Re: [Qemu-devel] Byte ordering of VM Generation ID in Windows VMs

[Richard W.M. Jones]

On Mon, Jul 09, 2018 at 08:36:47AM +0100, Richard W.M. Jones wrote:
> On Thu, Jul 05, 2018 at 03:11:32PM +0100, Richard W.M. Jones wrote:
> > VMware represents these internally as two signed 64 bit integers, eg:
> > 
> >   vm.genid = "-570734802784577186"
> >   vm.genidx = "-5042519231342505152"
> > 
> > I am still trying to get verification, but I believe the first is the
> > low 64 bit word and the second is the high 64 bit word.
> 
> I have now been able to verify how this works using a real VMware
> hypervisor (thanks to help from Ming Xie).  For the record, here is
> how it maps, since I could not find any documentation about this.
> 
> VMX file contains:
> 
>   vm.genid = "7344585841658099715"
>   vm.genidX = "-8483171368186442967"

As a follow-on, here is some code which can convert VMware's VMX
numbers into a qemu-style UUID.  Note for both of these I mean the
textual representation, not the in-memory representation.

  
https://github.com/libguestfs/libguestfs/blob/b11b870166b7ae27f728dbb58b6498788bf97329/v2v/input_vmx.ml#L430-L449

Rich.

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