I cannot put Jetson TX2 in recovery mode on VM. What can be the problem?

I need to install JetPack (3.1). I am putting Jetson TX2 on recovery mode on VM. But I can’t see it at the terminal.

This is a known problem of VMs, and a big part of why VMs are not officially supported. The host o/s must pass the recovery mode Jetson to the guest VM at all times. During flash the Jetson will repeatedly disconnect and reconnect, and unless the host o/s passes this through to the guest o/s every time without issue, then flash will fail. There is nothing a Jetson can do about this, and it is up to the end user to find a way to dedicate that USB device to pass through to the VM. Mostly this is the realm of support for the VM and not the flash software.