一句话：提出核心隔离的机密虚拟机，通过纯软件修改让互不信任代码不共享物理核，从而消除同核侧信道和瞬态执行漏洞。
机密虚拟机（Intel TDX、AMD SEV、Arm CCA）承诺抵御 hypervisor 级攻击者，但反复出现的瞬态执行漏洞和 CPU bug 使其失效。根源是需在互不信任实体间多路复用 CPU 核及其复杂微架构状态，且由不可信 hypervisor 控制多路复用。本文提出 core-gapped 机密虚拟机：纯软件修改，确保互不信任代码不共享同一个核，从而从 guest TCB 中移除同核侧信道和瞬态执行漏洞。作者构建 Arm 原型并评估性能，显示 core-gapping 性能可与非机密虚拟机竞争，且避免共享核带来的更好局部性甚至能提升 CPU 密集型负载性能。
Confidential VMs on platforms such as Intel TDX, AMD SEV and Arm CCA promise greater security for cloud users against even a hypervisor-level attacker, but this promise has been shattered by repeated transient-execution vulnerabilities and CPU bugs. At the root of this problem lies the need to multiplex CPU cores with all their complex microarchitectural state among distrusting entities, with an untrusted hypervisor in control of the multiplexing. We propose core-gapped confidential VMs, a set of software-only modifications that ensure that no distrusting code shares a core, thus removing all same-core side-channels and transient-execution vulnerabilities from the guest's TCB. We present an Arm-based prototype along with a performance evaluation showing that, not only does core-gapping offer performance competitive with non-confidential VMs, the greater locality achieved by avoiding shared cores can even improve performance for CPU-intensive workloads.