fw_cfg: allow building without other devices

The microvm machine type uses fw_cfg but lacks SMBIOS and ACPI.  Do not
include the files if the symbol is not present in QEMU and remove
dependencies on machine-specific files.

Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/i386/fw_cfg.c

@@ -22,6 +22,9 @@
 #include "hw/nvram/fw_cfg.h"
 #include "e820_memory_layout.h"
 #include "kvm_i386.h"
+#include "config-devices.h"
+
+struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX};
 
 const char *fw_cfg_arch_key_name(uint16_t key)
 {
@@ -46,6 +49,7 @@ const char *fw_cfg_arch_key_name(uint16_t key)
 
 void fw_cfg_build_smbios(MachineState *ms, FWCfgState *fw_cfg)
 {
+#ifdef CONFIG_SMBIOS
     uint8_t *smbios_tables, *smbios_anchor;
     size_t smbios_tables_len, smbios_anchor_len;
     struct smbios_phys_mem_area *mem_array;
@@ -83,6 +87,7 @@ void fw_cfg_build_smbios(MachineState *ms, FWCfgState *fw_cfg)
         fw_cfg_add_file(fw_cfg, "etc/smbios/smbios-anchor",
                         smbios_anchor, smbios_anchor_len);
     }
+#endif
 }
 
 FWCfgState *fw_cfg_arch_create(MachineState *ms,
@@ -114,8 +119,10 @@ FWCfgState *fw_cfg_arch_create(MachineState *ms,
      */
     fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, apic_id_limit);
     fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
+#ifdef CONFIG_ACPI
     fw_cfg_add_bytes(fw_cfg, FW_CFG_ACPI_TABLES,
                      acpi_tables, acpi_tables_len);
+#endif
     fw_cfg_add_i32(fw_cfg, FW_CFG_IRQ0_OVERRIDE, kvm_allows_irq0_override());
 
     fw_cfg_add_bytes(fw_cfg, FW_CFG_E820_TABLE,

hw/i386/pc.c

@@ -101,8 +101,6 @@
 #define DPRINTF(fmt, ...)
 #endif
 
-struct hpet_fw_config hpet_cfg = {.count = UINT8_MAX};
-
 GlobalProperty pc_compat_4_2[] = {};
 const size_t pc_compat_4_2_len = G_N_ELEMENTS(pc_compat_4_2);