[Qemu-devel] [PATCH v6 19/33] dimm: keep the state of the whole backend memory

[Xiao Guangrong]

QEMU keeps the state of memory of dimm device during live migration,
however, it is not enough for nvdimm device as its memory does not
contain its label data, so that we should protect the whole backend
memory instead

Signed-off-by: Xiao Guangrong <guangrong.x...@linux.intel.com>
---
 hw/mem/dimm.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/mem/dimm.c b/hw/mem/dimm.c
index 498d380..44447d1 100644
--- a/hw/mem/dimm.c
+++ b/hw/mem/dimm.c
@@ -134,9 +134,16 @@ void dimm_memory_plug(DeviceState *dev, MemoryHotplugState 
*hpms,
     }
 
     memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr);
-    vmstate_register_ram(mr, dev);
     numa_set_mem_node_id(addr, memory_region_size(mr), dimm->node);
 
+    /*
+     * save the state only for @mr is not enough as it does not contain
+     * the label data of NVDIMM device, so that we keep the state of
+     * whole hostmem instead.
+     */
+    vmstate_register_ram(host_memory_backend_get_memory(dimm->hostmem, errp),
+                         dev);
+
 out:
     error_propagate(errp, local_err);
 }
@@ -145,10 +152,13 @@ void dimm_memory_unplug(DeviceState *dev, 
MemoryHotplugState *hpms,
                            MemoryRegion *mr)
 {
     DIMMDevice *dimm = DIMM(dev);
+    MemoryRegion *backend_mr;
+
+    backend_mr = host_memory_backend_get_memory(dimm->hostmem, &error_abort);
 
     numa_unset_mem_node_id(dimm->addr, memory_region_size(mr), dimm->node);
     memory_region_del_subregion(&hpms->mr, mr);
-    vmstate_unregister_ram(mr, dev);
+    vmstate_unregister_ram(backend_mr, dev);
 }
 
 int qmp_dimm_device_list(Object *obj, void *opaque)
-- 
1.8.3.1