Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux

Chapter 64. Virtualization

Guests reporting cmt, mbmt, or mbml perf events fail to boot

If a guest virtual machine is set to report cmt, mbmt, or mbml perf 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='cmt', event name='mbmt', or event name='mbml' from the <perf> section of the domain XML configuration file. (BZ#1532553)