KVM virtualization still does not provide any support for guest 3D acceleration so it comes down to bare metal vs. VirtualBox for these few 3D tests. However, the guest OpenGL acceleration from Oracle's virtualization platform is rather poor. More 3D tests using VirtualBox are available in this Phoronix article. Generally, the Gallium3D-based driver architecture offered by VMware does much better for guest 3D acceleration that is passed onto the host.
Similar to previous Linux virtualization benchmarks published on Phoronix, KVM on the Intel Core i7 Ivy Bridge system tended to be noticeably faster than using Oracle's VM VirtualBox 4.1 software.