一句话：发现 AMD SEV 处理器的缓存刷新与内存争用侧信道，并提出两种 Reload+Reload 攻击。
论文针对多租户云中 AMD SEV/SEV-ES/SEV-SNP 加密虚拟机面临的信息泄露风险，发现了两种此前未知的侧信道：缓存刷新（cache flush）和内存争用（memory contention）。作者据此提出 Reload+Reload-flush-set（RRFS）与 Reload+Reload-memory-block（RRMB）两种攻击。在 SEV-SNP 保护虚拟机上，他们利用 RRFS 构建面向 Spectre 攻击的隐蔽信道，并用 RRMB 提取 AES-128 密钥。实验表明，与基于 Prime+Probe 的实现相比，RRFS 隐蔽信道具有更强的抗噪性和更高容量，且攻击适用于 SEV-SNP 及更早版本。
To enhance the security of virtual machines (VMs) in multi-tenant cloud environments, AMD provides the Secure Encrypted Virtualization (SEV) extension to support encrypted VMs. We discovered two previously unknown side channels from AMD processors with SEV support: cache flush and memory contention side channels. Our findings apply to SEV-SNP and earlier versions of the technology (SEV and SEV-ES). We formulated two Reload+Reload (RR) attacks based on our two respective findings: Reload+Reload-flush-set (RRFS) and Reload+Reload-memory-block (RRMB). We demonstrated the effectiveness of the attacks against SEV-SNP protected VMs: we built a RRFS-based covert channel for a Spectre attack and used RRMB for extracting AES-128 secret keys. Compared to Prime+Probe-based implementations, our RRFS-based covert channel demonstrates superior noise resistance and higher capacity.