US 11,797,713 B2
Systems and methods for dynamic control of a secure mode of operation in a processor
Debapriya Chatterjee, Austin, TX (US); Christian Zoellin, Weinstadt (DE); Bradly George Frey, Austin, TX (US); and Brian W. Thompto, Austin, TX (US)
Assigned to International Business Machines Corporation, Armonk, NY (US)
Filed by International Business Machines Corporation, Armonk, NY (US)
Filed on Dec. 16, 2020, as Appl. No. 17/124,007.
Prior Publication US 2022/0188464 A1, Jun. 16, 2022
Int. Cl. G06F 21/74 (2013.01); G06F 9/38 (2018.01)
CPC G06F 21/74 (2013.01) [G06F 9/3818 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method of changing a mode of operation in a processor without rebooting the processor, the method comprising:
initiating a change in configuration in a processor from a performance mode to a secure mode for a control aspect in a privilege level;
determining whether the bit for the control aspect in the privilege level is set in a Privilege Entry (PRVS) register field to secure mode;
if the bit for the control aspect in the privilege level in the PRVS register field is not set to secure mode, then setting the bit for the control aspect in the privilege level in the PRVS register field to secure mode, thereby enabling the secure mode in the processor for the control aspect in the privilege level;
determining whether to enforce secure mode for the control aspect on lower privilege levels; and
if it is determined not to enforce secure mode for the control aspect on lower privilege levels then the method of changing to the secure mode for the control aspect in the privilege level is complete.