> Pattern:
>
> FOO's PCIDeviceInfo method exit is virtio_FOO_exit_pci(), which calls
> virtio_FOO_exit() and virtio_exit_pci().
>
> virtio_{net,serial}_exit() call virtio_cleanup().
>
> virtio_blk_exit() doesn't. Why?
>
> virtio-balloon-pci uses virtio_exit_pci() as exit method. No
> virtio_cleanup()?
>
> virtio-9p-pci doesn't have an exit method. Doesn't feel right.9p does not support hot-plug now. We will implement virtio_9p_exit when we are adding support for hot-plug
