[PATCH] xend: do not polling vcpus info if guest state is not RUNNING or PAUSED

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

When created new guest on NUMA server, xend tried to get the best node by
calculated all vcpus info, the race is if other geust is rebooting, the
guest in the list when entered find_relaxed_node(), but when call
getVCPUInfo() the guest be terminated, then getVCPUInfo() will fail with
below error:

[2013-09-04 20:01:26 6254] ERROR (XendDomainInfo:496) VM start failed
Traceback (most recent call last):
  File "/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line 482, in start
    XendTask.log_progress(31, 60, self._initDomain)
  File "/usr/lib64/python2.4/site-packages/xen/xend/XendTask.py", line 209, in log_progress
    retval = func(*args, **kwds)
  File "/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line 2918, in _initDomain
    node = self._setCPUAffinity()
  File "/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line 2835, in _setCPUAffinity
    best_node = find_relaxed_node(candidate_node_list)[0]
  File "/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line 2803, in find_relaxed_node
    cpuinfo = dom.getVCPUInfo()
  File "/usr/lib64/python2.4/site-packages/xen/xend/XendDomainInfo.py", line 1600, in getVCPUInfo
    raise XendError(str(exn))
XendError: (3, 'No such process')

This patch will let find_relaxed_node() only polling the RUNNING or PAUSED
guest vpus info to avoid the race.

Signed-off-by: Joe Jin <joe.jin@oracle.com>
---
 tools/python/xen/xend/XendDomainInfo.py |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py
index e9d3e7e..66e4b9f 100644
--- a/tools/python/xen/xend/XendDomainInfo.py
+++ b/tools/python/xen/xend/XendDomainInfo.py
@@ -2734,6 +2734,8 @@ class XendDomainInfo:
                 from xen.xend import XendDomain
                 doms = XendDomain.instance().list('all')
                 for dom in filter (lambda d: d.domid != self.domid, doms):
+                    if dom._stateGet() not in (DOM_STATE_RUNNING,DOM_STATE_PAUSED):
+                        continue
                     cpuinfo = dom.getVCPUInfo()
                     for vcpu in sxp.children(cpuinfo, 'vcpu'):
                         if sxp.child_value(vcpu, 'online') == 0: continue
-- 
1.7.1