Networking VirtualBox and qemu instances on windows
1. Run qemu instance with tapX interface (X is 0 to n)
2. Bridge Virtualbox’s “VirtualBox Host-Only Network” Adaptor and Qemu’s Tap interface.
3. Assign IP address to Network Bridge Interface, this will let you access Qemu and VB intances from windows.
4. Assign IP addresses to Qemu (guest OS) and VirtualBox (guest OS) in the same subnet.
You must be able to PING from both guest OSes and from windows HOST OS as well.
I used this setup to access JUNOS (qemu) from Linux (virtual box) for practicing NETCONF protocol.