On making xen detect hypercalls and memory accesses for simulating virtualization-enabled processors
Swapneel C. Mhatre, Priya Chandran · 2020
Due to the widespread use of cloud-based systems that are shared by multiple users, new processors are enhanced for security in virtualization. However, it is a challenging task to develop simulators for such processors, mainly, due to the lack of relevant information at the application level for computing performance parameters. This paper proposes a methodology to extract the required information from the hypervisor and transfer it to the hardware-based simulator for simulation of such processors. The paper proposes an approach to detect hypercalls made by the guest operating system during the execution of the guest application program on Xen hypervisor. This paper considers five hypercalls, viz., mmu_update, memory_op, update_va_mapping, grant_table_op and mmuext_op. The results show that for the guest application executed, among these five hypercalls, mmu_update is called the maximum number of times, while memory_op is called the minimum number of times. The paper also proposes an approach to signal the memory accesses by Xen on the communications (COM) port. This signal is observed on the cathode ray oscilloscope (CRO) and may be utilized for simulation. This research is valuable as it concludes that virtualization-enabled processors may be effectively simulated by extracting the required information from the hypervisor.