(This bug is a follow-up item to the: https://bugzilla.redhat.com/show_bug.cgi?id=1547954 -- Deployment RFE: add ability to configure extra CPU flags for named CPU models) This introduced the Nova configuration attribute `[libvirt]/cpu_model_extra_flags`, we have restricted the choices to be only 'PCID' -- to alleviate the immediate guest performance degradation as a result of applying the "Meltdown" CVE fixes. Now remove that restriction to allow adding and removing multiple CPU flags, making way for other use cases. Use cases: - Ability to use 1GB huge pages with Haswell model as one use case for extra flags: cpu_model=Haswell-noTSX-IBRS cpu_model_extra_flags="pdpe1gb" - Nested Virtualization -- an operator can specify the Intel 'vmx' or AMD 'svm' flags in the level-1 Nova guest.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2019:0045