The v9 Xen PV drivers works the same way as QWT PV drivers for me in Windows 10.
Enable testsigning in WIndows by running this command in admin console:
bcdedit /set testsigning on
Restart qube.
Install xenbus and xenvbd drivers.
Restart qube.
In some Linux disposable qube run these commands to create test block device:
dd if=/dev/zero of=tst bs=1M count=256
sudo losetup -f tst
Attach this block device to Windows qube.
Open Disk Management and initialize/format the disk.
Create some test file on the disk.
Detach the block device.
Restart the Windows qube.
Attach the block device to Windows qube and check if the file created there exist.