Libvrit decides which 'accel' value should be passed to qemu command line by reading 'domain type' from xml (if kvm => accel=kvm, if qemu => accel=tcg).
Qemu parses command line and if it contains 'enable-kvm' it add/set accel key value to kvm.
In Ubuntu 'kvm' is a wrapper which append '-enable-kvm' key to qemu command line. In RH is not.
My proposal is change virt_type to kvm in nova.conf
Long time debugging short:
Libvrit decides which 'accel' value should be passed to qemu command line by reading 'domain type' from xml (if kvm => accel=kvm, if qemu => accel=tcg).
Qemu parses command line and if it contains 'enable-kvm' it add/set accel key value to kvm.
In Ubuntu 'kvm' is a wrapper which append '-enable-kvm' key to qemu command line. In RH is not.
My proposal is change virt_type to kvm in nova.conf