For some reason this is not documented on the Qemu 2.12.50 User Doc and I had to learn what I learned from this guy
They mention:
-device usb-host,hostbus=bus,hostaddr=addr
Pass through the host device identified by bus and addr
-device usb-host,vendorid=vendor,productid=product
Pass through the host device identified by vendor and product ID
But they don't mention that you can also do:
-device usb-host,hostbus=bus,hostport=port
For example...
Running lsusb -t, I get:
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/14p, 480M
|__ Port 10: Dev 8, If 0, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 11: Dev 6, If 0, Class=Human Interface Device, Driver=usbhid, 12M
I could decide to pass these with:
-device usb-host,hostbus=3,hostport=10 \
-device usb-host,hostbus=3,hostport=11 \
And those correspond to the physical slots.
However the bus and port will differ for a USB 3.0 slot depending on if a USB 2.0 device or USB 3.0 device is plugged into it, but the port for each device will remain consistent.
Such variance does not exist for USB 2.0 slots.
Update: USB Hubs
UseWith USB hubs, use dots to separate the ports. So if you had ...
/: Bus 03
|__ Port 2: some stuff
|__ Port 1: some stuff
You would use -device usb-host,hostbus=3,hostport=2.1
