On 6/25/22 13:00, Simon Fairweather wrote: I don't think so. I haven't found any bug/gitlab issue requesting it. Sure. Firstly, you'll need to expose this as an <hostdev/> attribute: <hostdev mode='subsystem' type='usb' managed='no' reset='yes'> <source> <address bus='14' device='6'/> </source> </hostdev> Or perhaps as <source/> attribute? <hostdev mode='subsystem' type='usb' managed='no'> <source reset='yes'> <address bus='14' device='6'/> </source> </hostdev> For that you'll need to tweak virDomainHostdevSubsysUSBDefParseXML(). Then, you will need to change qemuBuildUSBHostdevDevProps() to put 'guest_reset' attribute into the props object according to the XML config. This function is called in both cmd line generation and hotplug operations, so there's not much else you need to care for. Now, for the XML part, whenever adding something to XML: 1) the RNG schema must be updated too (src/conf/schemas/domaincommon.rng), 2) a qemuxml2xmltest case must be added (or an existing one extended), 3) cmd line generation must be in a separate commit (because of easier cherry pick). I can only recommend reading: https://libvirt.org/hacking.html Oh, and BTW for libvirt itself we still use mailing list workflow instead of merge requests. Please let me know if you need any help or want me to implement the feature for you. Michal