RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.

Description of problem:
It seems that libvirt only support hotplug of memory for guests that exhibit NUMA topology. The only way to hot plug/unplug memory is using the balloon driver which is not a safe mechanism for cloud environments as guests may not be cooperating or even malicious.


Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1. Set MaxMemory element in XML.
2. Boot Instance
3. Boot fails with libvirt error.

Actual results:


Expected results:


Additional info:

For x86, qemu mandates the use of a NUMA node to maintain compatibility with windows guests. As the NUMA node is added by qemu, we have to enforce it so that the XML matches the expected config.

A workaround is to add 1 NUMA node to the domain XML, which will be equivalent to the normal configuration.

For non-x86 guests, use of NUMA is not mandated.