 hw/i386/acpi-build.c        | 38 ++++++++++++++++++++++---------------
 2 files changed, 23 insertions(+), 29 deletions(-)

diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index 4d8f8b34b0..3b42b138f0 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -418,20 +418,6 @@ struct AcpiSratProcessorGiccAffinity {
 
 typedef struct AcpiSratProcessorGiccAffinity AcpiSratProcessorGiccAffinity;
 
-/*
- * TCPA Description Table
- *
- * Following Level 00, Rev 00.37 of specs:
- * http://www.trustedcomputinggroup.org/resources/tcg_acpi_specification
- */
-struct Acpi20Tcpa {
-    ACPI_TABLE_HEADER_DEF                    /* ACPI common table header */
-    uint16_t platform_class;
-    uint32_t log_area_minimum_length;
-    uint64_t log_area_start_address;
-} QEMU_PACKED;
-typedef struct Acpi20Tcpa Acpi20Tcpa;
-
 /* DMAR - DMA Remapping table r2.2 */
 struct AcpiTableDmar {
     ACPI_TABLE_HEADER_DEF
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 1587fe5a20..9fa6d7665b 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1878,31 +1878,39 @@ build_hpet(GArray *table_data, BIOSLinker *linker, const char *oem_id,
 }
 
 #ifdef CONFIG_TPM
+/*
+ * TCPA Description Table
+ *
+ * Following Level 00, Rev 00.37 of specs:
+ * http://www.trustedcomputinggroup.org/resources/tcg_acpi_specification
+ * 7.1.2 ACPI Table Layout
+ */
 static void
 build_tpm_tcpa(GArray *table_data, BIOSLinker *linker, GArray *tcpalog,
                const char *oem_id, const char *oem_table_id)
 {
-    int tcpa_start = table_data->len;
-    Acpi20Tcpa *tcpa = acpi_data_push(table_data, sizeof *tcpa);
-    unsigned log_addr_size = sizeof(tcpa->log_area_start_address);
-    unsigned log_addr_offset =
-        (char *)&tcpa->log_area_start_address - table_data->data;
+    unsigned log_addr_offset;
+    AcpiTable table = { .sig = "TCPA", .rev = 2,
+                        .oem_id = oem_id, .oem_table_id = oem_table_id };
 
-    tcpa->platform_class = cpu_to_le16(TPM_TCPA_ACPI_CLASS_CLIENT);
-    tcpa->log_area_minimum_length = cpu_to_le32(TPM_LOG_AREA_MINIMUM_SIZE);
-    acpi_data_push(tcpalog, le32_to_cpu(tcpa->log_area_minimum_length));
+    acpi_table_begin(&table, table_data);
+    /* Platform Class */
+    build_append_int_noprefix(table_data, TPM_TCPA_ACPI_CLASS_CLIENT, 2);
+    /* Log Area Minimum Length (LAML) */
+    build_append_int_noprefix(table_data, TPM_LOG_AREA_MINIMUM_SIZE, 4);
+    /* Log Area Start Address (LASA) */
+    log_addr_offset = table_data->len;
+    build_append_int_noprefix(table_data, 0, 8);
 
+    /* allocate/reserve space for TPM log area */
+    acpi_data_push(tcpalog, TPM_LOG_AREA_MINIMUM_SIZE);
     bios_linker_loader_alloc(linker, ACPI_BUILD_TPMLOG_FILE, tcpalog, 1,
                              false /* high memory */);
-
     /* log area start address to be filled by Guest linker */
-    bios_linker_loader_add_pointer(linker,
-        ACPI_BUILD_TABLE_FILE, log_addr_offset, log_addr_size,
-        ACPI_BUILD_TPMLOG_FILE, 0);
+    bios_linker_loader_add_pointer(linker, ACPI_BUILD_TABLE_FILE,
+        log_addr_offset, 8, ACPI_BUILD_TPMLOG_FILE, 0);
 
-    build_header(linker, table_data,
-                 (void *)(table_data->data + tcpa_start),
-                 "TCPA", sizeof(*tcpa), 2, oem_id, oem_table_id);
+    acpi_table_end(linker, &table);
 }
 #endif
 
-- 
2.27.0