Virt: ACPI: fix qemu assert due to re-assigned table data address

acpi_data_push uses g_array_set_size to resize the memory size. If there
is no enough contiguous memory, the address will be changed. If we use
the old value, it will assert.
qemu-kvm: hw/acpi/bios-linker-loader.c:214: bios_linker_loader_add_checksum:
Assertion `start_offset < file->blob->len' failed.`

This issue only happens in building SRAT table now but here we unify the
pattern for other tables as well to avoid possible issues in the future.

Signed-off-by: Zhaoshenglong <zhaoshenglong@huawei.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/arm/virt-acpi-build.c

@@ -453,6 +453,7 @@ build_spcr(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     AcpiSerialPortConsoleRedirection *spcr;
     const MemMapEntry *uart_memmap = &vms->memmap[VIRT_UART];
     int irq = vms->irqmap[VIRT_UART] + ARM_SPI_BASE;
+    int spcr_start = table_data->len;
 
     spcr = acpi_data_push(table_data, sizeof(*spcr));
 
@@ -476,8 +477,8 @@ build_spcr(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     spcr->pci_device_id = 0xffff;  /* PCI Device ID: not a PCI device */
     spcr->pci_vendor_id = 0xffff;  /* PCI Vendor ID: not a PCI device */
 
-    build_header(linker, table_data, (void *)spcr, "SPCR", sizeof(*spcr), 2,
-                 NULL, NULL);
+    build_header(linker, table_data, (void *)(table_data->data + spcr_start),
+                 "SPCR", table_data->len - spcr_start, 2, NULL, NULL);
 }
 
 static void
@@ -512,8 +513,8 @@ build_srat(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         mem_base += numa_info[i].node_mem;
     }
 
-    build_header(linker, table_data, (void *)srat, "SRAT",
-                 table_data->len - srat_start, 3, NULL, NULL);
+    build_header(linker, table_data, (void *)(table_data->data + srat_start),
+                 "SRAT", table_data->len - srat_start, 3, NULL, NULL);
 }
 
 static void
@@ -522,6 +523,7 @@ build_mcfg(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     AcpiTableMcfg *mcfg;
     const MemMapEntry *memmap = vms->memmap;
     int len = sizeof(*mcfg) + sizeof(mcfg->allocation[0]);
+    int mcfg_start = table_data->len;
 
     mcfg = acpi_data_push(table_data, len);
     mcfg->allocation[0].address = cpu_to_le64(memmap[VIRT_PCIE_ECAM].base);
@@ -532,7 +534,8 @@ build_mcfg(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     mcfg->allocation[0].end_bus_number = (memmap[VIRT_PCIE_ECAM].size
                                           / PCIE_MMCFG_SIZE_MIN) - 1;
 
-    build_header(linker, table_data, (void *)mcfg, "MCFG", len, 1, NULL, NULL);
+    build_header(linker, table_data, (void *)(table_data->data + mcfg_start),
+                 "MCFG", table_data->len - mcfg_start, 1, NULL, NULL);
 }
 
 /* GTDT */
@@ -651,6 +654,7 @@ build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
 static void build_fadt(GArray *table_data, BIOSLinker *linker,
                        VirtMachineState *vms, unsigned dsdt_tbl_offset)
 {
+    int fadt_start = table_data->len;
     AcpiFadtDescriptorRev5_1 *fadt = acpi_data_push(table_data, sizeof(*fadt));
     unsigned xdsdt_entry_offset = (char *)&fadt->x_dsdt - table_data->data;
     uint16_t bootflags;
@@ -681,8 +685,8 @@ static void build_fadt(GArray *table_data, BIOSLinker *linker,
         ACPI_BUILD_TABLE_FILE, xdsdt_entry_offset, sizeof(fadt->x_dsdt),
         ACPI_BUILD_TABLE_FILE, dsdt_tbl_offset);
 
-    build_header(linker, table_data,
-                 (void *)fadt, "FACP", sizeof(*fadt), 5, NULL, NULL);
+    build_header(linker, table_data, (void *)(table_data->data + fadt_start),
+                 "FACP", table_data->len - fadt_start, 5, NULL, NULL);
 }
 
 /* DSDT */