I/O to unpinned memory supporting memory overcommit and live migration of virtual machines

Systems and methods of error handling in a network interface card (NIC) are provided. For a data packet destined for a local virtual machine (VM), if the NIC cannot determine a valid translation memory address for a virtual memory address in a buffer descriptor from a receive queue of the VM, the NIC can retrieve a backup buffer descriptor from a hypervisor queue, and store the packet in a host memory location indicated by an address in the backup buffer descriptor. For a transmission request from a local VM, if the NIC cannot determine a valid translated address for a virtual memory address in the packet descriptor from a transmit queue of the VM, the NIC can send a message to a hypervisor backup queue, and generate and transmit a data packet based on data in a memory page reallocated by the hypervisor.