MICRO-INSTRUCTION CACHE ANNOTATIONS TO INDICATE SPECULATIVE SIDE-CHANNEL RISK CONDITION FOR READ INSTRUCTIONS

摘要

An apparatus (2) has processing circuitry to process micro-operations, the processing circuitry supporting speculative processing of read micro-operations for reading data from a memory system. A cache (6, 8) is provided to cache the micro-operations or instructions decoded to generate the micro-operations. Profiling circuitry (40) annotates at least one cached micro-operation or instruction with annotation information depending on analysis of whether a read micro-operation satisfies a speculative side-channel condition indicative of a risk of information leakage if the read micro-operation is processed speculatively. The processing circuitry (12, 14) determines whether to trigger a speculative side-channel mitigation measure depending on the annotation information stored in the cache (6, 8).