migration: pre_save return int

Modify the pre_save method on VMStateDescription to return an int
rather than void so that it potentially can fail.

Changed zillions of devices to make them return 0; the only
case I've made it return non-0 is hw/intc/s390_flic_kvm.c that already
had an error_report/return case.

Note: If you add an error exit in your pre_save you must emit
an error_report to say why.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20170925112917.21340-2-dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/hw/input/ps2.c b/hw/input/ps2.c
index 77906d5..dff3f1e 100644
--- a/hw/input/ps2.c
+++ b/hw/input/ps2.c
@@ -1216,12 +1216,14 @@ static int ps2_kbd_post_load(void* opaque, int version_id)
     return 0;
 }
 
-static void ps2_kbd_pre_save(void *opaque)
+static int ps2_kbd_pre_save(void *opaque)
 {
     PS2KbdState *s = (PS2KbdState *)opaque;
     PS2State *ps2 = &s->common;
 
     ps2_common_post_load(ps2);
+
+    return 0;
 }
 
 static const VMStateDescription vmstate_ps2_keyboard = {
@@ -1254,12 +1256,14 @@ static int ps2_mouse_post_load(void *opaque, int version_id)
     return 0;
 }
 
-static void ps2_mouse_pre_save(void *opaque)
+static int ps2_mouse_pre_save(void *opaque)
 {
     PS2MouseState *s = (PS2MouseState *)opaque;
     PS2State *ps2 = &s->common;
 
     ps2_common_post_load(ps2);
+
+    return 0;
 }
 
 static const VMStateDescription vmstate_ps2_mouse = {