I am aware of the ability to have more than one hid device on one usb connection. Is it possible to have two separate usb hid devices to control two different computers? I'm running linux with a windows 10 virtual machine that has a dedicated usb controller. I would like to be able to plug in one usb to one of the VM's usb ports and another to a host machine's usb port. I know I could pass through a device to the VM in software but I would really like to avoid that if possible.
So two USB cables then? You would need two USB sockets on the Arduino device.
I'm thinking you could stack a USB host shield on an Arduino with native USB, such as a Leonardo.
There's a couple of issues with power and ground. If both computers are powering the device then they may cross-feed power from one to the other. It is simple to cut the 5V wire in one of the cables or cut jumpers on the shield. Ground is more difficult. There must be a ground on both side for data to pass but any mismatch between the two machines can cause a lot of current to flow.