Hi All: if install StarlingX in compute-node with cpu type 'Skylake-Server-IBRS' , it cannot use 'passthrough' type with keyword hw:cpu_model in favor to create instance It will prompt "No valid host was found. There are not enough hosts available. computer-0: (VCpuModelFilter) Host VCPU model Skylake-Server-IBRS required Passthrough Code 501" After investigation , Libvirt 4.7.0 supports *IBRS (for example IvyBridge-IBRS, Skylake-Server-IBRS) CPU model , but nova and meta favor does not support *IBRS CPU model yet. I have made patch for nova[0] and glance[1]. Nova[0] will support *-IBRS type vcpu when select passthrough Glance[1] will add metadata to support *-IBRS in hw:cpu_model Please review these PRs. Thanks. BR Austin Sun. [0] https://github.com/starlingx-staging/stx-nova/pull/15 [1] https://github.com/starlingx-staging/stx-glance/pull/4