Configurable fine-grain protection for multicore processor virtualization

Abstract

Multicore architectures, with their abundant on-chip resources, are effectively collections of systems-on-a-chip. The protection system for these architectures must support multiple concurrently executing operating systems (OSes) with different needs, and manage and protect the hardware's novel communication mechanisms and hardware features. Traditional protection systems are insufficient; they protect supervisor from user code, but typically do not protect one system from another, and only support fixed assignment of resources to protection levels. In this paper, we propose an alternative to traditional protection systems which we call configurable fine-grain protection (CFP). CFP enables the dynamic assignment of in-core resources to protection levels. We investigate how CFP enables different system software stacks to utilize the same configurable protection hardware, and how differing OSes can execute at the same time on a multicore processor with CFP. As illustration, we describe an implementation of CFP in a commercial multicore, the TILE64 processor.

Reducing world switches in virtualized environment with flexible cross-world calls

“…Deciding whether a cross-world call is allowed or not resembles deciding a capability in capability-based systems [40,42]. Traditional capability-based systems usually have to make a tradeoff between flexibility and performance when deciding the types of capabilities and the form of unforgeable token (see Table 2).…”