On Thu, Jan 07, 2021 at 05:50:10PM +0100, Erik Skultety wrote: > On Thu, Dec 24, 2020 at 08:14:24AM -0600, Jonathon Jongsma wrote: > > This patch series follows the previously-merged series which added support for > > transient mediated devices. This series expands mdev support to include > > persistent device definitions. Again, it relies on mdevctl as the backend. > > > > It follows the common libvirt pattern of APIs by adding the following new APIs > > for node devices: > > - virNodeDeviceDefineXML() - defines a persistent device > > - virNodeDeviceUndefine() - undefines a persistent device > > - virNodeDeviceCreate() - starts a previously-defined device > > > > It also adds virsh commands mapping to these new APIs: nodedev-define, > > nodedev-undefine, and nodedev-start. > > > > Since we rely on mdevctl for the definition of ediated devices, we need a way > > to stay up-to-date with devices that are defined by mdevctl (outside of > > libvirt). The method for staying up-to-date is currently a little bit crude > > due to the fact that mdevctl does not emit any events when new devices are > > added or removed. As a workaround, we create a file monitor for the mdevctl > > config directory and re-query mdevctl when we detect changes within that > > directory. In the future, mdevctl may introduce a more elegant solution. > > > > changes in v3: > > - streamlined tests -- removed some unnecessary duplication > > - split out patch to factor out node device name generation function > > - split nodeDeviceParseMdevctlChildDevice() into a separate function > > - added follow-up patch to remove space-padded alignment in header > > - refactored the mdevctl update handling significantly: > > - no longer a separate persistent thread that gets signaled by a timer > > - now piggybacks onto the existing udev thread and signals the thread in t= > > he > > same way that the udev event does. > > - Daniel suggested spawning a throw-away thread to handle mdevctl updates, > > but that introduces the complexity of possibly serializing multiple > > throw-away threads (e.g. if we get an 'created' event followed immediate= > > ly > > by a 'deleted' event, two threads may be spawned and we'd need to ensure > > they are properly ordered) > > - added virNodeDeviceObjListForEach() and virNodeDeviceObjListRemoveLocked() > > to simplify removing devices that are removed from mdevctl. > > - coding style fixes > > - NOTE: per Erik's request, I experimented with changing the way that mdevctl > > commands were generated and tested (e.g. introducing something like > > virMdevctlGetCommand(def, MDEVCTL_COMMAND_<SUBCOMMAND>, ...)), but it was > > too invasive and awkward and didn't seem worthwhile > > Thanks for giving ^this a try :) > > I think we're converging nicely with the only remaining bit to agree on being > the mdevctl monitoring thread. I think we can target 7.1.0 with this series. The lifecycle events handling in this series is totally broken and needs addressing before we can consider merging. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
