Software visible and controllable lock-stepping with configurable logical processor granularities

A computing system, comprising:

• a) a processor, the processor comprising:
• (i) first model specific register (MSR) space to specify a granularity of a processing entity of a lock-step group of processing entities;
• (ii) second MSR space to specify whether the processing entity is an active or shadow processing entity of the lock-step group of processing entities;
• (iii) third MSR space to indicate that the lock-step group is active;
• wherein, the first MSR space, the second MSR space and the third MSR space is accessible to at least one of a virtual machine monitor, an operating system and an application software program;
• b) a main memory coupled to the processor;
• and,
• c) a network interface.

A method, comprising:

• executing software at a level above a BIOS level, the executing of the software comprising:
• recognizing imminent execution of corruption sensitive program code;
• identifying active and shadow processing entities to execute the corruption sensitive program code in lock-step;
• before executing the corruption sensitive program code in lock-step, saving state information of a shadow processing entity of the active and shadow processing entities;
• executing the corruption sensitive program code in lock-step with the active and shadow processing entities;
• and,
• after lock-step execution of the corruption sensitive program code by the active and shadow processing entities is finished, restoring the shadow processing entity with the state information.

A processor comprising:

• a) model specific register space that is visible to software above a BIOS level, the model specific register space to specify a granularity of a processing entity of a lock-step group;
• and,
• b) logic circuitry to support dynamic entry/exit of the lock-step group's processing entities to/from lock-step mode including i) and ii) below:
• i) termination of lock-step execution by the processing entities before the program code to be executed in lock-step is fully executed;
• and,
• ii) as part of the exit from the lock-step mode, restoration of a state of a shadow processing entity of the processing entities as the state existed before the shadow processing entity entered the lock-step mode and began lock-step execution of the program code.