No abstract

As server consolidation using virtual machines (VMs)is carried out, software aging of virtual machine monitors (VMMs) is becoming critical. Performance degradation or crash failure of a VMM affects all VMs on it. To counteract such software aging, a proactive technique called software rejuvenation has been proposed. A typical example of rejuvenation is to reboot a VMM. However, simply rebooting a VMM is undesirable because that needs rebooting operating systems on all VMs. In this paper, we propose a new technique for fast rejuvenation of VMMs called the warm-VM reboot. The warm-VM reboot enables efficiently rebooting only a VMM by suspending and resuming VMs without accessing the memory images. To achieve this, we have developed two mechanisms: on-memory suspend/resume of VMs and quick reload of VMMs. The warm-VM reboot reduces the downtime and prevents the performance degradation due to cache misses after the reboot.

No abstract

Recently, containers are widely used to process big data in clouds. To prevent information leakage from containers, applications in containers can protect sensitive information using enclaves provided by Intel SGX. The memory of enclaves is encrypted by a CPU using its internal keys. However, the execution of SGX applications cannot be continued after the container running those applications is migrated. This is because enclave memory cannot be correctly decrypted at the destination host. This paper proposes MigSGX for enabling the continuous execution of SGX applications after container migration. Since the states of enclaves cannot be directly accessed from the outside, MigSGX securely invokes each enclave and makes it dump and load its state. At the dump time, each enclave re-encrypts its state using a CPU-independent key to protect sensitive information. For space-and time-efficiency, MigSGX saves and restores a large amount of enclave memory in a pipelined manner. We have implemented MigSGX in the Intel SGX SDK and CRIU and showed that pipelining could improve migration performance by up to 52%. The memory necessary for migration was reduced only to 0.15%. CCS CONCEPTS• Security and privacy → Virtualization and security; • Software and its engineering → Virtual memory.

No abstract