USB3 is backwards compatible with USB1.1.
USB1.1 is translated to USB3 by the hub. It's down to the hub (and its firmware), not the Mac as such.
You don't turn the Virus into anything. The USB1.1 protocol is translated by the hub and everything is piped back to the host as USB3 (or USB2). Priorities are down to the firmware on the hub.
Interestingly, Marc and the Access guys told us some time ago, that the Virus USB chip is actually a USB2.0 device running at USB1.1 speeds. They just didn't have the processor grunt to host the full USB2 stack. ...and it wasn't necessary to achieve the requirements.
i do know a little about this stuff, although USB isn't my area of expertise. In my day job, I'm a principal engineer at one of the biggest consumer electronics companies. I could do some research and go into greater technical detail if you like? There's lots of info on this stuff on the Internet.
...but here are some useful diagrams, showing how hubs work in terms of translation. Bear in mind that hosts such as a Mac or PC have their own hubs on-board.