Re: [libvirt] ivshmem server

----- Original Message ----- > On Tue, Nov 20, 2012 at 01:16:56PM -0500, Andrew Jones wrote: > > > > This mail is meant to get a discussion started. Please keep me on > > cc > > for the discussion, as I'm not subscribed to libvir-list. > > > > ivshmem is an implementation of an inter-VM communication > > channel. > > Support for this has been in qemu since v0.14.0 and libvirt > > patches > > have been recently posted[1]. What's still missing is the ivshmem > > server. The ivshmem server is needed when one would like to use > > interrupts with ivshmem. The server manages a set of eventfds > > to send/recv those interrupts. There is currently only one > > implementation of this server that I'm aware of, which is > > available > > from this git repo [2] in the ivshmem-server directory. My > > suggestion > > for libvirt is that this code be integrated into libvirt, rather > > than managed by libvirt, for the following reasons > > > > 1. libvirt should keep track of the socket path in order to build > > ivshmem's command line anyway. > > 2. the current ivshmem server code is ~300 lines, so it shouldn't > > be > > a large integration effort. > > 3. keeping ivhsmem server separate increases the package > > management > > that distributions need to do. afaik, it isn't currently > > packaged > > for any distribution. > > > > One concern I have with the git repo [2] is that I don't see any > > license for ivshmem-server. I've cc'ed Cam for his input. > > I guess my main question would be how much more, if any, is the > ivshmem-server expected to grow over time ? I wouldn't want to > get into a fork-situation if people are planning to do much more > dev work on the current ivshmem-server code. Here's the entire git log for ivshmem-server Date: Thu Sep 6 11:36:33 2012 -0600 Error clean-up Fixed a warning and cleaned up two error message Date: Tue Nov 16 11:11:16 2010 -0700 just a few fixups Date: Tue Jun 15 14:43:01 2010 -0600 Adding the ivshmem server here - Cam So there was an initial drop, then nothing for two years, and then some recent cleanups. I believe that it serves a simple enough purpose that there shouldn't be any more growth. > > NB, if the code is integrated into libvirt, I think it would > still have to run in a separate daemon. The reason is that we > want to ensure that guests remain fully functional, even when > libvirtd is stopped (whether for RPM upgrade, or due to crash) > > I've no particular strong opinion either way on your proposal. > On the surface it seems reasonable to me. > > Daniel > -- > |: http://berrange.com -o- > | http://www.flickr.com/photos/dberrange/ :| > |: http://libvirt.org -o- > | http://virt-manager.org :| > |: http://autobuild.org -o- > | http://search.cpan.org/~danberr/ :| > |: http://entangle-photo.org -o- > | http://live.gnome.org/gtk-vnc :| >