Abstract: One embodiment of the present invention provides a system that facilitates user-mode system-level virtualization in a mobile device. During operation, a hypervisor intercepts a virtual machine's attempt to access a privileged resource. The hypervisor manages the virtual machine and runs on a host system in a user mode. Furthermore, the hypervisor emulates the privileged resource using a user-mode system call provided by the host system. In addition, the hypervisor provides access to the emulated privileged resource to the virtual machine, thereby allowing the virtual machine to operate with the emulated privileged resource without directly accessing actual privileged resources on the host system.

Abstract: Methods for providing shadow page tables that virtualize processor memory protection. In one embodiment, virtualization software maintains the following: (a) a mapping ? from guest domain identifier to a set of shadow L2 page tables that back guest L1 sections marked with a domain identifier; and (b) with each such shadow L2 page table, a set ? of back-pointers to “potentially referencing” shadow L1 descriptors.

Abstract: Machine memory fragmentation in a computer system having a host operating system and virtual machine running on a hypervisor hosted by the host operating system is reduced by having the hypervisor identify and release those machine memory pages that are more likely than others to reduce the fragmented state of the host machine memory.

Abstract: A computing device employs a cooperative memory management technique to dynamically balance memory resources between host and guest systems running therein. According to this cooperative memory management technique, memory that is allocated to the guest system is dynamically adjusted up and down according to a fairness policy that takes into account various factors including the relative amount of readily freeable memory resources in the host and guest systems and the relative amount of memory allocated to hidden applications in the host and guest systems.

Abstract: A computing device employs a cooperative memory management technique to dynamically balance memory resources between host and guest systems running therein. According to this cooperative memory management technique, memory that is allocated to the guest system is dynamically adjusted up and down according to a fairness policy that takes into account various factors including the relative amount of readily freeable memory resources in the host and guest systems and the relative amount of memory allocated to hidden applications in the host and guest systems.

Abstract: Methods for providing shadow page tables that virtualize processor memory protection. In one embodiment, two shadow L2 page tables are maintained for each section, for example, each 1 MB section, of guest address space covered by a shadow L1 descriptor.

Abstract: In a computing system including a processor and virtualization software including a guest operating system (OS) that utilizes a guest domain access control register (DACR) containing domain access information and guest page tables including first level page tables (L1 page tables) and second level page tables (L2 page tables), which guest page tables contain: (a) domain identifiers used to obtain domain access information from the guest DACR and (b) access permission information, wherein the domain access information and the access permission information are combined to provide an effective guest access permission, in accordance with one embodiment, a method for providing shadow page tables and processor DACR settings that virtualize processor memory protection includes: the virtualization software providing a shadow page table wherein: (a) domain identifiers in the shadow page table are used to identify domain access information in the processor DACR that are mapped from the domain access information in the

Abstract: Methods for providing shadow page tables that virtualize processor memory protection. In one embodiment, virtualization software maintains the following: (a) a mapping ? from guest domain identifier to a set of shadow L2 page tables that back guest L1 sections marked with a domain identifier; and (b) with each such shadow L2 page table, a set ? of back-pointers to “potentially referencing” shadow L1 descriptors.