xend: Don't allow dom0 memory to be ballooned below dom0-min-mem

configuration parameter.

Signed-off-by: Masaki Kanno <kanno.masaki@jp.fujitsu.com>

tools/python/xen/xend/XendDomainInfo.py

@@ -986,6 +986,13 @@ class XendDomainInfo:
                   self.info['name_label'], str(self.domid), target)
         
         MiB = 1024 * 1024
+
+        if self.domid == 0:
+            dom0_min_mem = xoptions.get_dom0_min_mem()
+            memory_cur = self.get_memory_dynamic_max() / MiB
+            if target < memory_cur and dom0_min_mem > target:
+                raise XendError("memory_dynamic_max too small")
+
         self._safe_set_memory('memory_dynamic_min', target * MiB)
         self._safe_set_memory('memory_dynamic_max', target * MiB)