IRP_MN_QUERY_DEVICE_RELATION problem

[Chandrakantt]

I am making virtual bus driver for software USB device. I am facing
following
problem in "TargetDeviceRelation" while handling
IRP_MN_QUERY_DEVICE_RELATION

1) Should i create Device Object here.
2) And is yes then what should i give in fourth parameter that is
"Device Type"
as this can be any type of software USB device.

So how does USB bus driver handle this type os situations.

Thanks in Advance
Chandrakant