Memory is reserved in a virtualized computing environment for graphics processing of each child partition in the computing environment. A video memory controller can identify video settings for child partitions. The video memory controller can determine an amount of memory for graphics processing for a child partition based on the video settings for that child partition. The video memory can also request an amount of memory to be reserved for that child partition based on the calculated amount of memory. Reserving memory for graphics processing of child partitions in this way allows for a sufficient amount of memory to be reserved for a child partition without wasting memory resources by reserving significantly more memory than is needed for the child partition.