Hi, same problem on my machine ... Comment #23 does not work for me. In my VM log I found this line:
libusb_set_configuration: -6 [BUSY] I'm running 14.04 (fresh install), QEMU 2.0.0. Any suggestions? -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1392504 Title: libvirt not relabeling devices on USB Passthrough Status in QEMU: New Status in libvirt package in Ubuntu: Triaged Bug description: After upgrading from Ubuntu 14.04 to Ubuntu 14.10 USB passthrough in QEMU (version is now 2.1.0 - Debian2.1+dfsg-4ubuntu6.1) is not working any more. Already tried to remove and attach the USB devices. I use 1 USB2 HDD + 1 USB3 HDD to a virtual linux machine; 1 USB2 HDD to a virual FNAS machine and a USB 2camera to virtual Win7 machine. All these devices are not working any more. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1392504/+subscriptions
