Hyper-V WMI: KVP Exchange aka Data Exchange (Adding New Items From Parent/Host)

Update 12/5/12

A lot has changed since 2008 and many things have stayed the same…  I wanted to provide an update to some of the most commonly viewed posts and this was one of them.

For updated information on this topic please refer to my latest post Customizing The Key Value Pair (KVP) Integration Component.


Original Post

I have gotten a ton of questions about the KVP Exchange or Data Exchange Integration Component…  So what is it and how do I use it?  The KVP Integration component allows the guest and host to query and provide information to each via pairs of Key’s and Value’s. The KVP integration component provides some basic Key’s and Value’s for you, I talked about the host accessible ones in a previous post Hyper-V WMI Using PowerShell Scripts – Part 3 (KVP’s – Guest OS Version) these include things like the fully qualified name, OS version, Processor Architecture etc…  There are also some guest accessible values that provide some information on the parent (host) such as HostName, PhysicalHostName, PhysicalHostNameFullyQualified, and VirtualMachineName.  These values are located in registry under “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Virtual Machine\Guest\Parameters”.  The other thing you can do via the KVP is write registry key’s from the parent (host) and read guest provided registry key’s from the parent (host).  Today I am going to show how to write key’s from the parent into the guest.

Add-KVP.ps1 Script

The AddKvpItems method returns a WMI Job Object see Hyper-V WMI- Rich Error Messages for Non-Zero ReturnValue (no more 32773, 32768, 32700…) for very helpful method to provide rich error messages.


$Vm=Get-WmiObject-Namespaceroot\virtualization-ComputerName$ComputerName-Query“Select * From Msvm_ComputerSystem Where ElementName=’Vista'”
$Kvp=Get-WmiObject-Namespaceroot\virtualization-ComputerName$ComputerName-Query“Associators of {$Vm} Where AssocClass=Msvm_SystemDevice ResultClass=Msvm_KvpExchangeComponent”

$Msvm_KvpExchangeDateItem= ([WmiClass]$Msvm_KvpExchangeDataItemPath).CreateInstance()





And as you can see I have a new registry entry… (btw 64bit Vista SHWEEET!)








Taylor Brown
Hyper-V Integration Test Lead


Comments (8)

  1. Geoff Nordli says:

    It is strange that I am able to get this to work intermittently.  It seems that it will work once, but then not work for a while, and then start working again.

    Do you have any C#, or VBScript examples that do the same thing?



  2. Anil says:

    Hi Mr. Taylor,

    I have not tried this yet. But, considering that this works, is there a way in which I can do the same data exchange with linux guests?

    I want to exchange data with windows and linux guests launched on a hyper v server. Please help me with this.

    – Anil

  3. Mark M says:

    Taylor, this sounds sort of scary — if the parent can modify any Registry value in the child VM, that seems to contradict Jeff Woolsey’s claims about Hyper-V’s security.

    Are there limits to what keys can be modified? Is there a list of those limits somewhere?

    Many thanks in advance.

    Mark Minasi

  4. Anil,

    Currently there is not a KVP integration component for Linux.  This is something we might consider for future releases.


    The host can only modify the "HKEY_LOCAL_MACHINESOFTWAREMicrosoftVirtual MachineGuest" section in the registry.  And the guest can only provide data to the host via the same registy locaiton.  Additionaly this functionality can be disabled on the host via the Virtual Machine Setting UI.


  5. shache says:

    I have to create many VMs. These virtual machines will be built based on a same VHD. So the OS in these machines have the same computer name. I hope the computer name of these VM machine could be modified. But I don’t know how to do it. Could you give me some iedas? Thanks very much.

  6. Chris Martin says:

    Thanks for this great info, I wrote some C# to allow you to call these powershell functions from C#.


  7. Amit says:

    Hi Taylor,

    Is there any way to modify the computer name using a wmi call ?