s390x: vmstatify config migration for virtio-ccw

Let's vmstatify virtio_ccw_save_config and virtio_ccw_load_config for
flexibility (extending using subsections) and for fun.

To achieve this we need to hack the config_vector, which is VirtIODevice
(that is common virtio) state, in the middle of the VirtioCcwDevice state
representation.  This is somewhat ugly, but we have no choice because the
stream format needs to be preserved.

Almost no changes in behavior. Exception is everything that comes with
vmstate like extra bookkeeping about what's in the stream, and maybe some
extra checks and better error reporting.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-Id: <20170703213414.94298-1-pasic@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/include/hw/s390x/css.h b/include/hw/s390x/css.h
index 596a2f2..eb0e26f 100644
--- a/include/hw/s390x/css.h
+++ b/include/hw/s390x/css.h
@@ -88,6 +88,7 @@
     bool ccw_fmt_1;
     bool thinint_active;
     uint8_t ccw_no_data_cnt;
+    uint16_t migrated_schid; /* used for missmatch detection */
     /* transport-provided data: */
     int (*ccw_cb) (SubchDev *, CCW1);
     void (*disable_cb)(SubchDev *);
@@ -96,6 +97,8 @@
     void *driver_data;
 };
 
+extern const VMStateDescription vmstate_subch_dev;
+
 /*
  * Identify a device within the channel subsystem.
  * Note that this can be used to identify either the subchannel or
@@ -118,18 +121,21 @@
     hwaddr addr;
     uint64_t map;
     unsigned long refcnt;
-    int len;
+    int32_t len;
     QTAILQ_ENTRY(IndAddr) sibling;
 } IndAddr;
 
+extern const VMStateDescription vmstate_ind_addr;
+
+#define VMSTATE_PTR_TO_IND_ADDR(_f, _s)                                   \
+    VMSTATE_STRUCT(_f, _s, 1, vmstate_ind_addr, IndAddr*)
+
 IndAddr *get_indicator(hwaddr ind_addr, int len);
 void release_indicator(AdapterInfo *adapter, IndAddr *indicator);
 int map_indicator(AdapterInfo *adapter, IndAddr *indicator);
 
 typedef SubchDev *(*css_subch_cb_func)(uint8_t m, uint8_t cssid, uint8_t ssid,
                                        uint16_t schid);
-void subch_device_save(SubchDev *s, QEMUFile *f);
-int subch_device_load(SubchDev *s, QEMUFile *f);
 int css_create_css_image(uint8_t cssid, bool default_image);
 bool css_devno_used(uint8_t cssid, uint8_t ssid, uint16_t devno);
 void css_subch_assign(uint8_t cssid, uint8_t ssid, uint16_t schid,