Apparatuses and methods for speculative execution side channel mitigation

US11635965B2 · kind B2 · utility

Assignee

• Intel Corporation · US

Inventors

• Jason W. Brandt · Austin, US
• Deepak Gupta · Delhi, IN
• Rodrigo Branco · Hillsboro, US
• Joseph Nuzman · Aberdeen, US
• Robert S. Chappell · Portland, US
• Sergiu D. Ghetie · Hillsboro, US
• Wojciech Stefan Powiertowski · Kirkland, US
• Jared W. Stark, IV · Portland, US
• Ariel Sabba · Carmiel, IL
• Scott J. Cape · Portland, US
• Hisham Shafi · Beer Sheva, IL
• Lihu Rappoport · Haifa, IL
• Yair Berger · Pardes Hana-Karkur, IL
• Scott P. Bobholz · Bolton, US
• Gilad Holzstein · Haifa, IL
• Sagar V. Dalvi · Hillsboro, US
• Yogesh Bijlani · Hillsboro, US

Key dates

• Filing date: Oct 31, 2018
• Grant date: Apr 25, 2023
• Expiry date: Oct 31, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G06F9/3842
• WIPO field: Computer technology
• WIPO sector: Electrical engineering

Abstract

Methods and apparatuses relating to mitigations for speculative execution side channels are described. Speculative execution hardware and environments that utilize the mitigations are also described. For example, three indirect branch control mechanisms and their associated hardware are discussed herein: (i) indirect branch restricted speculation (IBRS) to restrict speculation of indirect branches, (ii) single thread indirect branch predictors (STIBP) to prevent indirect branch predictions from being controlled by a sibling thread, and (iii) indirect branch predictor barrier (IBPB) to prevent indirect branch predictions after the barrier from being controlled by software executed before the barrier.