I have my main/gaming rig that I use for everything unrelated to my career, and I run a Hyper V VM on/with it that I strictly use for just my daily job. (Work from home sysadmin for an MSP)
The company I work for provided me with hardware that I can connect at home and use, but it's much more convenient for me to get everything done utilizing all of my monitors and gaming hardware and not having to have two physical computers set up. The company doesn't care and I keep the work VM pretty isolated from everything else (well, as much as you can with a Hyper V VM and still get all of the functionality I crave.)
There's really no need for a KVM switch, I think having two physical computers to deal with in my case would just complicate things. Running the VM for my work life during work hours and then shutting it down once I'm off the clock is super simple already.
As far as GPU partitioning, all of the clients I work with are spending their day working with things like Excel and Outlook, so nothing graphically demanding.