Abstract: In an example, a computer system includes a hardware platform and a hypervisor executing on the hardware platform. The hypervisor includes a kernel and a plurality of user-space instances within a user-space above the kernel. Each user-space instance is isolated from each other user-space instance through namespaces. Each user-space instance includes resources confined by hierarchical resource groups. The computer system includes a plurality of virtual hypervisors, where each virtual hypervisor executes in a respective user-space instance of the plurality of user-space instances.

Abstract: Examples provide for automatically provisioning hosts in a cloud environment. A cloud daemon generates a cloud host-state configuration, for a given cloud instance of a host, stored on a cloud metadata service prior to first boot of the given cloud instance of the host. A first boot of a plurality of cloud instances of hosts is performed using a stateless, master boot image lacking host-specific configuration data. On completion of the first boot of a given cloud instance of a host, the cloud host-state configuration is installed on the master boot image to generate a self-configured boot image including host-specific configuration data for the given cloud instance of the host. A second boot is performed on the given cloud instance of the host by executing the self-configured boot image to automatically provision the given cloud instance of the host in the cloud environment.

Abstract: Examples provide for automatically provisioning hosts in a cloud environment. A cloud daemon generates a cloud host-state configuration, for a given cloud instance of a host, stored on a cloud metadata service prior to first boot of the given cloud instance of the host. A first boot of a plurality of cloud instances of hosts is performed using a stateless, master boot image lacking host-specific configuration data. On completion of the first boot of a given cloud instance of a host, the cloud host-state configuration is installed on the master boot image to generate a self-configured boot image including host-specific configuration data for the given cloud instance of the host. A second boot is performed on the given cloud instance of the host by executing the self-configured boot image to automatically provision the given cloud instance of the host in the cloud environment.

Abstract: A computer system provides a mechanism for assuring a safe, non-preemptible access to a private data area (PRDA) belonging to a CPU. PRDA accesses generally include obtaining an address of a PRDA and performing operations on the PRDA using the obtained address. Safe, non-preemptible access to a PRDA generally ensures that a context accesses the PRDA of the CPU on which the context is executing, but not the PRDA of another CPU. While a context executes on a first CPU, the context obtains the address of the PRDA. After the context is migrated to a second CPU, the context performs one or more operations on the PRDA belonging to the second CPU using the address obtained while the context executed on the first CPU. In another embodiment, preemption and possible migration of a context from one CPU to another CPU is delayed while a context executes non-preemptible code.

Abstract: An example method of initializing a plurality of processors in a hardware platform of computing device for use by system software executing on the hardware platform includes: parsing a descriptor table that has been loaded into memory from firmware to identify an original boot protocol for initializing at least one secondary processor of the plurality of processors; creating at least one mailbox structure in the memory associated with the at least one secondary processor; causing the at least one secondary processor to execute secondary processor initialization code stored in the memory, the secondary processor initialization code implementing a mailbox-based boot protocol that uses the at least one mailbox structure to initialize the at least one secondary processor; and modifying the descriptor table to identify the mailbox-based boot protocol for initializing the at least one secondary processor in place of the original boot protocol.

Abstract: Devices are emulated as PCI devices so that existing PCI drivers can be used for the devices. This is accomplished by creating a shim PCI device with a emulated PCI configuration space, accessed via a emulated PCI Extended Configuration Access Mechanism (ECAM) space which is emulated by accesses to trapped unbacked memory addresses. When system software accesses the PCI ECAM space to probe for PCI configuration data or program base address registers of the PCI ECAM space, an exception is raised and the exception is handled by a secure monitor that is executing at a higher privilege level than the system software. The secure monitor in handling the exception emulates the PCI configuration space access of the emulated PCI device corresponding to the ECAM address accessed, such that system software may discover the device and bind and appropriately configure a PCI driver to it with the right IRQ and memory base ranges.

Abstract: A computer system provides a mechanism for assuring a safe, non-preemptible access to a private data area (PRDA) belonging to a CPU. PRDA accesses generally include obtaining an address of a PRDA and performing operations on the PRDA using the obtained address. Safe, non-preemptible access to a PRDA generally ensures that a context accesses the PRDA of the CPU on which the context is executing, but not the PRDA of another CPU. While a context executes on a first CPU, the context obtains the address of the PRDA. After the context is migrated to a second CPU, the context performs one or more operations on the PRDA belonging to the second CPU using the address obtained while the context executed on the first CPU. In another embodiment, preemption and possible migration of a context from one CPU to another CPU is delayed while a context executes non-preemptible code.

Abstract: A computer system provides a mechanism for assuring a safe, non-preemptible access to a private data area (PRDA) belonging to a CPU. PRDA accesses generally include obtaining an address of a PRDA and performing operations on the PRDA using the obtained address. Safe, non-preemptible access to a PRDA generally ensures that a context accesses the PRDA of the CPU on which the context is executing, but not the PRDA of another CPU. While a context executes on a first CPU, the context obtains the address of the PRDA. After the context is migrated to a second CPU, the context performs one or more operations on the PRDA belonging to the second CPU using the address obtained while the context executed on the first CPU. In another embodiment, preemption and possible migration of a context from one CPU to another CPU is delayed while a context executes non-preemptible code.

Abstract: Examples provide for automatically provisioning hosts in a cloud environment. A cloud daemon generates a cloud host-state configuration, for a given cloud instance of a host, stored on a cloud metadata service prior to first boot of the given cloud instance of the host. A first boot of a plurality of cloud instances of hosts is performed using a stateless, master boot image lacking host-specific configuration data. On completion of the first boot of a given cloud instance of a host, the cloud host-state configuration is installed on the master boot image to generate a self-configured boot image including host-specific configuration data for the given cloud instance of the host. A second boot is performed on the given cloud instance of the host by executing the self-configured boot image to automatically provision the given cloud instance of the host in the cloud environment.

Abstract: In a virtualized computer system operable in more than two hierarchical privilege levels, components of a hypervisor, which include a virtual machine kernel and virtual machine monitors (VMMs), are assigned to different privilege levels. The virtual machine kernel operates at a low privilege level to be able to exploit certain features provided by the low privilege level, and the VMMs operate at a high privilege level to support execution of virtual machines. Upon determining that a context switch from the virtual machine kernel to a VMM is to be performed, the computer system exits the low privilege level, and enters the high privilege level to execute a trampoline that supports context switches to VMMs, such as state changes, and then the VMM. The trampoline is deactivated after execution control is switched to the VMM.

Abstract: In a virtualized computer system operable in more than two hierarchical privilege levels, components of a hypervisor, which include a virtual machine kernel and virtual machine monitors (VMMs), are assigned to different privilege levels. The virtual machine kernel operates at a low privilege level to be able to exploit certain features provided by the low privilege level, and the VMMs operate at a high privilege level to support execution of virtual machines. Upon determining that a context switch from the virtual machine kernel to a VMM is to be performed, the computer system exits the low privilege level, and enters the high privilege level to execute a trampoline that supports context switches to VMMs, such as state changes, and then the VMM. The trampoline is deactivated after execution control is switched to the VMM.

Abstract: Examples provide for automatically provisioning hosts in a cloud environment. A cloud daemon generates a cloud host-state configuration, for a given cloud instance of a host, stored on a cloud metadata service prior to first boot of the given cloud instance of the host. A first boot of a plurality of cloud instances of hosts is performed using a stateless, master boot image lacking host-specific configuration data. On completion of the first boot of a given cloud instance of a host, the cloud host-state configuration is installed on the master boot image to generate a self-configured boot image including host-specific configuration data for the given cloud instance of the host. A second boot is performed on the given cloud instance of the host by executing the self-configured boot image to automatically provision the given cloud instance of the host in the cloud environment.

Abstract: One embodiment of the present invention provides a system for managing storage space in a mobile device. During operation, the system detects a decrease in available disk space in a host file system, wherein an image file for a guest system is stored in the host file system. In response to the detected decrease, the system increases a size of a balloon file in a storage of a guest system. The system then receives an indication of a TRIM or discard communication and intercepts the TRIM or discard communication. Next, the system determines that at least one block is free based on the intercepted TRIM or discard communication. Subsequently, the system frees a physical block corresponding to the at least one block in a storage of the host system and reduces a size of the image file for the guest system in accordance with the intercepted TRIM or discard communication.

Abstract: A method of providing a backdoor interface between software executing in a virtual machine and a hypervisor executing on a computing system that supports the virtual machine includes trapping, at the hypervisor, an exception generated in response to execution of a debug instruction on a central processing unit (CPU) by the software; identifying, by an exception handler of the hypervisor handling the exception, an equivalence between an immediate operand of the debug instruction and a predefined value; and invoking, in response to the equivalence, a backdoor service of the hypervisor using state of at least one register of the CPU as parametric input, the state being set by the software prior to executing the debug instruction.

Abstract: In an example, a method of creating a secured workspace in a mobile device includes installing an application management agent on the mobile device, wherein the application management agent is configured to communicate with a remote server to obtain a security policy. The method further includes installing a wrapped enterprise application to the mobile device. The wrapped enterprise application includes code injected therein that, when executed by the mobile device, causes the mobile device to intercept at least a portion of instructions being executed by the wrapped enterprise application and to interpose alternative instructions that comply with the security policy. The method further includes communicating among the wrapped enterprise application, the application management agent, and other wrapped enterprise applications through pasteboard and uniform resource locator (URL) handlers provided by an operating system of the mobile device.

Abstract: In a virtualized computer system operable in more than two hierarchical privilege levels, components of a hypervisor, which include a virtual machine kernel and virtual machine monitors (VMMs), are assigned to different privilege levels. The virtual machine kernel operates at a low privilege level to be able to exploit certain features provided by the low privilege level, and the VMMs operate at a high privilege level to support execution of virtual machines. Upon determining that a context switch from the virtual machine kernel to a VMM is to be performed, the computer system exits the low privilege level, and enters the high privilege level to execute a trampoline that supports context switches to VMMs, such as state changes, and then the VMM. The trampoline is deactivated after execution control is switched to the VMM.

Abstract: A method is provided for handling interrupts in a processor, the interrupts including regular interrupts having a range of priorities and a pseudo non-maskable interrupt (PNMI) that is of a higher priority than any of the regular interrupts. The method includes obtaining an interrupt vector corresponding to a received interrupt, and if the received interrupt is a PNMI, executing a PNMI interrupt handler. If the received interrupt is a regular interrupt, the method further comprises reading a mask flag that indicates whether regular interrupts are enabled in an interrupt controller and further: if the mask flag indicates that regular interrupts are enabled, enabling interrupts in the processor so that a PNMI can be received while handling the regular interrupt, executing, a regular interrupt handler, and disabling interrupts in the processor; and if the mask flag indicates that regular interrupts are disabled, saving the interrupt vector for subsequent handling.

Abstract: A secure mode of a computer system is used to provide simulated devices. In operation, if an instruction executing in a non-secure mode accesses a simulated device, then a resulting exception is forwarded to a secure monitor executing in the secure mode. Based on the address accessed by the instruction, the secure monitor identifies the device and simulates the instruction. The secure monitor executes independently of other applications included in the computer system, and does not rely on any hardware virtualization capabilities of the computer system.

Abstract: A method is provided for handling interrupts in a processor, the interrupts including regular interrupts having a range of priorities and a pseudo non-maskable interrupt (PNMI) that is of a higher priority than any of the regular interrupts. The method includes the steps of obtaining an interrupt vector corresponding to a received interrupt, and if the received interrupt is a regular interrupt, enabling interrupts in the processor so that a PNMI can be received while handling the regular interrupt, executing a regular interrupt handler using the interrupt vector, and disabling interrupts in the processor. On the other hand, if the received interrupt is a PNMI, a PNMI interrupt handler is executed using the interrupt vector as an input thereto.

Abstract: Examples provide for automatically provisioning hosts in a cloud environment. A cloud daemon generates a cloud host-state configuration, for a given cloud instance of a host, stored on a cloud metadata service prior to first boot of the given cloud instance of the host. A first boot of a plurality of cloud instances of hosts is performed using a stateless, master boot image lacking host-specific configuration data. On completion of the first boot of a given cloud instance of a host, the cloud host-state configuration is installed on the master boot image to generate a self-configured boot image including host-specific configuration data for the given cloud instance of the host. A second boot is performed on the given cloud instance of the host by executing the self-configured boot image to automatically provision the given cloud instance of the host in the cloud environment.