Embodiments are directed to managing access to input/output devices by virtual machines (VMs). A first VM and a second VM are implemented. An I/O device controller driver has a first driver portion in the first VM and a second driver portion in the second VM. The first driver portion includes a configuration engine to configure the I/O device controller with I/O device-VM mappings, where a first I/O device is mapped exclusively to the first VM, and a second I/O device is mapped to at least the second VM. The second VM includes a general processing engine to call for I/O devices via the second driver portion, and in response to a call by the general processing engine for access to the first I/O device the second driver portion is to send an access request to the first driver portion.