A resource scheduler for managing a distribution of host physical memory (HPM) among a plurality of virtual machines (VMs) monitors usage by each of the VMs of respective guest physical memories (GPM) to determine how much of the HPM should be allocated to each of the VMs. On determining that an amount of HPM allocated to a source VM should be reallocated to a target VM, the scheduler sends allocation parameters to a balloon application executing in the source VM causing it to reserve and write a value to a guest virtual memory (GVM) location in the source VM. The scheduler identifies the HPM location that corresponds to the reserved GVM and allocates it to the target VM by mapping a guest physical memory location of the target VM to the HPM location.