Linux VM KVP IP can't be shown on Hyper-V Manager after querying its KVP/IP information on Hyper-V host several times

Question

Hello
[Sorry for asking the same question in the wrong place/forum of "Hyper-V"]
I am using a CentOS 6.5 VM (Linux kernel 2.6.32-431) and (generation 2) CentOS 7 VM (Linux
kernel 3.10.0-123) with Hyper-V KVP daemon installed,
and I periodically query its IP (via using WMI or Powershell to query its KVP information) to manage it.
However, after querying its IP (KVP) for several times, its IP can’t
be queried or shown on Hyper-V Manager anymore (Windows VM is ok without this problem).
And here is the vmIntegrationService status of my CentOS 7 VM for the references.
PS C:\Users\Administrator> (Get-VM -name G2_CentOS7).vmIntegrationService
VMName     Name                    Enabled PrimaryStatusDescription SecondaryStatusDescription
G2_CentOS7 Time Synchronization    True    OK
G2_CentOS7 Heartbeat               True    OK
G2_CentOS7 Key-Value Pair Exchange True    OK                       The protocol version of the component installed ...
G2_CentOS7 Shutdown                True    OK
G2_CentOS7 VSS                     True    No Contact
G2_CentOS7 Guest Service Interface False   OK
I attached a simple KVP query Powershell script as
the follows, and this problem can be reproduced in couple minutes if you run two instances with this script at the same time.
$VMName = $args[0]
write-host "$VMName"
filter Import-CimXml
$CimXml = [Xml]$_
$CimObj = New-Object -TypeName System.Object
foreach ($CimProperty in $CimXml.SelectNodes("/INSTANCE/PROPERTY"))
if ($CimProperty.Name -eq "Name" -or $CimProperty.Name -eq "Data")
$CimObj | Add-Member -MemberType NoteProperty -Name $CimProperty.NAME -Value $CimProperty.VALUE
$CimObj
$CimObj = $null
for ($i=1 ; $i -le 10000 ; $i++) {
$a = Get-Date
write-host "$i - Time: " $a.ToLocalTime()
$vm = Get-WmiObject -Namespace root\virtualization\v2 -Query "Select * From Msvm_ComputerSystem Where ElementName='$VMName'"
$vm.ElementName
$vmkvp = Get-WmiObject -Namespace root\virtualization\v2 -Query "Associators of {$vm} Where AssocClass=Msvm_SystemDevice ResultClass=Msvm_KvpExchangeComponent"
$vmkvp.GuestIntrinsicExchangeItems | Import-CimXml
Actually, if your CentOS VM (has LIS) installed with KVP daemon running well,
my test script will show more than 4 keys (include NetworkAddressIPv4 or NetworkAddressIPv6 keys).
However, while the KVP daemon becomes problematic, it will only show a few keys
(ex. 4~6 keys) and at this moment, Hyper-V Manager also can't show IP address of it anymore and you may need to reboot the CentOS VM to recover it.
For example (KVP in 252 time is good, but KVP in 253 and 254 times become problematic)
252 - Time:  8/26/2014 7:19:42 PM
G2_CentOS7
localhost                                                   FullyQualifiedDomainName
3.1                                                         IntegrationServicesVersion
10.1.145.190;192.168.122.1                                  NetworkAddressIPv4
fe80::215:5dff:fe91:b902                                    NetworkAddressIPv6
3.10.0-123.el7.x86_64                                       OSBuildNumber
0                                                           OSDistributionData
0                                                           OSDistributionName
199168                                                      OSKernelVersion
7                                                           OSMajorVersion
                                                            OSMinorVersion
CentOS Linux                                                OSName
129                                                         OSPlatformId
3.10.0                                                      OSVersion
x86_64                                                      ProcessorArchitecture
253 - Time:  8/26/2014 7:19:42 PM
G2_CentOS7
localhost                                                   FullyQualifiedDomainName
3.1                                                         IntegrationServicesVersion
10.1.145.190;192.168.122.1                                  NetworkAddressIPv4
0                                                           OSDistributionData
0                                                           OSDistributionName
199168                                                      OSKernelVersion
129                                                         OSPlatformId
254 - Time:  8/26/2014 7:19:44 PM
G2_CentOS7
0                                                           OSDistributionData
0                                                           OSDistributionName
199168                                                      OSKernelVersion
129                                                         OSPlatformId
I
found the following patches and gave them a try, but the
problem still remains after applying these patches and the (generation 2) Ubuntu 14.04 with Linux kernel 3.13 also has this problem.
 - Patch "Drivers:
hv: util: Fix a bug in the KVP code" has been added to the 3.14-stable tree
 - Drivers: hv: vmbus: Fix a bug in the channel callback dispatch code
But (generation 1) Ubuntu 14.04 VM with Linux kernel 3.17 doesn't encounter this problem after querying its KVP/IP information on Hyper-V host several times.
Does anyone know what changes between Linux kernel 3.13 and 3.17 fix this issue?
Thanks,
Paul

Answer 1

Hi Dexuan and Mike,
Thanks for your help!
I did the patch with rpmbuild on CentOS 6.5 (with kernel 2.6.32-431).
However, the second patch cannot patch on CentOS6.5 since there is no target_cpu in such version.
So we are patching that with the following similar patch but this issue still occurs. (also replace ko in initrd)
https://lists.ubuntu.com/archives/kernel-team/2014-August/047725.html
Can you tell me if any patch I could miss or any suggestion?
Thanks for your time.