On Tue, 2022-08-09 at 18:33 +0200, Greg Kroah-Hartman wrote: > On Tue, Aug 09, 2022 at 04:31:04PM +0200, Bastien Nocera wrote: > > On Tue, 2022-08-09 at 12:38 +0200, Greg Kroah-Hartman wrote: > > > Now if you really really want to disable a device from under a > > > user, > > > without the file handle present, you can do that today, as root, > > > by > > > doing the 'unbind' hack through userspace and sysfs. It's so > > > common > > > that this seems to be how virtual device managers handle virtual > > > machines, so it should be well tested by now. > > > > The only thing I know that works that way is usbip, and it requires > > unbinding each of the interfaces: > > > > https://sourceforge.net/p/usbip/git-windows/ci/master/tree/trunk/userspace/src/bind-driver.c#l157 > > virtio devices also use the api from what I recall. I can't find any code that would reference /sys/bus/usb/drivers/usbfs/unbind or /sys/bus/usb/drivers/usbfs wrt virtio. Where's the host side code for that? > > That means that, for example, revoking access to the raw USB device > > that OpenRGB used to blink colours across a keyboard would > > disconnect > > the keyboard from the HID device. > > No, you unbind the usbfs driver, not the hid driver. Honestly, I don't understand how this is supposed to work. The USB device is bound to the usb_generic driver, usbfs doesn't have a link to the devices it's supposed to handle.
