These patches were never accepted upstream.

 From the discussions - there seemed to be indication that QEMU already 
supported a
reverse-engineered format (before MS released specs for VHD) called VPC

I would look into that...

Todd Deshane wrote:
> Hi,
>
> On Fri, May 23, 2008 at 5:46 AM, Vikram Singh <Vikram.Singh@rsystems.com> wrote:
>   
>> Hi I want to convert an MS virtual machines to Xen VM .programmatically on
>> linux. Is there any tool or help?
>>
>>     
> I assume you mean MS Virtual PC?
>
> I don't know the status of it, but according to this thread there
> should be support for the VHD disk format:
>
> http://lists.xensource.com/archives/html/xen-devel/2007-06/msg00783.html
>
> Cheers,
> Todd
>
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