can i run VMware and KVM on a single host

Solution 1:

in short - NO. Both platforms use their own kmod to manage the VT extensions, and the module requires exclusiveness.

Solution 2:

As P Marecki said, YES, you can run them in parallel. Specifically VMware workstation can start VMs in parallel with KVM machines. However, this means that only KVM will be allowed hardware support (VT). In VMware you must explicitly disable this feature and enable "binary translation". An old, but still valid, article for how to do it can be found here. (Our colleagues should be more positive, investigating for their answers than just telling off others).

Furthermore, you can do the same with VBox, which can also co-exist with KVM, if you disable VT and enable binary translation. All these are penalising severely performance, though.

If you want KVM to work this way, well, you cannot. You have to use QEMU only (without the qemu-kvm), with several tricks to make it run without VT.