1. A method, comprising: receiving an input/output (I/O) request, the I/O request instructing a transfer of data between a first portion of a main memory of a computing system and an I/O device; receiving a cancellation request to cancel the I/O request; in response to the cancellation request, preventing an application executing on the computing system from accessing the first portion of the main memory, while leaving the first portion of the main memory accessible to the I/O device; prior to the cancellation request being received, mapping a virtual memory of the application to the first portion of the main memory; and subsequent to the cancellation request being received, reassigning the virtual memory of the application from the first portion of the main memory to a second portion of the main memory.