QEMU/Devices/USB/Root

The following USB controller devices are provided.

xHCI
xHCI controllers can handle USB 1.0/2.0/3.0.

EHCI
EHCI controllers can only handle USB 2.0 (with a few exceptions not included by QEMU), so a companion controller is needed for USB 1.x.

UHCI
Intel and VIA controllers fall into this section. Other vendors tend to use OHCI.

These controllers support USB 1.0 and are more software-intensive than their counterparts, thus less efficient at virtualization.

OHCI
Controllers under this section support USB 1.1.