Document URL: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/configuring_and_managing_virtualization/assembly_creating-virtual-machines_configuring-and-managing-virtualization Section Number and Name: Chapter 3. Creating virtual machines Describe the issue: Assume the following scenario: Host OS: RHEL9, supports CPU models X Y Z from Vendor A Guest OS: RHEL7, only supports CPU models X and Y from Vendor A If the hardware has model Z (assume a newer model released after hardware enablement for RHEL7 finished), it is possible to configure the VM with a cpu-model of Z, or with host-model or passthrough, all of which will expose CPU features to the Guest OS that its OS may not be able to handle properly. This is not tested, and may produce undesired results. Suggestions for improvement: Document that the Guest OS version must also support the CPU model and features defined in the Guest XML, when creating/editing a VM, not just the Host OS. Certified CPUs by RHEL version can be found at https://catalog.redhat.com/hardware/search?type=Component|CPU%20Collection&p=1
I suggest to add it to the "Creating VMs" chapter, but feel to document in a more suitable location.
Annotation: Chapter 3. Creating virtual machines of the "Configuring and managing virtualization" title. Suggestion to add content to the "Creating VMs" chapter.