From: Philippe Mathieu-Daudé <philmd@redhat.com>

When configured with --without-default-devices, the build fails:

     LINK    x86_64-softmmu/qemu-system-x86_64
  /usr/bin/ld: hw/i386/microvm.o: in function `microvm_devices_init':
  hw/i386/microvm.c:157: undefined reference to `serial_hds_isa_init'
  collect2: error: ld returned 1 exit status
  make[1]: *** [Makefile:206: qemu-system-x86_64] Error 1
  make: *** [Makefile:483: x86_64-softmmu/all] Error 2

While the MicroVM machine only uses the ISA serial port when the
MICROVM_MACHINE_ISA_SERIAL property is set, it has to be linked
with it. Replace the 'imply' Kconfig rule by a 'select'.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191231183216.6781-4-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/i386/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
index 91cf584..cdc8515 100644
--- a/hw/i386/Kconfig
+++ b/hw/i386/Kconfig
@@ -95,7 +95,7 @@ config Q35
 
 config MICROVM
     bool
-    imply SERIAL_ISA
+    select SERIAL_ISA # for serial_hds_isa_init()
     select ISA_BUS
     select APIC
     select IOAPIC
-- 
1.8.3.1