Created attachment 1376987 [details] nova log with domain xml Description of problem: Nova (OpenStack component) defaults to cpu_mode = host-model on all architectures. And then all VM instances fail: "Failed to start libvirt guest: libvirtError: unsupported configuration: CPU mode 'host-model' for aarch64 kvm domain on aarch64 host is not supported by hypervisor." Popular workaround is to use 'host-passthrough' but that breaks live migration on cloud setups with different ARMv8a cpu cores. Version-Release number of selected component (if applicable): 3.10.0 How reproducible: always Steps to Reproduce: 1. Deploy Nova compute component 2. Run VM instance Actual results: "Failed to start libvirt guest: libvirtError: unsupported configuration: CPU mode 'host-model' for aarch64 kvm domain on aarch64 host is not supported by hypervisor." Expected results: Instance runs. Additional info:
After some reading I tried 'cpu_mode=custom' + 'cpu_model=cortex-a53' but such setup broke Nova. CPU snippet from domain definition was: <cpu mode='custom' match='exact' check='partial'> <model fallback='allow'>cortex-a53</model> <topology sockets='1' cores='1' threads='1'/> </cpu>
Thank you for reporting this issue to the libvirt project. Unfortunately we have been unable to resolve this issue due to insufficient maintainer capacity and it will now be closed. This is not a reflection on the possible validity of the issue, merely the lack of resources to investigate and address it, for which we apologise. If you none the less feel the issue is still important, you may choose to report it again at the new project issue tracker https://gitlab.com/libvirt/libvirt/-/issues The project also welcomes contribution from anyone who believes they can provide a solution.