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Diffstat (limited to 'results/classifier/105/instruction/1586611')
| -rw-r--r-- | results/classifier/105/instruction/1586611 | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/results/classifier/105/instruction/1586611 b/results/classifier/105/instruction/1586611 new file mode 100644 index 00000000..75d887bf --- /dev/null +++ b/results/classifier/105/instruction/1586611 @@ -0,0 +1,38 @@ +instruction: 0.853 +graphic: 0.843 +device: 0.778 +KVM: 0.762 +other: 0.760 +semantic: 0.688 +network: 0.679 +vnc: 0.632 +mistranslation: 0.608 +socket: 0.559 +boot: 0.511 +assembly: 0.271 + +usb-hub can not be detached when detach usb device from VM + +I give a host usb device to guest in the way of passthrough,use "virsh attach-device" cmd. In guest os,use "lsusb" cmd I can see two devices have been added,one is usb device and the other is usb-hub（0409:55aa NEC Corp. Hub）. +when I use "virsh detach-device" detach the usb device,in guest os the usb-hub was still exists. +It can create a bad impression when operating the VM,for example,suspend and resume the VM,qemu would report that: + +2016-05-24T12:03:54.434369Z qemu-kvm: Unknown savevm section or instance '0000:00:01.2/2/usb-hub' 0 + +2016-05-24T12:03:54.434742Z qemu-kvm: load of migration failed: Invalid argument + +From qemu's code,it can be sure that the usb-hub is generated by qemu,and the process of detaching usb-hub has already been executed,but failed.With adding print information,error as follows: +libusbx: error [do_close] Device handle closed while transfer was still being processed, but the device is still connected as far as we know +libusbx: warning [do_close] A cancellation for an in-flight transfer hasn't completed but closing the device handle + +I found that when I attached an usb device to the VM, the VM would add an usb-hub automatically if there was no usb-hub. +After adding an usb-hub,the VM assigned a port to the actual usb device. When detaching the usb device,the qemu only detach the port,without detaching the usb-hub.So when doing action like migrating or suspending/resumming,the VM will fail. + +Try detach the usb-hub device by the virsh detach-device usb-hub.xml? + +Of course using virtual usb controller is normal,The situation of the problems is to use the passthrough usb devices + +The usb-hub device should be deleted when the usb device was detached. When do you fix this bug? + +Use a newer libvirt version which manages usb addressing and assigns usb devices to usb ports. This is required to make sure the physical device tree is the same after vmsave/vmload or live migration. + |