Check out Synergy2. It’s an amazingly useful little utility that allows you to use one keyboard and mouse to control as many computers and monitors as you like. I’ve got it setup at work to control two machines, one mac and one pc, each of which has 2 screens, and it works beautifully. The setup is a bit of a bear to puzzle out despite the extensive documentation, but once you get it working you’ll never consider a KVM setup again. Just the ability to copy and paste between platforms makes it worth considering over a dedicated KVM.