migration: extend migration_bitmap

Prevously, if we hotplug a device(e.g. device_add e1000) during
migration is processing in source side, qemu will add a new ram
block but migration_bitmap is not extended.
In this case, migration_bitmap will overflow and lead qemu abort
unexpectedly.

Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/exec.c b/exec.c
index 251dc79e10..b7f7f9818f 100644
--- a/exec.c
+++ b/exec.c
@@ -1414,6 +1414,11 @@ static ram_addr_t ram_block_add(RAMBlock *new_block, Error **errp)
         }
     }
 
+    new_ram_size = MAX(old_ram_size,
+              (new_block->offset + new_block->max_length) >> TARGET_PAGE_BITS);
+    if (new_ram_size > old_ram_size) {
+        migration_bitmap_extend(old_ram_size, new_ram_size);
+    }
     /* Keep the list sorted from biggest to smallest block.  Unlike QTAILQ,
      * QLIST (which has an RCU-friendly variant) does not have insertion at
      * tail, so save the last element in last_block.