OK, i was reading a document from VMware (understanding full virtualization, paravirtualization, HAV). There it was written that in para virtualization all the priviliged instructions are handled by the hypervisor and the guest OS runs in Ring 0. I didnt understand why the guest OS should be in Ring 0 when all the sensitive instructions are traped into hypervisor. This is same as binary translation where guest OS resides in Ring 3 and VMM resides in Ring 0, then all the sensitive instructions are trapped into VMM. Also, i didnt understand where the VMM resides in paravirtualization when the guest OS runs in Ring 0. Also, in case of Xen the guest OS resides in Ring 1 and VMM in Ring 0, this makes some sense to me (or am i missing something ?) -- Mourya Chintalapati MS, IT (Pervasive Computing) Klagenfurt, Austria _______________________________________________ Xen-community mailing list Xen-community@lists.xensource.com http://lists.xensource.com/mailman/listinfo/xen-community