Do not predict – Recompute! How value recomputation can truly boost the performance of invisible speculation

Name: Do not predict – Recompute! How value recomputation can truly boost the performance of invisible speculation
Author: Sakalis, C., Chowdhury, Z., Wadle, S., Aktürk, İsmail, Ros, A., Sjalander, M., Kaxiras, S., Karpuzcu, U.

İsim	Do not predict – Recompute! How value recomputation can truly boost the performance of invisible speculation
Yazar	Sakalis, C., Chowdhury, Z., Wadle, S., Aktürk, İsmail, Ros, A., Sjalander, M., Kaxiras, S., Karpuzcu, U.
Basım Tarihi:	2021
Basım Yeri	- IEEE
Konu	Hardware security, Speculation, Recomputation
Tür	Belge
Dil	İngilizce
Dijital	Evet
Yazma	Hayır
Kütüphane:	Özyeğin Üniversitesi
Demirbaş Numarası	2-s2.0-85117451537
Kayıt Numarası	7812055f-c009-4063-9474-e332473e5a08
Lokasyon	Computer Science
Tarih	2021
Örnek Metin	Recent architectural approaches that address speculative side-channel attacks aim to prevent software from exposing the microarchitectural state changes of transient execution. The Delay-on-Miss technique is one such approach, which simply delays loads that miss in the L1 cache until they become non-speculative, resulting in no transient changes in the memory hierarchy. However, this costs performance, prompting the use of value prediction (VP) to regain some of the delay.However, the problem cannot be solved by simply introducing a new kind of speculation (value prediction). Value-predicted loads have to be validated, which cannot be commenced until the load becomes non-speculative. Thus, value-predicted loads occupy the same amount of precious core resources (e.g., reorder buffer entries) as Delay-on-Miss. The end result is that VP only yields marginal benefits over Delay-on-Miss.In this paper, our insight is that we can achieve the same goal as VP (increasing performance by providing the value of loads that miss) without incurring its negative side-effect (delaying the release of precious resources), if we can safely, non-speculatively, recompute a value in isolation (without being seen from the outside), so that we do not expose any information by transferring such a value via the memory hierarchy. Value Recomputation, which trades computation for data transfer was previously proposed in an entirely different context: to reduce energy-expensive data transfers in the memory hierarchy. In this paper, we demonstrate the potential of value recomputation in relation to the Delay-on-Miss approach of hiding speculation, discuss the trade-offs, and show that we can achieve the same level of security, reaching 93% of the unsecured baseline performance (5% higher than Delay-on-miss), and exceeding (by 3%) what even an oracular (100% accuracy and coverage) value predictor could do.
DOI	10.1109/SEED51797.2021.00021

Kaynağa git Özyeğin Üniversitesi

Aramaya Dön

Özyeğin Üniversitesi

Kaynağa git

Do not predict – Recompute! How value recomputation can truly boost the performance of invisible speculation

Yazar Sakalis, C., Chowdhury, Z., Wadle, S., Aktürk, İsmail, Ros, A., Sjalander, M., Kaxiras, S., Karpuzcu, U.

Basım Tarihi 2021

Basım Yeri - IEEE

Konu Hardware security, Speculation, Recomputation

Tür Belge

Dil İngilizce

Dijital Evet

Yazma Hayır

Kütüphane Özyeğin Üniversitesi

Demirbaş Numarası 2-s2.0-85117451537

Kayıt Numarası 7812055f-c009-4063-9474-e332473e5a08

Lokasyon Computer Science

Tarih 2021

Örnek Metin Recent architectural approaches that address speculative side-channel attacks aim to prevent software from exposing the microarchitectural state changes of transient execution. The Delay-on-Miss technique is one such approach, which simply delays loads that miss in the L1 cache until they become non-speculative, resulting in no transient changes in the memory hierarchy. However, this costs performance, prompting the use of value prediction (VP) to regain some of the delay.However, the problem cannot be solved by simply introducing a new kind of speculation (value prediction). Value-predicted loads have to be validated, which cannot be commenced until the load becomes non-speculative. Thus, value-predicted loads occupy the same amount of precious core resources (e.g., reorder buffer entries) as Delay-on-Miss. The end result is that VP only yields marginal benefits over Delay-on-Miss.In this paper, our insight is that we can achieve the same goal as VP (increasing performance by providing the value of loads that miss) without incurring its negative side-effect (delaying the release of precious resources), if we can safely, non-speculatively, recompute a value in isolation (without being seen from the outside), so that we do not expose any information by transferring such a value via the memory hierarchy. Value Recomputation, which trades computation for data transfer was previously proposed in an entirely different context: to reduce energy-expensive data transfers in the memory hierarchy. In this paper, we demonstrate the potential of value recomputation in relation to the Delay-on-Miss approach of hiding speculation, discuss the trade-offs, and show that we can achieve the same level of security, reaching 93% of the unsecured baseline performance (5% higher than Delay-on-miss), and exceeding (by 3%) what even an oracular (100% accuracy and coverage) value predictor could do.

DOI 10.1109/SEED51797.2021.00021