Host-resident translation layer validity check
Devices and techniques are disclosed herein for verifying host generated physical addresses at a memory device during a host-resident FTL mode of operation to ameliorate erroneous or potentially malicious access to the memory device.
1. A method comprising:
receiving a memory request from a host at a memory system, the memory request including a logical block address (LBA) associated with the host and a first physical address associated with the memory system;
identifying a second physical address from the LBA by referencing a cache of a logical-to-physical mapping table, the cache in volatile memory of the memory system;
determining that the second physical address does not match the physical address received in the memory request;
responsive to determining that the second physical address does not match the first physical address received in the memory request:
executing a memory operation associated with the memory request using the second physical address;
generating a response to the memory request;
incrementing a counter associated with the LBA;
determining that the counter exceeds a prespecified threshold; and
responsive to determining that the counter exceeds the prespecified threshold, returning the second physical address to the host with the request information and the LBA.
2. The method of claim 1 , including receiving an indication of a host-resident FTL mode of operation at the memory system.
3. The method of claim 1 , wherein the executing the memory operation includes reading information from flash memory of the memory system at the second physical address of the flash memory.
4. The method of claim 1 , further comprising:
receiving a second memory request with a second LBA and a third physical address;
determining that the second LBA is not within the cache of the logical-to-physical mapping table;
responsive to determining that the second LBA is not within the cache of the logical-to-physical mapping table, identifying a fourth physical address corresponding to the LBA from the logical-to-physical mapping table stored in flash memory;
determining that the fourth physical address matches the third physical address received in the second memory request; and
executing a memory operation associated with the second memory request using the third physical address.
5. The method of claim 1 , wherein the memory request is a read request and the request information is read data retrieved from flash memory of the memory system.
6. The method of claim 1 , wherein the memory request is a write request and the request information is an acknowledgment of completion of a write operation within flash memory of the memory system at the second physical address associated with the LBA.
7. A memory device comprising:
a cache configured to hold a portion of a mapping table of the memory device;
flash memory configured to store and retrieve user data of a host, and to store the mapping table of the memory device; and
a controller configured to perform operations comprising:
receiving a memory request from the host at a memory system, the memory request including a logical block address (LBA) associated with the host and a first physical address associated with the memory system;
identifying a second physical address from the LBA by referencing a cache of a logical-to-physical mapping table, the cache in volatile memory of the memory system;
determining that the second physical address does not match the first physical address received in the memory request;
responsive to determining that the second physical address does not match the physical address received in the memory request:
executing a memory operation associated with the memory request using the second physical address;
generating a response to the memory request;
incrementing a counter associated with the LBA;
determining that the counter exceeds a prespecified threshold; and
responsive to determining that the counter exceeds the prespecified threshold, returning the second physical address to the host with the request information and the LBA.
8. The memory device of claim 7 , wherein the operations further comprise receiving an indication of a performance boost mode of operation at the memory system prior to receiving the memory request including the LBA and first physical address.
9. The memory device of claim 7 ,
wherein the operations further comprise:
receiving a second memory request with a second LBA and a third physical address;
determining that the second LBA is not within the cache of the logical-to-physical mapping table;
responsive to determining that the second LBA is not within the cache of the logical-to-physical mapping table, identifying a fourth physical address corresponding to the LBA from the logical-to-physical mapping table stored in flash memory;
determining that the fourth physical address matches the third physical address received in the second memory request; and
executing a memory operation associated with the second memory request using the third physical address.
10. The memory device of claim 7 , wherein the memory request is a read request and the request information is read data retrieved from flash memory of the memory device.
11. The memory device of claim 7 , wherein the memory request is a write request and the request information is an acknowledgment of completion of a write operation within flash memory of the memory device at the second physical address associated with the LBA.
12. The memory device of claim 7 , wherein the flash memory includes NAND memory.
13. The memory device of claim 7 , wherein the cache is stored in dynamic random-access memory (DRAM).
14. The memory device of claim 7 , wherein the cache is stored in static random-access memory (SRAM).
15. The memory device of claim 7 , wherein the memory request is a program request and the request information is an acknowledgment of completion of a program operation within flash memory of the memory device at the second physical address associated with the LBA.
16. The memory device of claim 7 , wherein the memory request is an erase request and the request information is an acknowledgment of completion of an erase operation within flash memory of the memory device at the second physical address associated with the LBA.
17. The method of claim 1 , wherein the counter is incremented each time a physical address included in a memory request for the LBA does not match a physical address within the logical-to-physical mapping table.
18. The memory device of claim 7 , wherein the counter is incremented each time a physical address included in a memory request for the LBA does not match a physical address within the logical-to-physical mapping table.