Patent ID: 11934519
Assignee: VENTANA MICRO SYSTEMS INC.
Field: nan (nan)
Classification: CPC nan | IPC G

Claim 0:
1. A method of mitigating side channel attacks (SCAB) that exploit speculative store-to-load forwarding in a processor, the method comprising:
executing one or more store instructions, each of which has a store data address;
beginning execution of a load instruction, which has a load data address, before the one or more store instructions commit;
checking whether a record of the load instruction exists that predicts whether store data is available from an uncommitted store instruction for forwarding to the load instruction;
performing a partial or full comparison between the load instruction's virtual or physical data address and the virtual or physical data addresses of the one or more store instructions;
when (a) said record exists, (b) the comparison finds a data address match between the load instruction and one of the one or more store instructions, and (c) said one store instruction is a most recent store instruction, older than the load instruction, that has a matching data address, forwarding the store data of said one store instruction to the load instruction;, when no said record exists, refraining from forwarding and sourcing the load data from a cache, even when the comparison finds said data address match.