Virtual Machine-Preserving Host Updates

A computer system, comprising:

• a processor;
• system memory;
• one or more computer-readable storage media having stored thereon computer-executable instructions that, when executed by the processor, causes the processor to perform a method for updating a host operating system, the processor operating to:
• load an updated host operating system to the system memory;
• suspend virtual machines running on the computer system;
• store an allocation map and state for each of the virtual machines to the system memory;
• shut down the active host operating system;
• transfer execution from the active host operating system to a loader;
• load a kernel of updated host operating system into the system memory via the loader;
• initialize the updated host operating system;
• load the allocation map and state for each of the virtual machines;
• and
• resume operation of the virtual machines by the updated host operating system.

A computer program product for implementing a method for updating a host operating system, the computer program product comprising one or more computer-readable storage media having stored thereon computer-executable instructions that, when executed by one or more processors of a computer system, cause the computer system to perform the method comprising:

• receiving an updated host operating system;
• suspending all virtual machines running on the computer system;
• recording an allocation map and state for each of the virtual machines;
• transferring execution from the active host operating system to a loader;
• reading a kernel of updated host operating system into RAM via the loader;
• loading the allocation map and state for each of the virtual machines;
• and
• resuming operation of the virtual machines by the updated host operating system.