[libvirt] [PATCH 00/23] Enable proper use of systemd socket activation with libvirtd

[Daniel P. Berrangé]

On Thu, Jun 27, 2019 at 01:56:45PM +0200, Martin Kletzander wrote:
> On Thu, Jun 27, 2019 at 10:54:29AM +0100, Daniel P. Berrangé wrote:
> > The libvirtd daemon has some support for systemd socket activation
> > from:
> > 
> >  commit 27a7081c2968ca0d7fbd590629b5a5303851f4a3
> >  Author: Martin Kletzander <mkletzan at redhat.com>
> >  Date:   Tue Jul 15 15:28:53 2014 +0200
> > 
> >    daemon: support passing FDs from the calling process
> > 
> >    First FD is the RW unix socket to listen on, second one (if
> >    applicable) is the RO unix socket.
> > 
> > This was originally intended for use by the libvirt client when doing
> > auto-spawning of libvirtd, but we later deleted that client side code
> > in
> > 
> >  commit be78814ae07f092d9c4e71fd82dd1947aba2f029
> >  Author: Michal Privoznik <mprivozn at redhat.com>
> >  Date:   Thu Apr 2 14:41:17 2015 +0200
> > 
> >    virNetSocketNewConnectUNIX: Use flocks when spawning a daemon
> > 
> > We never added systemd socket units before as we need libvirtd to start
> > on boot to perform autostart.
> > 
> > It was recently pointed out by Lennart that these two features are not
> > mutually exclusive though. Libvirtd can be set to start on boot, and
> > also have socket unit files.
> > 
> > The idea is that we start libvirtd on boot, perform autostart, and then
> > libvirtd can exit if nothing is running. The socket unit files are then
> > there to start it again when a mgmt app connects.
> > 
> 
> How do you deal with responding to QEMU events, for example proper support for
> <on_poweroff>restart</on_poweroff> ?

If any QEMU guest is running, libvirtd will keep running. The --timeout
option should only let us exit if we have no client apps and no running
QEMUs, unless I'm mis-remembering.


Regards,
Daniel
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