If we don't have cgroups available and user tries to update blkio parameters for running VM it will crash. It should have been protected by the virCgroupHasController() check but it was never called if the API was executed without any flags. We call virDomainObjGetDefs() which sets `def` and `persistentDef` based on the flags and these two variables should be used to figure out if we need to update LIVE, CONFIG or both states. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1808293 Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; --- src/qemu/qemu_driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 07e9518a9b..8008da6d16 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -9356,7 +9356,7 @@ qemuDomainSetBlkioParameters(virDomainPtr dom, if (virDomainObjGetDefs(vm, flags, &def, &persistentDef) < 0) goto endjob; - if (flags & VIR_DOMAIN_AFFECT_LIVE) { + if (def) { if (!virCgroupHasController(priv->cgroup, VIR_CGROUP_CONTROLLER_BLKIO)) { virReportError(VIR_ERR_OPERATION_INVALID, "%s", _("blkio cgroup isn't mounted")); -- 2.26.2