A resource and partition manager virtualizes interrupts without using any additional hardware in a way that does not disturb the interrupt processing model of operating systems running on a logical partition. In other words, the resource and partition manager supports virtual interrupts in a logically partitioned computer system that may include share processors with no changes to a logical partition's operating system. A set of virtual interrupt registers is created for each virtual processor in the system. The resource and partition manager uses the virtual interrupt registers to process interrupts for the corresponding virtual processor. In this manner, from the point of view of the operating system, the interrupt processing when the operating system is running in a logical partition that may contain shared processors and virtual interrupts is no different that the interrupt processing when the operating system is running in computer system that only contains dedicated processor partitions.