A computer system that supports virtualization may maintain multiple address spaces. Each guest operating system employs guest virtual addresses (GVAs), which are translated to guest physical addresses (GPAs). A hypervisor, which manages one or more guest operating systems, translates GPAs to root physical addresses (RPAs). A merged translation lookaside buffer (MTLB) caches translations between the multiple addressing domains, enabling faster address translation and memory access. The MTLB can be logically addressable as multiple different caches, and can be reconfigured to allot different spaces to each logical cache. Lookups to the caches of the MTLB can be selectively bypassed based on a control configuration and the attributes of a received address.