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Bug 597947 - QEMU could not open USB device
Summary: QEMU could not open USB device
Alias: None
Product: Virtualization Tools
Classification: Community
Component: libvirt
Version: unspecified
Hardware: x86_64
OS: Linux
Target Milestone: ---
Assignee: Libvirt Maintainers
QA Contact:
Depends On:
TreeView+ depends on / blocked
Reported: 2010-05-31 04:57 UTC by fkhp101
Modified: 2015-03-16 15:25 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
gentoo linux
Last Closed: 2015-03-16 15:25:09 UTC

Attachments (Terms of Use)

Description fkhp101 2010-05-31 04:57:35 UTC
Description of problem:
vm configure to use usb device but can not use it.

log message in /var/log/libvirt/qemu/vm.log
husb: open device 5.3
/dev/bus/usb/005/003: Operation not permitted
Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
Actual results:

Expected results:

Additional info:

Comment 1 fkhp101 2010-08-20 06:06:07 UTC
this is because cgroup enabled and usb is blacklisted, so libviirtd can not
open it. the usb need to be added to cgroup devices, or do not enable cgroup.

Comment 2 Daniel Berrange 2010-08-20 09:54:42 UTC
Ah, I forgot that USB devices appear as character device nodes. libvirt will need to be taught to set those up with cgroups like it already does for disks, serial ports & parallel ports.

Comment 3 Ján Tomko 2015-03-16 15:25:09 UTC
Fixed upstream by:
commit 5919afe3c664df9bacc47055bf7ebf320530582c
Author:     Diego Elio Pettenò <>
AuthorDate: 2010-11-01 12:03:16 +0100
Commit:     Eric Blake <>
CommitDate: 2010-11-01 10:19:51 -0600

    qemu: add the USB devices to the cgroup whitelist
    Make sure that the QEmu process within the cgroup can access the device
    file for the USB device that has to be connected to the virtual domain.

git describe: v0.8.5-6-g5919afe contains: v0.8.6~192

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