On 12.11.2020 21:45, Michal Privoznik wrote: > When the host is shutting down then we get PrepareForShutdown > signal on DBus to which we react by creating a thread which > runs virStateStop() and thus qemuStateStop(). But if scheduling > the thread is delayed just a but it may happen that we receive > SIGTERM (sent by systemd) to which we respond by quitting our > event loop and cleaning up everything (including drivers). And > only after that the thread gets to run only to find qemu_driver > being NULL. At this point there is nothing left to do anyways, > the event loop is gone so no API call that qemuStateStop() does > in attempt to save running domains can ever succeed. > > But to be fair, if there was a domain running we would have > registered shutdown inhibitor so we would not get killed by > signal. So there is nothing left to do for qemuStateStop() > anyway. > > Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1895359 > > Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> > --- > src/qemu/qemu_driver.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c > index 05f8eb2cb7..9aa0ce4ec8 100644 > --- a/src/qemu/qemu_driver.c > +++ b/src/qemu/qemu_driver.c > @@ -1046,7 +1046,12 @@ qemuStateStop(void) > int state; > virDomainPtr *domains = NULL; > g_autofree unsigned int *flags = NULL; > - g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(qemu_driver); > + g_autoptr(virQEMUDriverConfig) cfg = NULL; > + > + if (!qemu_driver) > + return -1; > + > + cfg = virQEMUDriverGetConfig(qemu_driver); > > if (!(conn = virConnectOpen(cfg->uri))) > goto cleanup; > Hi, Michal. There is a machinery to handle such issues now in libvirt. https://www.redhat.com/archives/libvir-list/2020-November/msg00667.html Nikolay
