migration/vfio: compile only once

Acked-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250730220435.1139101-3-pierrick.bouvier@linaro.org>
[PMD: Cover vfio-stub.c in MAINTAINERS]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

MAINTAINERS

@@ -2268,6 +2268,7 @@ F: util/vfio-helpers.c
 F: include/hw/vfio/
 F: docs/devel/migration/vfio.rst
 F: qapi/vfio.json
+F: migration/vfio-stub.c
 F: tests/functional/aarch64/test_device_passthrough.py
 
 vfio-igd

migration/meson.build

@@ -49,6 +49,6 @@ system_ss.add(when: zstd, if_true: files('multifd-zstd.c'))
 system_ss.add(when: qpl, if_true: files('multifd-qpl.c'))
 system_ss.add(when: uadk, if_true: files('multifd-uadk.c'))
 system_ss.add(when: qatzip, if_true: files('multifd-qatzip.c'))
-
-specific_ss.add(when: 'CONFIG_SYSTEM_ONLY',
-                if_true: files('vfio.c'))
+system_ss.add(when: 'CONFIG_VFIO',
+              if_true: files('vfio.c'),
+              if_false: files('vfio-stub.c'))

migration/vfio-stub.c

@@ -0,0 +1,16 @@
+/*
+ * QEMU live migration - stubs for VFIO
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "migration.h"
+
+void migration_populate_vfio_info(MigrationInfo *info)
+{
+}
+
+void migration_reset_vfio_bytes_transferred(void)
+{
+}

migration/vfio.c

@@ -8,13 +8,8 @@
 #include "qemu/osdep.h"
 #include "qapi/qapi-types-migration.h"
 #include "migration.h"
-#include CONFIG_DEVICES
-
-#ifdef CONFIG_VFIO
 #include "hw/vfio/vfio-migration.h"
-#endif
 
-#ifdef CONFIG_VFIO
 void migration_populate_vfio_info(MigrationInfo *info)
 {
     if (vfio_migration_active()) {
@@ -27,12 +22,3 @@ void migration_reset_vfio_bytes_transferred(void)
 {
     vfio_migration_reset_bytes_transferred();
 }
-#else
-void migration_populate_vfio_info(MigrationInfo *info)
-{
-}
-
-void migration_reset_vfio_bytes_transferred(void)
-{
-}
-#endif