While creating a VM instance in openstack (created using devstack), , I have got an issue “this system does not support SSSE3”. The cpu_mode in both /etc/nova/nova.conf and nova-cpu.conf was "none" so I tried changing it to use "host-model" or "host-passthrough". It didn't work on both the cases. I still get the same SSSE3 not supported error. I did grep in "/proc/cpuinfo", and found the ssse3 entry.

Then I tried changing LIBVIRT_CPU_MODE to host-passthrough of "devstack/lib/nova" file and ran unstack.sh and stack.sh. The issue still persists. Please suggest how to resolve this issue?