id summary reporter owner description type status component version resolution keywords cc guest host 7462 USB device not available in a guest using more than 1 CPU Ludovic "If I configure my guest OS to use more than 1 CPU then I can't use my USB device. I have a iMac model iMac11,1 with a Intel Core i7 (4 CPU with 2 threads each) The USB device is a CCID smart card reader with vID=0x08E6 and pID=0x3437. The device works great if the guest uses only 1 CPU. But I get errors if I configure VirtualBox to use 2 or more CPU for the guest. The errors reported by the kernel are: {{{ [ 56.092448] usb 2-1: new full speed USB device using ohci_hcd and address 2 [ 62.637182] atkbd.c: Spurious NAK on isa0060/serio0. Some program might be trying access hardware directly. [ 71.249524] usb 2-1: device descriptor read/64, error -110 [ 86.512425] usb 2-1: device descriptor read/64, error -110 [ 86.809503] usb 2-1: new full speed USB device using ohci_hcd and address 3 [ 101.976574] usb 2-1: device descriptor read/64, error -110 [ 117.240584] usb 2-1: device descriptor read/64, error -110 [ 117.536353] usb 2-1: new full speed USB device using ohci_hcd and address 4 [ 122.578952] usb 2-1: device descriptor read/8, error -110 [ 127.698748] usb 2-1: device descriptor read/8, error -110 [ 127.996433] usb 2-1: new full speed USB device using ohci_hcd and address 5 [ 133.042903] usb 2-1: device descriptor read/8, error -110 [ 138.161658] usb 2-1: device descriptor read/8, error -110 [ 138.264556] hub 2-0:1.0: unable to enumerate USB device on port 1 }}} and the lsusb command line tools is locked until the kernel gives up enumerating the device. I have the problem with Debian testing/squeeze and also with Ubuntu 10.04. It is quiet easy to reproduce. I also tried with Windows 7 and the device is visible with 1 CPU but not with a 2 CPU guest. So the problem is not limited to a Linux guest or the Linux kernel. Since the problem is not linked to the guest OS it must be in VirtualBox itself." defect closed USB VirtualBox 4.0.8 fixed Linux Mac OS X