Hyper-V is not something that runs within Windows. It's a bare metal Hypervisor. The OS that used to be installed on the machine is actually now a VM. It's a special VM in that it has direct access to the hardware, doesn't show up in Hyper-V's management console, and other such; but it's still now a VM. So it doesn't get to see what the other machines are doing any more than they can see it.
Since Hyper-V still uses the base OS for servicing disk and network IO, you can pull those numbers from PerfMon. The Memory and Processor numbers obtains from PerfMon are skewed however and should be taken with a grain of salt.
