acpi: pci: use build_append_foo() API to construct MCFG

build_append_foo() API doesn't need explicit endianness conversions
which eliminates a source of errors and it makes build_mcfg() look like
declarative definition of MCFG table in ACPI spec, which makes it easy
to review.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Suggested-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>

v3:
   * add some comment on the Configuration Space base address allocation
     structure
v2:
   * miss the reserved[8] of MCFG in last version, add it back
   * drop SOBs and make sure bios-tables-test all OK
Message-Id: <20190521062836.6541-3-richardw.yang@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/acpi/pci.c

@@ -30,17 +30,32 @@
 
 void build_mcfg(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info)
 {
-    AcpiTableMcfg *mcfg;
-    int len = sizeof(*mcfg) + sizeof(mcfg->allocation[0]);
-
-    mcfg = acpi_data_push(table_data, len);
-    mcfg->allocation[0].address = cpu_to_le64(info->base);
-
-    /* Only a single allocation so no need to play with segments */
-    mcfg->allocation[0].pci_segment = cpu_to_le16(0);
-    mcfg->allocation[0].start_bus_number = 0;
-    mcfg->allocation[0].end_bus_number = PCIE_MMCFG_BUS(info->size - 1);
-
-    build_header(linker, table_data, (void *)mcfg, "MCFG", len, 1, NULL, NULL);
+    int mcfg_start = table_data->len;
+
+    /*
+     * PCI Firmware Specification, Revision 3.0
+     * 4.1.2 MCFG Table Description.
+     */
+    acpi_data_push(table_data, sizeof(AcpiTableHeader));
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 8);
+
+    /*
+     * Memory Mapped Enhanced Configuration Space Base Address Allocation
+     * Structure
+     */
+    /* Base address, processor-relative */
+    build_append_int_noprefix(table_data, info->base, 8);
+    /* PCI segment group number */
+    build_append_int_noprefix(table_data, 0, 2);
+    /* Starting PCI Bus number */
+    build_append_int_noprefix(table_data, 0, 1);
+    /* Final PCI Bus number */
+    build_append_int_noprefix(table_data, PCIE_MMCFG_BUS(info->size - 1), 1);
+    /* Reserved */
+    build_append_int_noprefix(table_data, 0, 4);
+
+    build_header(linker, table_data, (void *)(table_data->data + mcfg_start),
+                 "MCFG", table_data->len - mcfg_start, 1, NULL, NULL);
 }
 

include/hw/acpi/acpi-defs.h

@@ -449,24 +449,6 @@ struct AcpiSratProcessorGiccAffinity {
 
 typedef struct AcpiSratProcessorGiccAffinity AcpiSratProcessorGiccAffinity;
 
-/* PCI fw r3.0 MCFG table. */
-/* Subtable */
-struct AcpiMcfgAllocation {
-    uint64_t address;                /* Base address, processor-relative */
-    uint16_t pci_segment;            /* PCI segment group number */
-    uint8_t start_bus_number;       /* Starting PCI Bus number */
-    uint8_t end_bus_number;         /* Final PCI Bus number */
-    uint32_t reserved;
-} QEMU_PACKED;
-typedef struct AcpiMcfgAllocation AcpiMcfgAllocation;
-
-struct AcpiTableMcfg {
-    ACPI_TABLE_HEADER_DEF;
-    uint8_t reserved[8];
-    AcpiMcfgAllocation allocation[0];
-} QEMU_PACKED;
-typedef struct AcpiTableMcfg AcpiTableMcfg;
-
 /*
  * TCPA Description Table
  *