diff --git a/hw/intc/s390_flic.c b/hw/intc/s390_flic.c
index efcb1dd..ff6e4ec 100644
--- a/hw/intc/s390_flic.c
+++ b/hw/intc/s390_flic.c
@@ -200,6 +200,22 @@ static void qemu_s390_flic_register_types(void)
 
 type_init(qemu_s390_flic_register_types)
 
+static bool adapter_info_so_needed(void *opaque)
+{
+    return css_migration_enabled();
+}
+
+const VMStateDescription vmstate_adapter_info_so = {
+    .name = "s390_adapter_info/summary_offset",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = adapter_info_so_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(summary_offset, AdapterInfo),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_adapter_info = {
     .name = "s390_adapter_info",
     .version_id = 1,
@@ -213,6 +229,10 @@ const VMStateDescription vmstate_adapter_info = {
          */
         VMSTATE_END_OF_LIST()
     },
+    .subsections = (const VMStateDescription * []) {
+        &vmstate_adapter_info_so,
+        NULL
+    }
 };
 
 const VMStateDescription vmstate_adapter_routes = {
diff --git a/hw/s390x/css.c b/hw/s390x/css.c
index 1aed89f..e9a0613 100644
--- a/hw/s390x/css.c
+++ b/hw/s390x/css.c
@@ -29,12 +29,45 @@ typedef struct CrwContainer {
     QTAILQ_ENTRY(CrwContainer) sibling;
 } CrwContainer;
 
+static const VMStateDescription vmstate_crw = {
+    .name = "s390_crw",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT16(flags, CRW),
+        VMSTATE_UINT16(rsid, CRW),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static const VMStateDescription vmstate_crw_container = {
+    .name = "s390_crw_container",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_STRUCT(crw, CrwContainer, 0, vmstate_crw, CRW),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 typedef struct ChpInfo {
     uint8_t in_use;
     uint8_t type;
     uint8_t is_virtual;
 } ChpInfo;
 
+static const VMStateDescription vmstate_chp_info = {
+    .name = "s390_chp_info",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8(in_use, ChpInfo),
+        VMSTATE_UINT8(type, ChpInfo),
+        VMSTATE_UINT8(is_virtual, ChpInfo),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 typedef struct SubchSet {
     SubchDev *sch[MAX_SCHID + 1];
     unsigned long schids_used[BITS_TO_LONGS(MAX_SCHID + 1)];
@@ -221,6 +254,19 @@ typedef struct CssImage {
     ChpInfo chpids[MAX_CHPID + 1];
 } CssImage;
 
+static const VMStateDescription vmstate_css_img = {
+    .name = "s390_css_img",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        /* Subchannel sets have no relevant state. */
+        VMSTATE_STRUCT_ARRAY(chpids, CssImage, MAX_CHPID + 1, 0,
+                             vmstate_chp_info, ChpInfo),
+        VMSTATE_END_OF_LIST()
+    }
+
+};
+
 typedef struct IoAdapter {
     uint32_t id;
     uint8_t type;
@@ -239,10 +285,34 @@ typedef struct ChannelSubSys {
     uint64_t chnmon_area;
     CssImage *css[MAX_CSSID + 1];
     uint8_t default_cssid;
+    /* don't migrate, see css_register_io_adapters */
     IoAdapter *io_adapters[CSS_IO_ADAPTER_TYPE_NUMS][MAX_ISC + 1];
+    /* don't migrate, see get_indicator and IndAddrPtrTmp */
     QTAILQ_HEAD(, IndAddr) indicator_addresses;
 } ChannelSubSys;
 
+static const VMStateDescription vmstate_css = {
+    .name = "s390_css",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_QTAILQ_V(pending_crws, ChannelSubSys, 1, vmstate_crw_container,
+                         CrwContainer, sibling),
+        VMSTATE_BOOL(sei_pending, ChannelSubSys),
+        VMSTATE_BOOL(do_crw_mchk, ChannelSubSys),
+        VMSTATE_BOOL(crws_lost, ChannelSubSys),
+        /* These were kind of migrated by virtio */
+        VMSTATE_UINT8(max_cssid, ChannelSubSys),
+        VMSTATE_UINT8(max_ssid, ChannelSubSys),
+        VMSTATE_BOOL(chnmon_active, ChannelSubSys),
+        VMSTATE_UINT64(chnmon_area, ChannelSubSys),
+        VMSTATE_ARRAY_OF_POINTER_TO_STRUCT(css, ChannelSubSys, MAX_CSSID + 1,
+                0, vmstate_css_img, CssImage),
+        VMSTATE_UINT8(default_cssid, ChannelSubSys),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static ChannelSubSys channel_subsys = {
     .pending_crws = QTAILQ_HEAD_INITIALIZER(channel_subsys.pending_crws),
     .do_crw_mchk = true,
@@ -282,6 +352,10 @@ static int subch_dev_post_load(void *opaque, int version_id)
         css_subch_assign(s->cssid, s->ssid, s->schid, s->devno, s);
     }
 
+    if (css_migration_enabled()) {
+        /* No compat voodoo to do ;) */
+        return 0;
+    }
     /*
      * Hack alert. If we don't migrate the channel subsystem status
      * we still need to find out if the guest enabled mss/mcss-e.
