diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 54a8b28a58..d04e4acbd9 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -929,9 +929,11 @@ static void create_fw_cfg(const VirtBoardInfo *vbi, AddressSpace *as)
 {
     hwaddr base = vbi->memmap[VIRT_FW_CFG].base;
     hwaddr size = vbi->memmap[VIRT_FW_CFG].size;
+    FWCfgState *fw_cfg;
     char *nodename;
 
-    fw_cfg_init_mem_wide(base + 8, base, 8, base + 16, as);
+    fw_cfg = fw_cfg_init_mem_wide(base + 8, base, 8, base + 16, as);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
 
     nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
     qemu_fdt_add_subnode(vbi->fdt, nodename);
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index c227eadbfd..e8757b4c62 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -744,6 +744,7 @@ static FWCfgState *bochs_bios_init(AddressSpace *as, PCMachineState *pcms)
     int i, j;
 
     fw_cfg = fw_cfg_init_io_dma(FW_CFG_IO_BASE, FW_CFG_IO_BASE + 4, as);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
 
     /* FW_CFG_MAX_CPUS is a bit confusing/problematic on x86:
      *
@@ -1341,6 +1342,7 @@ void xen_load_linux(PCMachineState *pcms)
     assert(MACHINE(pcms)->kernel_filename != NULL);
 
     fw_cfg = fw_cfg_init_io(FW_CFG_IO_BASE);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
     rom_set_fw(fw_cfg);
 
     load_linux(pcms, fw_cfg);
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 1f0c3e9910..3ebecb2260 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -884,7 +884,6 @@ static void fw_cfg_init1(DeviceState *dev)
     fw_cfg_add_bytes(s, FW_CFG_SIGNATURE, (char *)"QEMU", 4);
     fw_cfg_add_bytes(s, FW_CFG_UUID, &qemu_uuid, 16);
     fw_cfg_add_i16(s, FW_CFG_NOGRAPHIC, (uint16_t)!machine->enable_graphics);
-    fw_cfg_add_i16(s, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
     fw_cfg_add_i16(s, FW_CFG_BOOT_MENU, (uint16_t)boot_menu);
     fw_cfg_bootsplash(s);
     fw_cfg_reboot(s);
diff --git a/hw/ppc/mac_newworld.c b/hw/ppc/mac_newworld.c
index 7d2510658d..2bfdb643df 100644
--- a/hw/ppc/mac_newworld.c
+++ b/hw/ppc/mac_newworld.c
@@ -466,6 +466,7 @@ static void ppc_core99_init(MachineState *machine)
     /* No PCI init: the BIOS will do it */
 
     fw_cfg = fw_cfg_init_mem(CFG_ADDR, CFG_ADDR + 2);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MACHINE_ID, machine_arch);
diff --git a/hw/ppc/mac_oldworld.c b/hw/ppc/mac_oldworld.c
index 447948746b..56282c5bc6 100644
--- a/hw/ppc/mac_oldworld.c
+++ b/hw/ppc/mac_oldworld.c
@@ -319,6 +319,7 @@ static void ppc_heathrow_init(MachineState *machine)
     /* No PCI init: the BIOS will do it */
 
     fw_cfg = fw_cfg_init_mem(CFG_ADDR, CFG_ADDR + 2);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MACHINE_ID, ARCH_HEATHROW);
diff --git a/hw/sparc/sun4m.c b/hw/sparc/sun4m.c
index 6224288ac3..f5b6efddf8 100644
--- a/hw/sparc/sun4m.c
+++ b/hw/sparc/sun4m.c
@@ -1033,6 +1033,7 @@ static void sun4m_hw_init(const struct sun4m_hwdef *hwdef,
                  hwdef->ecc_version);
 
     fw_cfg = fw_cfg_init_mem(CFG_ADDR, CFG_ADDR + 2);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MACHINE_ID, hwdef->machine_id);
diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c
index 271d8bc592..466331535b 100644
--- a/hw/sparc64/sun4u.c
+++ b/hw/sparc64/sun4u.c
@@ -855,6 +855,7 @@ static void sun4uv_init(MemoryRegion *address_space_mem,
                            (uint8_t *)&nd_table[0].macaddr);
 
     fw_cfg = fw_cfg_init_io(BIOS_CFG_IOPORT);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
     fw_cfg_add_i16(fw_cfg, FW_CFG_MACHINE_ID, hwdef->machine_id);