EFFICIENT AND SECURE MEMORY ALLOCATION IN VIRTUALIZED COMPUTER SYSTEMS

A system and method for efficient and secure memory allocation in virtualized systems. A hypervisor receives, from a first virtual machine (VM), a message specifying a page of memory accessible to the first VM. The hypervisor determines that the page is not accessible to other VMs, adds an identifier identifying the page to a set of free page identifiers, and associates the identifier with the first VM. The hypervisor receives a page allocation request from a second VM, and in response attempts to locate an identifier associated with the second VM in the set of free page identifiers. Responsive to a successful attempt, the hypervisor allocates to the second VM a first page of memory corresponding to the located identifier, without clearing the first page. Responsive to an unsuccessful attempt, the hypervisor clears a second page of memory and allocates the cleared second page to the second VM.