Avoiding cache-line sharing in virtual machines can be implemented in a system running a host and multiple guest operating systems. The host facilitates hardware access by a guest operating system and oversees memory access by the guest. Because cache lines are associated with memory pages that are spaced at regular intervals, the host can direct guest memory access to only select memory pages, and thereby restrict guest cache use to one or more cache lines. Other guests can be restricted to different cache lines by directing memory access to a separate set of memory pages.