Hi, Thank you for your response, it solved the issue.
virsh domcapabilities
virsh -c qemu:///system?authfile=/etc/ovirt-hosted-engine/virsh_auth.conf domcapabilities error: failed to get emulator capabilities error: internal error: unknown feature amd-sev-es This appeared to be the bug, https://bugzilla.redhat.com/show_bug.cgi?id=1961558 , which as per https://serverfault.com/questions/1065246/virsh-reporting-unknown-feature-am... I ran `yum downgrade edk2-ovmf`. After which domcapabilities reported data correctly. I re-ran the engine installer and that completed successfully. For those playing at home, an additional symptom I noticed was that in 'Edit Cluster' for the default cluster, I could not change CPU Type from 'Auto Detect' - it was an empty drop-down. CPU Architecture was also locked as undefined. Thanks for your help!