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/intc/xics.c b/hw/intc/xics.c
index 80c33be02e..cc9816e7f2 100644
--- a/hw/intc/xics.c
+++ b/hw/intc/xics.c
@@ -241,7 +241,7 @@ static void icp_irq(ICSState *ics, int server, int nr, uint8_t priority)
     }
 }
 
-static void icp_dispatch_pre_save(void *opaque)
+static int icp_dispatch_pre_save(void *opaque)
 {
     ICPState *icp = opaque;
     ICPStateClass *info = ICP_GET_CLASS(icp);
@@ -249,6 +249,8 @@ static void icp_dispatch_pre_save(void *opaque)
     if (info->pre_save) {
         info->pre_save(icp);
     }
+
+    return 0;
 }
 
 static int icp_dispatch_post_load(void *opaque, int version_id)
@@ -533,7 +535,7 @@ static void ics_simple_reset(void *dev)
     }
 }
 
-static void ics_simple_dispatch_pre_save(void *opaque)
+static int ics_simple_dispatch_pre_save(void *opaque)
 {
     ICSState *ics = opaque;
     ICSStateClass *info = ICS_BASE_GET_CLASS(ics);
@@ -541,6 +543,8 @@ static void ics_simple_dispatch_pre_save(void *opaque)
     if (info->pre_save) {
         info->pre_save(ics);
     }
+
+    return 0;
 }
 
 static int ics_simple_dispatch_post_load(void *opaque, int version_id)