Actually, the first time that i run virsh atach-device, i get

root@sergelap:~# sudo virsh attach-device maverick2 /tmp/a.xml
error: Failed to attach device from /tmp/a.xml
error: operation failed: adding usb-host,hostbus=002,hostaddr=016,id=hostdev0 device failed: husb: using sys file-system with /dev/bus/usb

Syslog then claims:

Sep 16 21:20:20 sergelap libvirtd: 21:20:20.475: warning : qemudParsePCIDeviceStrs:1422 : Unexpected exit status '1', qemu probably failed
Sep 16 21:20:20 sergelap libvirtd: 21:20:20.479: error : qemuMonitorTextAddDevice:2340 : operation failed: adding usb-host,hostbus=002,hostaddr=016,id=hostdev0 device failed: husb: using sys file-system with /dev/bus/usb#015#012
Sep 16 21:20:20 sergelap kernel: [49160.665916] type=1400 audit(1284690020.467:344): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117



The second time it claims succes:

root@sergelap:~#  virsh attach-device maverick2 /tmp/a.xml
Device attached successfully

but starts filling the logs with the error message:

Sep 16 21:21:35 sergelap libvirtd: 21:21:35.745: warning : qemudParsePCIDeviceStrs:1422 : Unexpected exit status '1', qemu probably failed
Sep 16 21:21:36 sergelap kernel: [49236.685478] type=1400 audit(1284690096.547:345): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117
Sep 16 21:21:38 sergelap kernel: [49238.685623] type=1400 audit(1284690098.547:346): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117
Sep 16 21:21:40 sergelap kernel: [49240.686528] type=1400 audit(1284690100.547:347): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117
Sep 16 21:21:42 sergelap kernel: [49242.685611] type=1400 audit(1284690102.557:348): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117
Sep 16 21:21:44 sergelap kernel: [49244.686534] type=1400 audit(1284690104.557:349): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117
Sep 16 21:21:46 sergelap kernel: [49246.687311] type=1400 audit(1284690106.567:350): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117
Sep 16 21:21:48 sergelap kernel: [49248.688348] type=1400 audit(1284690108.567:351): apparmor="DENIED" operation="open" parent=1 profile="libvirt-27f9f30c-5632-2504-5006-e329fcf24d32" name="/dev/bus/usb/002/016" pid=10138 comm="kvm" requested_mask="rw" denied_mask="rw" fsuid=117 ouid=117