Well, in my case I was using USB smart card reader and smart card and it worked. When the USB reader was first connected to VM, Parallels displayed notification that the device was not connected to VM, however device was not visible under VM | System Report | Hardware | USB. Then (with USB device "connected"), I restarted the VM and USB smart card reader was now visible and usable in VM.
So (at least) external HDDs and USB smart card readers (tested with Gemalto IDBridge CT30 and ACS ACR39U-N1) work.
So (at least) external HDDs and USB smart card readers (tested with Gemalto IDBridge CT30 and ACS ACR39U-N1) work.
