1. A computer program product comprising: a non-transitory computer-readable storage medium having computer-readable program code embodied therewith, the computer-readable program code executable by one or more computer processors to perform an operation comprising: receiving a request from a first application to a coherent accelerator to perform an I/O operation within a kernel context, wherein the coherent accelerator shares virtual memory with the one or more computer processors, wherein the request specifies a first effective address of a local effective address space distinct to the first application, and wherein the first effective address specifies a location in the local effective address space of the kernel context and a first effective segment identifier, remapping the first effective address to a second effective address in a global effective address space shared by the first application and at least a second application, wherein the second effective address specifies a location in the global effective address space of the kernel context and a second effective segment identifier, determining, by a lookup using the second effective segment identifier on a page table and a shared segment table, a virtual address that maps to a virtual address space within the kernel context, and translating the virtual address to a physical memory address.