[PATCH] xend: disallow multiple destroy() call

[Joe Jin <joe.jin@oracle.com>]

Current Xend allowing multiple call destroy() for same domain, this lead
multiple hard resets(FLR) for pci pass-through, and some controller might
failed.

In our test, we pass through 2 LSI HAB controllers to the PVHVM guest, after
guest brought up, call xm-destroy twice, the adapters's BIOS will hung, and
we had to reboot the server to recovery it.

Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
---
 tools/python/xen/xend/XendDomainInfo.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index e9d3e7e..658c3b6 100644
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -367,6 +367,8 @@ class XendDomainInfo:
     @type refresh_shutdown_lock: threading.Condition
     @ivar _deviceControllers: device controller cache for this domain
     @type _deviceControllers: dict 'string' to DevControllers
+    @ivar destroying: Is this domain destroying
+    @type destroying: bool
     """
     
     def __init__(self, info, domid = None, dompath = None, augment = False,
@@ -455,6 +457,8 @@ class XendDomainInfo:
         self._checkName(self.info['name_label'])
 
         self.metrics = XendVMMetrics(uuid.createString(), self)
+
+        self.destroying = False
             
 
     #
@@ -3073,6 +3077,12 @@ class XendDomainInfo:
 
         if self.domid is None:
             return
+
+        if self.destroying == False:
+            self.destroying = True
+        else:
+            raise VmError("Domain (domid=%s) is destroying, please wait!", str(self.domid))
+
         from xen.xend import XendDomain
         log.debug("XendDomainInfo.destroy: domid=%s", str(self.domid))
 
@@ -3088,6 +3098,7 @@ class XendDomainInfo:
                     self.info[state] = 0
                 self._stateSet(DOM_STATE_HALTED)
             except:
+                self.destroying = False
                 log.exception("XendDomainInfo.destroy: domain destruction failed.")
 
             XendDomain.instance().remove_domain(self)
-- 
1.8.1