US Patent 10054977 Controlling system clocks in virtual machines

Managing system clocks of virtual machines. A host system clock value of a host system clock of a host system is obtained, and a virtual machine system clock value of a system clock of a virtual machine managed by the host system is determined. The determining of the virtual machine system clock value includes using the host system clock value and a system clock adjustment value. The system clock of the virtual machine is adjusted using the virtual machine system clock value.