A method for sharing memory between a central processing unit (CPU) and an input/output (I/O) device of a computing device is described. The method may include creating an allocation of memory for the I/O device to operate on. The method includes detecting whether the allocation is not page-aligned, wherein an allocation is page-aligned when its base address and size be evenly divisible by the applicable page-size. The allocation may be successfully shared, even if not page-aligned, even if an operating system of the computing device doesn't support sharing of non-page-aligned allocations.