I’m launching a VM using qemu-system-x86_64. I know two ways to pass through a USB device.
Say for example, I had a mouse that showed up in lsusb like
Bus 003 Device 011: ID 6ade:9582 Amazing Mouse Maker
I could pass it through using
-device usb-host,vendorid=0x6ade,productid=0x9582
or
-device usb-host,hostbus=3,hostaddr=11
Neither of these I really like. If I grab it by Vendor/Product ID then I will never be able to reclaim that mouse until the VM is turned off.
If I grab it by BUS and Device number, then I will have to tell Qemu to reacquire it if I unplug it.
Is it possible for me to send it by Port (the actual physical slot)? Say it’s plugged in to Bus 3 Port 2. Can I pass it by that?
Answers:
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Method 1
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.
With 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
All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0