When using "virsh attach-device" to attach a device, the virDomainDefCompatibleDevice function will check the compatibility. If the device is a USB device, but the VM don't have any USB controller, the execution of "virsh attach-device" will fails. It considers the USB controller as a USB device on virDomainDeviceIsUSB, so we can't use "virsh attach-device" to attach a USB controller for a VM which don't have any other USB controller. >From ec3257407a9c4aadcd4554dcaad00d40387cf488 Mon Sep 17 00:00:00 2001 From: Liu Ji <jeremy.liu(a)huawei.com&gt; Date: Thu, 5 Sep 2013 09:56:42 +0800 Subject: [PATCH] domain_conf: Delete the USB controller check from the USB Device checklist on virDomainDeviceIsUSB Delete the USB controller check from the USB Device checklist on virDomainDeviceIsUSB, otherwise we can't use "virsh attach-device" to attach a USB controller for a VM which don't have any other USB controller. Signed-off-by: Liu Ji <jeremy.liu(a)huawei.com&gt; --- src/conf/domain_conf.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index e3aec69..ffb3254 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -16899,8 +16899,6 @@ virDomainDeviceIsUSB(virDomainDeviceDefPtr dev) int t = dev->type; if ((t == VIR_DOMAIN_DEVICE_DISK && dev->data.disk->bus == VIR_DOMAIN_DISK_BUS_USB) || - (t == VIR_DOMAIN_DEVICE_CONTROLLER && - dev->data.controller->type == VIR_DOMAIN_CONTROLLER_TYPE_USB) || (t == VIR_DOMAIN_DEVICE_INPUT && dev->data.input->type == VIR_DOMAIN_INPUT_BUS_USB) || (t == VIR_DOMAIN_DEVICE_HOSTDEV &&