On Mon, Jun 15, 2026 at 04:23:55PM +0200, Peter Krempa via Devel wrote:
From: Peter Krempa <pkrempa@redhat.com>
For socket activation to work our systemd unit files use the following pattern:
[virtlogd.socket] <----(After)--- [virtlogd.service] [virtqemud.socket] <----(After)--- [virtqemud.service]
Now the qemu daemon also wants to use the services provided by those daemons so we have dependency between the two too:
[virtlogd.socket] <----(After)--- [virtlogd.service] ^ +-------------(After+Requires)-------+ | [virtqemud.socket] <----(After)--- [virtqemud.service]
Now on startup everything is fine, because with socket activation, when 'virtqemud.service' wants to use 'virtlogd' services the socket is already up due to the dependency+ordering and opening a connection will cause 'virtlogd.service' to be socket-activated.
On shutdown though there's no transitive 'After' ordering between 'virtqemud.service' and 'virtlogd.service' and thus nothing explicitly telling systemd that if virtlogd was started. In fact systemd is free to translate it that 'virtlogd' and 'virtqemud' need to be stopped before stopping 'virtlogd.socket'.
To illustrate what happens consider the following scenario:
A host is running a VM under virtqemud. 'virtqemud' is configured to attempt shutdown on the VMs before killing them (daemon-based guest shutdown, but the same reproduces also with libvirt-guests). The host is being rebooted.
(virtqemud attempts to shut down guests, but guest takes more than the configured shutdown inhibition timeout, journald output follows):
06:44:02 fedora systemd-logind[664]: Delay lock is active (UID 0/root, PID 991/virtqemud) but inhibitor timeout is reached. 06:44:02 fedora systemd-logind[664]: System is rebooting. [...] 06:44:02 fedora virtlogd[802]: 802: debug : virSystemdNotify:667 : Notify 'STOPPING=1' 06:44:02 fedora systemd[1]: Stopping virtlogd.service - libvirt logging daemon... 06:44:02 fedora systemd[1]: Stopping virtqemud.service - libvirt QEMU daemon... 06:44:02 fedora virtqemud[991]: 991: debug : virSystemdNotify:667 : Notify 'STOPPING=1' 06:44:02 fedora systemd[1]: virtlogd.service: Deactivated successfully. 06:44:02 fedora systemd[1]: Stopped virtlogd.service - libvirt logging daemon.
(the shutdown times out, virtqemud kills the unresponsive vm)
06:44:27 fedora virtqemud[991]: 1053: debug : qemuProcessStop:8916 : Shutting down vm=0x7f71ac032670 name=virt-vm1 id=1 pid=805, reason=destroyed, asyncJob=none, flags=0x0 06:44:27 fedora virtqemud[991]: 1053: debug : qemuDomainLogAppendMessage:5757 : Append log message (vm='virt-vm1' message='2026-06-15 10:44:27.427+0000: shutting down, reason=destroyed ) stdioLogD=1 06:44:27 fedora virtqemud[991]: 1053: error : virNetSocketReadWire:1767 : Cannot recv data: Connection reset by peer 06:44:27 fedora virtqemud[991]: 1053: debug : qemuProcessKill:8811 : vm=0x7f71ac032670 name=virt-vm1 pid=805 flags=0x5
Now the log shows that we want to add VM log file message in 'qemuDomainLogAppendMessage' but it fails because virtlogd is dead already.
Now the same happens also with 'virtlockd' but with much worse outcome, especially if the configured action is to save the VMs because shutdown of 'virtlockd' when locks are held ends up 'fencing' the VMs by killing them.
The same also happens when libvirt-guests is used to shutdown the guests instead.
This patch adds an explicit 'After=virtlo[ck|g]d.service' to the daemons containing the qemu driver to ensure that the shutdown ordering makes sense. This doesn't break socket activation (e.g. the log/lock daemons are not started unless first invoked).
Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- src/qemu/virtqemud.service.extra.in | 4 ++++ src/remote/libvirtd.service.in | 4 ++++ 2 files changed, 8 insertions(+)
diff --git a/src/qemu/virtqemud.service.extra.in b/src/qemu/virtqemud.service.extra.in index cc16b6a9bb..3cc2edcfd0 100644 --- a/src/qemu/virtqemud.service.extra.in +++ b/src/qemu/virtqemud.service.extra.in @@ -6,6 +6,10 @@ Requires=virtlogd.socket Wants=virtlockd.socket After=virtlogd.socket After=virtlockd.socket
Is there any point in keeping these two lines ? The "Wants" on the socket, and the "After" on the sevice should be enough ?
+# To ensure that our helper daemons are not shut down before the main daemon +# shuts down we need also explicit ordering with the .service unit +After=virtlogd.service +After=virtlock.service Wants=systemd-machined.service After=systemd-machined.service After=remote-fs.target diff --git a/src/remote/libvirtd.service.in b/src/remote/libvirtd.service.in index b0a062e885..f26494d646 100644 --- a/src/remote/libvirtd.service.in +++ b/src/remote/libvirtd.service.in @@ -15,6 +15,10 @@ Requires=virtlogd.socket Wants=virtlockd.socket After=virtlogd.socket After=virtlockd.socket +# To ensure that our helper daemons are not shut down before the main daemon +# shuts down we need also explicit ordering with the .service unit +After=virtlogd.service +After=virtlock.service Wants=systemd-machined.service After=network.target After=dbus.service -- 2.54.0
With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|