Increased efficiency obfuscated logical-to-physical map management
Devices and techniques for efficient obfuscated logical-to-physical mapping are described herein. For example, activity corresponding to obfuscated regions of an L2P map for a memory device can be tracked. A record of discontinuity between the obfuscated regions and L2P mappings resulting from the activity can be updated. The obfuscated regions can be ordered based on a level of discontinuity from the record of discontinuity. When an idle period is identified, an obfuscated region from the obfuscated regions is selected and refreshed based on the ordering.
1. A memory device that implements obfuscated logical-to-physical (L2P) map management, the memory device comprising:
processing circuitry; and
storage that includes instructions, the instructions, when executed by the processing circuitry, configured the processing circuitry to:
track activity in a memory device corresponding to obfuscated regions of an L2P map for the memory device that is stored on the memory device;
update a record of discontinuity between the obfuscated regions and L2P mappings resulting from the activity;
identify an idle period;
order the obfuscated regions based on a level of discontinuity from the record of discontinuity; and
refresh, in response to the idle period, an obfuscated region from the obfuscated regions selected based on the ordering.
2. The memory device of claim 1 , wherein, to refresh the obfuscated region, the instructions configure the processing circuitry to:
obfuscate a sub-region of current L2P mappings to create a new obfuscated sub-region; and
store the new obfuscated sub-region in place of a corresponding sub-region for the obfuscated region.
3. The memory device of claim 1 , wherein the record of discontinuity tracks counts of deviations between current L2P mappings and L2P mappings represented by the obfuscated region.
4. The memory device of claim 3 , wherein, to update the record of discontinuity, the instructions configure the processing circuitry to increment a counter for a sub-region in response to writing of a logical address or changing of a physical address.
5. The memory device of claim 3 , wherein the record of discontinuity is a map in which a cell corresponds to a portion of an obfuscated region and a value in the cell indicates whether the portion has changed.
6. The memory device of claim 1 , wherein, to update the record of discontinuity between the obfuscated regions and L2P mappings, the instructions configure the processing circuitry to track a rate of change in the discontinuity; and
wherein, to order the obfuscated regions based on the level of discontinuity, the instructions configure the processing circuitry to apply an inverse ordering based on the rate.
7. The memory device of claim 1 , wherein the instructions configure the processing circuitry to maintain a record of host activity with respect to the obfuscated regions;
wherein, to order the obfuscated regions, the instructions configure the processing circuitry to use the host activity.
8. The memory device of claim 7 , wherein, to maintain a record of host activity, the instructions configure the processing circuitry to track which of the obfuscated regions the host has.
9. A method for obfuscated logical-to-physical (L2P) map management, the method comprising:
tracking activity in a memory device corresponding to obfuscated regions of an L2P map for the memory device that is stored on the memory device;
updating a record of discontinuity between the obfuscated regions and L2P mappings resulting from the activity;
identifying an idle period;
ordering the obfuscated regions based on a level of discontinuity from the record of discontinuity; and
refreshing, in response to the idle period, an obfuscated region from the obfuscated regions selected based on the ordering.
10. The method of claim 9 , wherein refreshing the obfuscated region includes:
obfuscating a sub-region of current L2P mappings to create a new obfuscated sub-region; and
storing the new obfuscated sub-region in place of a corresponding sub-region for the obfuscated region.
11. The method of claim 9 , wherein the record of discontinuity tracks counts of deviations between current L2P mappings and L2P mappings represented by the obfuscated region.
12. The method of claim 11 , wherein updating the record of discontinuity includes incrementing a counter for a sub-region in response to writing of a logical address or changing of a physical address.
13. The method of claim 11 , wherein the record of discontinuity is a map in which a cell corresponds to a portion of an obfuscated region and a value in the cell indicates whether the portion has changed.
14. The method of claim 9 , wherein updating the record of discontinuity between the obfuscated regions and L2P mappings includes tracking a rate of change in the discontinuity; and
wherein ordering the obfuscated regions based on the level of discontinuity includes applying an inverse ordering based on the rate.
15. The method of claim 9 , comprising maintaining a record of host activity with respect to the obfuscated regions;
wherein ordering the obfuscated regions includes using the host activity.
16. The method of claim 15 , wherein maintaining a record of host activity includes tracking which of the obfuscated regions the host has.
17. A non-transitory machine-readable medium including instructions to implement obfuscated logical-to-physical (L2P) map management, the instructions, when executed by processing circuitry, cause the processing circuitry to perform operations comprising:
tracking activity in a memory device corresponding to obfuscated regions of an L2P map for the memory device that is stored on the memory device;
updating a record of discontinuity between the obfuscated regions and L2P mappings resulting from the activity;
identifying an idle period;
ordering the obfuscated regions based on a level of discontinuity from the record of discontinuity; and
refreshing, in response to the idle period, an obfuscated region from the obfuscated regions selected based on the ordering.
18. The non-transitory machine-readable medium of claim 17 , wherein refreshing the obfuscated region includes:
obfuscating a sub-region of current L2P mappings to create a new obfuscated sub-region; and
storing the new obfuscated sub-region in place of a corresponding sub-region for the obfuscated region.
19. The non-transitory machine-readable medium of claim 17 , wherein the record of discontinuity tracks counts of deviations between current L2P mappings and L2P mappings represented by the obfuscated region.
20. The non-transitory machine-readable medium of claim 19 , wherein updating the record of discontinuity includes incrementing a counter for a sub-region in response to writing of a logical address or changing of a physical address.
21. The non-transitory machine-readable medium of claim 19 , wherein the record of discontinuity is a map in which a cell corresponds to a portion of an obfuscated region and a value in the cell indicates whether the portion has changed.
22. The non-transitory machine-readable medium of claim 17 , wherein updating the record of discontinuity between the obfuscated regions and L2P mappings includes tracking a rate of change in the discontinuity; and
wherein ordering the obfuscated regions based on the level of discontinuity includes applying an inverse ordering based on the rate.
23. The non-transitory machine-readable medium of claim 17 , wherein the operations comprise maintaining a record of host activity with respect to the obfuscated regions;
wherein ordering the obfuscated regions includes using the host activity.
24. The non-transitory machine-readable medium of claim 23 , wherein maintaining a record of host activity includes tracking which of the obfuscated regions the host has.