Secure Virtualization and Multicore Platforms State-of-the-Art report

SVaM

Challenges in real-time virtualization and predictable cloud computing

Cloud computing and virtualization technology have revolutionized general-purpose computing applications in the past decade. The cloud paradigm offers advantages through reduction of operation costs, server consolidation, flexible system configuration and elastic resource provisioning. However, despite the success of cloud computing for general-purpose computing, existing cloud computing and virtualization technology face tremendous challenges in supporting emerging soft real-time applications such as online video streaming, cloud-based gaming, and telecommunication management. These applications demand real-time performance in open, shared and virtualized computing environments. This paper identifies the technical challenges in supporting real-time applications in the cloud, surveys recent advancement in real-time virtualization and cloud computing technology, and offers research directions to enable cloud-based real-time applications in the future

Transparent dynamic instrumentation

Process virtualization provides a virtual execution environment within which an unmodified application can be monitored and controlled while it executes. The provided layer of control can be used for purposes ranging from sandboxing to compatibility to profiling. The additional operations required for this layer are performed clandestinely alongside regular program execution. Software dynamic instrumentation is one method for implementing process virtualization which dynamically instruments an application such that the application's code and the inserted code are interleaved together. DynamoRIO is a process virtualization system implemented using software code cache techniques that allows users to build customized dynamic instrumentation tools. There are many challenges to building such a runtime system. One major obstacle is transparency. In order to support executing arbitrary applications, DynamoRIO must be fully transparent so that an application cannot distinguish between running inside the virtual environment and native execution. In addition, any desired extra operations for a particular tool must avoid interfering with the behavior of the application. Transparency has historically been provided on an ad-hoc basis, as a reaction to observed problems in target applications. This paper identifies a necessary set of transparency requirements for running mainstream Windows and Linux applications. We discuss possible solutions to each transparency issue, evaluate tradeoffs between different choices, and identify cases where maintaining transparency is not practically solvable. We believe this will provide a guideline for better design and implementation of transparent dynamic instrumentation, as well as other similar process virtualization systems using software code caches

Thin Hypervisor-Based Security Architectures for Embedded Platforms

Virtualization has grown increasingly popular, thanks to its benefits of isolation, management, and utilization, supported by hardware advances. It is also receiving attention for its potential to support security, through hypervisor-based services and advanced protections supplied to guests. Today, virtualization is even making inroads in the embedded space, and embedded systems, with their security needs, have already started to benefit from virtualization’s security potential. In this thesis, we investigate the possibilities for thin hypervisor-based security on embedded platforms. In addition to significant background study, we present implementation of a low-footprint, thin hypervisor capable of providing security protections to a single FreeRTOS guest kernel on ARM. Backed by performance test results, our hypervisor provides security to a formerly unsecured kernel with minimal performance overhead, and represents a first step in a greater research effort into the security advantages and possibilities of embedded thin hypervisors. Our results show that thin hypervisors are both possible and beneficial even on limited embedded systems, and sets the stage for more advanced investigations, implementations, and security applications in the future

Characterizing and Mitigating Virtual Machine Interference in Public Clouds.

This dissertation studies the mitigation of the performance and security interference between guest virtual machines (VMs) in public clouds. The goals are to characterize the impact of VM interference, uncover the root cause of the negative impact, and design novel techniques to mitigate such impact. The central premise of this dissertation is that by identifying the shared resources that cause the VM interference and by exploiting the properties of the workloads that share these resources with adapted scheduling policies, public cloud services can reduce conflicts of resource usage between guests and hence mitigate their interference. Current techniques for conflict reduction and interference mitigation overlook the virtualization semantic gap between the cloud host infrastructure and guest virtual ma- chines and the unique challenges posed by the multi-tenancy service model necessary to support public cloud services. This dissertation deals with both performance and security interference problems. It characterizes the impact of VM interference on inter-VM network latency using live measurements in a real public cloud and studies the root cause of the negative impact with controlled experiments on a local testbed. Two methods of improving the inter-VM net- work latency are explored. The first approach is a guest-centric solution that exploits the properties of application workloads to avoid interference without any support from the underlying host infrastructure. The second approach is a host-centric solution that adapts the scheduling policies for the contented resources that cause the interference without guest cooperation. Similarly, the characteristics of cache-based cross-VM attacks are studied in detail using both live cloud measurements and testbed experiments. To mitigate this security interference, a partition-based VM scheduling system is designed to reduce the effectiveness of these cache-based attacks.PhDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107111/1/yunjing_1.pd

Virtualization of Micro-architectural Components Using Software Solutions

Cloud computing has become a dominant computing paradigm in the information technology industry due to its flexibility and efficiency in resource sharing and management. The key technology that enables cloud computing is virtualization. Essential requirements in a virtualized system where several virtual machines (VMs) run on a same physical machine include performance isolation and predictability. To enforce these properties, the virtualization software (called the hypervisor) must find a way to divide physical resources (e.g., physical memory, processor time) of the system and allocate them to VMs with respect to the amount of virtual resources defined for each VM. However, modern hardware have complex architectures and some microarchitectural-level resources such as processor caches, memory controllers, interconnects cannot be divided and allocated to VMs. They are globally shared among all VMs which compete for their use, leading to contention. Therefore, performance isolation and predictability are compromised. In this thesis, we propose software solutions for preventing unpredictability in performance due to micro-architectural components. The first contribution is called Kyoto, a solution to the cache contention issue, inspired by the polluters pay principle. A VM is said to pollute the cache if it provokes significant cache replacements which impact the performance of other VMs. Henceforth, using the Kyoto system, the provider can encourage cloud users to book pollution permits for their VMs. The second contribution addresses the problem of efficiently virtualizing NUMA machines. The major challenge comes from the fact that the hypervisor regularly reconfigures the placement of a VM over the NUMA topology. However, neither guest operating systems (OSs) nor system runtime libraries (e.g., HotSpot) are designed to consider NUMA topology changes at runtime, leading end user applications to unpredictable performance. We presents eXtended Para-Virtualization (XPV), a new principle to efficiently virtualize a NUMA architecture. XPV consists in revisiting the interface between the hypervisor and the guest OS, and between the guest OS and system runtime libraries so that they can dynamically take into account NUMA topology changes

Trusted data path protecting shared data in virtualized distributed systems

When sharing data across multiple sites, service applications should not be trusted automatically. Services that are suspected of faulty, erroneous, or malicious behaviors, or that run on systems that may be compromised, should not be able to gain access to protected data or entrusted with the same data access rights as others. This thesis proposes a context flow model that controls the information flow in a distributed system. Each service application along with its surrounding context in a distributed system is treated as a controllable principal. This thesis defines a trust-based access control model that controls the information exchange between these principals. An online monitoring framework is used to evaluate the trustworthiness of the service applications and the underlining systems. An external communication interception runtime framework enforces trust-based access control transparently for the entire system.Ph.D.Committee Chair: Karsten Schwan; Committee Member: Douglas M. Blough; Committee Member: Greg Eisenhauer; Committee Member: Mustaque Ahamad; Committee Member: Wenke Le

Real-Time Sensor Networks and Systems for the Industrial IoT

The Industrial Internet of Things (Industrial IoT—IIoT) has emerged as the core construct behind the various cyber-physical systems constituting a principal dimension of the fourth Industrial Revolution. While initially born as the concept behind specific industrial applications of generic IoT technologies, for the optimization of operational efficiency in automation and control, it quickly enabled the achievement of the total convergence of Operational (OT) and Information Technologies (IT). The IIoT has now surpassed the traditional borders of automation and control functions in the process and manufacturing industry, shifting towards a wider domain of functions and industries, embraced under the dominant global initiatives and architectural frameworks of Industry 4.0 (or Industrie 4.0) in Germany, Industrial Internet in the US, Society 5.0 in Japan, and Made-in-China 2025 in China. As real-time embedded systems are quickly achieving ubiquity in everyday life and in industrial environments, and many processes already depend on real-time cyber-physical systems and embedded sensors, the integration of IoT with cognitive computing and real-time data exchange is essential for real-time analytics and realization of digital twins in smart environments and services under the various frameworks’ provisions. In this context, real-time sensor networks and systems for the Industrial IoT encompass multiple technologies and raise significant design, optimization, integration and exploitation challenges. The ten articles in this Special Issue describe advances in real-time sensor networks and systems that are significant enablers of the Industrial IoT paradigm. In the relevant landscape, the domain of wireless networking technologies is centrally positioned, as expected