Chapter 64. Virtualization
mbml perf events fail to boot
If a guest virtual machine is set to report
mbmlperf events, it is unable to boot after the host is upgraded to Red Hat Enterprise Linux 7.5.
To work around this problem, disable this setting by removing lines that contain
event name='mbmt', or
event name='mbml'from the
<perf>section of the domain XML configuration file. (BZ#1532553)