[libvirt] [PATCH v4 0/3] usb devices with same vendorID, productID hotplug support

v4 updates: make each patch not break build make usbDeviceSearch flags filtering code simpler https://bugzilla.redhat.com/show_bug.cgi?id=815755 The set of patch tries to fix the issue when multiple usb devices with same idVendor, idProduct are availible on host, the usb device with lowest bus:device will be attached to guest if usb xml file is given like this: <hostdev mode='subsystem' type='usb' managed='yes'> <source> <vendor id='0x15e1'/> <product id='0x2007'/> </source> </hostdev> The reason is that the usb hotplug function searchs usb device in system files to match vendor and product id, the file with lowest number is always found first. After fix, in this case, libvirt will report an error like: # virsh attach-device rhel6u1 /tmp/usb.xml error: Failed to attach device from /tmp/usb.xml error: operation failed: multiple USB devices for 15e1:2007, use <address> to specify one At the same time, the usb part of domain initilization is also updated in patch 2/3 These patches also fix the problem when using the following xml, the usb device could be hotplugged in two domains without raising errors <hostdev mode='subsystem' type='usb' managed='yes'> <source> <address bus='6' device='7'/> </source> </hostdev> # virsh attach-device rhel6u12nd /tmp/usb_by_bus.xml error: Failed to attach device from /tmp/usb_by_bus.xml error: Requested operation is not valid: USB device 006:007 is in use by domain rhel6u1