Description of problem:
Failed to start domain continually due to virDBusCall() during concurrent jobs

Version-Release number of selected component (if applicable):
dbus-1.6.12-8.el7.x86_64
kernel-3.10.0-201.el7.x86_64
libvirt-1.2.8-9.el7.x86_64
qemu-kvm-rhev-2.1.2-13.el7.x86_64
selinux-policy-3.13.1-9.el7.noarch

How reproducible:
100%

Steps to Reproduce:
<1> Scenario 1, Concurrent migrate 3 guests for 512 rounds through TLS connection --p2p
[root@dhcp-66-83-39 433881]# cat /etc/libvirt/libvirtd.conf | grep "^[^#]"
listen_tls = 1
auth_tls = "none"
max_anonymous_clients = 20000
max_workers = 20000
max_requests = 20000
max_client_requests = 5000
log_level = 1
log_filters="1:qemu_monitor_json"
log_outputs="1:file:/var/log/libvirt/libvirtd.log"
[root@dhcp-66-83-39 433881]# cat /etc/libvirt/qemu.conf | grep "^[^#]"
max_processes = 1000
max_files = 10000

[root@dhcp-66-83-39 433881]# sh mig.sh test 10.66.83.39 10.66.83.41
Tue  9 Dec 11:05:19 CST 2014
Loop 1: Migrating test123 from 10.66.83.39 to 10.66.83.41
COMMAND: virsh -c qemu+tls://root@10.66.83.39/system migrate --live --p2p test123 qemu+tls://root@10.66.83.41/system
Migration: [100 %]
Migration: [ 76 %]
real        0m6.096s
user        0m0.033s
sys        0m0.016s
Migration: [100 %]

real        0m12.832s
user        0m0.036s
sys        0m0.023s
Migration: [100 %]

real        0m15.936s
user        0m0.044s
sys        0m0.019s
Loop 1: Migrating test back from 10.66.83.41 to 10.66.83.39
COMMAND: virsh -c qemu+tls://root@10.66.83.41/system migrate --live --p2p test123 qemu+tls://root@10.66.83.39/system
Migration: [100 %]error: error from service: CreateMachine: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.


real        0m30.471s
user        0m0.058s
sys        0m0.036s
Migration: [100 %]
Migration: [100 %]

...

<2> Scenario 2, Libvirt event handler investigation
lifecycle oeprations for guests concurrently

[root@ibm-x3650m3-07 433879]#sh multi_life.sh &
...

Domain r49 started



error: Failed to start domain r64
error: error from service: CreateMachine: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Domain win7 started

Domain win2012 started

error: Failed to destroy domain r64
error: Requested operation is not valid: domain is not running
error: Failed to start domain win2008r2
error: error from service: CreateMachine: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.


Actual results:
As shown above steps, when set selinux policy to Permissive, we still can reproduce it.

Logs:
2014-12-08 15:14:25.304+0000: 37356: debug : virEventPollCalculateTimeout:370 : Timeout at 1418051665733 due in 429 ms
2014-12-08 15:14:25.304+0000: 37356: debug : virEventPollRunOnce:642 : EVENT_POLL_RUN: nhandles=15 timeout=429
2014-12-08 15:14:25.448+0000: 37358: error : virDBusCall:1429 : error from service: CreateMachine: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.

Expected results:
libvirt should improve this behavior.

Additional info:
Scripts for above scenarios:
<1>
[root@dhcp-66-83-39 433881]# cat mig.sh
#!/bin/bash

# Migrate a guest back and forth between two hosts, printing progress as it goes
GUEST=$1
HOST1=$2
HOST2=$3
OPTIONS="--live --p2p"
TRANSPORT="tls"


date
for i in `seq 1 20`;
do
    echo "Loop ${i}: Migrating ${GUEST}123 from ${HOST1} to ${HOST2}"
    echo "COMMAND: virsh -c qemu+${TRANSPORT}://root@${HOST1}/system migrate ${OPTIONS} ${GUEST}123 qemu+${TRANSPORT}://root@${HOST2}/system"
    time virsh -c qemu+${TRANSPORT}://root@${HOST1}/system migrate ${OPTIONS} ${GUEST}1 qemu+${TRANSPORT}://root@${HOST2}/system --verbose& pid1=$!
   time virsh -c qemu+${TRANSPORT}://root@${HOST1}/system migrate ${OPTIONS} ${GUEST}2 qemu+${TRANSPORT}://root@${HOST2}/system --verbose& pid2=$!
   time virsh -c qemu+${TRANSPORT}://root@${HOST1}/system migrate ${OPTIONS} ${GUEST}3 qemu+${TRANSPORT}://root@${HOST2}/system --verbose& pid3=$!
    wait $pid1
    wait $pid2
    wait $pid3

    echo "Loop ${i}: Migrating ${GUEST} back from ${HOST2} to ${HOST1}"
    echo "COMMAND: virsh -c qemu+${TRANSPORT}://root@${HOST2}/system migrate ${OPTIONS} ${GUEST}123 qemu+${TRANSPORT}://root@${HOST1}/system"
    time virsh -c qemu+${TRANSPORT}://root@${HOST2}/system migrate ${OPTIONS} ${GUEST}1 qemu+${TRANSPORT}://root@${HOST1}/system --verbose& pid1=$!
    time virsh -c qemu+${TRANSPORT}://root@${HOST2}/system migrate ${OPTIONS} ${GUEST}2 qemu+${TRANSPORT}://root@${HOST1}/system --verbose& pid2=$!
    time virsh -c qemu+${TRANSPORT}://root@${HOST2}/system migrate ${OPTIONS} ${GUEST}3 qemu+${TRANSPORT}://root@${HOST1}/system --verbose& pid3=$!
    wait $pid1
    wait $pid2
    wait $pid3


done
date

<2>
[root@ibm-x3650m3-07 433879]# cat template.sh
#!/bin/sh

Save_dir=/test/save-dir
Dump_dir=/test/dump-dir
XML_dir=/test/guest-xml

mkdir -p /test/save-dir
mkdir -p /test/dump-dir
mkdir -p /test/guest-xml

echo "this is the lifecycle oeprations for guest" $1

virsh dumpxml $1 > $XML_dir/$1.xml
for i in {1..10}
do
virsh start $1
virsh destroy $1
done

virsh start $1
for i in {1..50}
do
virsh suspend $1
virsh resume $1
done

for i in {1..50}
do
virsh save $1 $Save_dir/$1.save
virsh restore $Save_dir/$1.save
done

# dump [--live] [--crash] <domain> <file>
for i in {1..50}
do
virsh dump --crash $1 $Dump_dir/$1.dump
virsh start $1
done

sleep 30

virsh destroy $1

for i in {1..50}
do
virsh undefine $1
virsh define $XML_dir/$1.xml
done

[root@ibm-x3650m3-07 433879]# cat multi_life.sh
#! /bin/sh -
Guests=("r49" "r63" "r64" "r71" "r7" "win2008r2" "win2012" "win7" "win8")

for guest in "${Guests[@]}"
do
sh ./template.sh $guest &
done