Rethinking the Linux cloud stack for confidential VMs
a day ago
- #virtualization
- #confidential-computing
- #cloud-security
- Confidential computing aims to protect VM memory from hypervisors, balancing performance and security.
- Isolation in cloud computing is achieved through hardware mechanisms, hypervisors, and user-space controls like cgroups and namespaces.
- Hardware offloading improves I/O performance but introduces security trade-offs by bypassing OS checks.
- Technologies like AMD's SEV-TIO and TDISP enable secure device interaction within confidential VMs.
- Secure Boot and remote attestation (e.g., RATS) ensure platform integrity but add boot-time overhead.
- Confidential VMs face performance hits from DRAM encryption and memory page acceptance processes.
- Scalability is limited by hardware constraints like ASIDs, potentially underutilizing multicore processors.
- Live migration in confidential VMs requires re-attestation and verification of memory integrity.
- Open architectures like RISC-V may offer auditable hardware solutions to reduce trust in third parties.
- Confidential computing shifts trust from cloud providers to hardware manufacturers, raising concerns about firmware vulnerabilities.