Abstract: A service management system prepares computing resources for use before a client requests the resource. For example, a service management system of a provider may restore an operating system image to a volume. The service management may then assign a processing resource to the volume to form a virtual machine. The service management system may cause the processing resource to finish preparation of the operating system on the volume. The service management system may disconnect the resulting staged volume from the processing resource. The staged volume may remain active in the low-latency data store and be added to a list of available staged volumes having the operating system. When a client requests a virtual machine having an operating system, the service management system may determine that the client receives the staged volume as part of the virtual machine to avoid the start-up costs of preparing a volume.

Abstract: A method and apparatus for testing a communication link are disclosed. In the method and apparatus, a routing loop is established between two devices connected by the communication link, and data is routed between the two devices over the communication link. One or more performance measures of the communication link are obtained based at least in part on the data routing. The one or more performance measures are then used to determine whether the communication link is defective.

Abstract: A virtual machine environment in which a hypervisor provides direct memory mapped access by a virtual guest to a physical memory device. The hypervisor prevents reading from, writing to, or both, any individual register or registers while allowing unrestricted access to other registers, and without raising any abnormal condition in the guest's execution environment. For example, in one embodiment, the hypervisor can apply memory access protection to a memory page containing a restricted register so that a fault condition can be raised. When an instruction is executed, the hypervisor can intercept the fault condition and emulate the faulting guest instruction. When the emulation accesses the restricted address, the hypervisor can selectively decide whether or not to perform the access.

Abstract: A proxy operating inside of a virtual machine that is responsible for receiving user-specified configuration information, such as credentials, and updating the configuration of the virtual machine with the user-specified values at the time of assigning the virtual machine to a user. Once the proxy updates the configuration of the virtual machine, the virtual machine is assigned the user that provided the user configuration information and the proxy can deactivate or uninstall itself from the virtual machine, such as by deleting all files, registry entries and other traces of execution.