Abstract: A method for managing virtual machines, the method comprising providing a virtual Advanced Configuration and Power Interface, ACPI, arranged to interact with the virtual machines, and interacting with a real ACPI based on interaction between the virtual ACPI and the plurality of virtual machines.

Abstract: According to the present invention, there is provided a data processing system comprising: a dedicated physical device for access by a single client only; a shared physical device for shared access by multiple clients; a partition of a first type associated with the dedicated physical device, the first type partition comprising said single client and a first device driver for accessing the dedicated physical device; a partition of a second type associated with the shared physical device, the second type partition comprising a second device driver for accessing the shared physical device, and a back end driver for accessing the second device driver; and multiple partitions of the third type each comprising a respective one of said multiple clients and a front end driver for accessing the shared physical device via the second type partition.

Abstract: The present invention provides a scheduling method for a data processing system comprising at least one physical CPU, and one or more virtual machines each assigned to one or more virtual CPUs, the method comprising: a first scheduling step in which one of said virtual machines is elected to run on said physical CPU; and a second scheduling step in which at least one of the virtual CPUs assigned to the elected virtual machine is elected to run on said physical CPU. The second scheduling step is applied to the virtual machine only. When a virtual machine instance is elected to run on a given CPU, the second level scheduling determines the virtual CPU instance to run. The second level scheduling is global and can cause a virtual CPU migration from one physical CPU to another. In order to ensure correct task scheduling at guest level, virtually equivalent (in terms of calculation power) virtual CPUs should be provided to the scheduler.

Abstract: The invention provides a data processing system for the support of secure networking on a single, virtualized hardware platform. The data processing system comprises a Network Interface Controller NIC to control access to a physical network; a first operating system comprising an NIC driver to manage the NIC, and a first Virtual Network Interface Controller VNIC driver. The system further comprises at least one second operating system comprising at least one second VNIC driver associated with a networking stack; and a Virtual Machine Monitor VMM to enable concurrent operation of the first and second operating systems, and to emulate a virtual network, the VMM comprising first and second VNICs to provide access to the virtual network by the first and second operating systems through the first and second VNIC drivers, respectively.

Abstract: In a preferred embodiment, the present invention provides a method of load balancing in a data processing system comprising a plurality of physical CPUs and a plurality of virtual CPUs, the method comprising: mapping one or more virtual CPUs to each of said physical CPUs; and dynamically adapting the mapping depending on the load of said physical CPUs and the negative load indicative of the load of all other virtual CPUs that are allocated to each physical CPU.

Abstract: A method of enabling multiple different operating systems to run concurrently on the same computer, comprising selecting a first operating system to have a relatively high priority (the realtime operating system. such as C5); selecting at least one secondary operating system to have a relatively lower priority (the general purpose operating system, such as Linux); providing a common program (a hardware resource dispatcher similar to a nanokernel) arranged to switch between said operating systems under predetermined conditions; and providing modifications to said first and second operating systems to allow them to be controlled by said common program.

Abstract: A method of enabling multiple different operating systems to run concurrently on the same computer, which is an Intel or similar Complex Instruction Set Computer architecture, comprising selecting a first operating system to have a relatively high priority (the realtime operating system, such as C5); selecting at least one secondary operating system to have a relatively lower priority (the general purpose operating system, such as Linux); providing a common program (a hardware resource dispatcher similar to a nanokernel) arranged to switch between said operating systems under predetermined conditions; and providing modifications to said first and second operating systems to allow them to be controlled by said common program.

Abstract: The present invention provides a scheduling method for a data processing system comprising at least one physical CPU, and one or more virtual machines each assigned to one or more virtual CPUs, the method comprising: a first scheduling step in which one of said virtual machines is elected to run on said physical CPU; and a second scheduling step in which at least one of the virtual CPUs assigned to the elected virtual machine is elected to run on said physical CPU. The second scheduling step is applied to the virtual machine only. When a virtual machine instance is elected to run on a given CPU, the second level scheduling determines the virtual CPU instance to run. The second level scheduling is global and can cause a virtual CPU migration from one physical CPU to another. In order to ensure correct task scheduling at guest level, virtually equivalent (in terms of calculation power) virtual CPUs should be provided to the scheduler.

Abstract: A method for managing virtual machines, the method comprising providing a virtual Advanced Configuration and Power Interface, ACPI, arranged to interact with the virtual machines, and interacting with a real ACPI based on interaction between the virtual ACPI and the plurality of virtual machines. (FIG.

Abstract: The invention provides a data processing system for the support of secure networking on a single, virtualized hardware platform. The data processing system comprises a Network Interface Controller NIC to control access to a physical network; a first operating system comprising an NIC driver to manage the NIC, and a first Virtual Network Interface Controller VNIC driver. The system further comprises at least one second operating system comprising at least one second VNIC driver associated with a networking stack; and a Virtual Machine Monitor VMM to enable concurrent operation of the first and second operating systems, and to emulate a virtual network, the VMM comprising first and second VNICs to provide access to the virtual network by the first and second operating systems through the first and second VNIC drivers, respectively.

Abstract: According to the present invention, there is provided a data processing system comprising: a dedicated physical device for access by a single client only; a shared physical device for shared access by multiple clients; a partition of a first type associated with the dedicated physical device, the first type partition comprising said single client and a first device driver for accessing the dedicated physical device; a partition of a second type associated with the shared physical device, the second type partition comprising a second device driver for accessing the shared physical device, and a back end driver for accessing the second device driver; and multiple partitions of the third type each comprising a respective one of said multiple clients and a front end driver for accessing the shared physical device via the second type partition.

Abstract: In a preferred embodiment, the present invention provides a method of load balancing in a data processing system comprising a plurality of physical CPUs and a plurality of virtual CPUs, the method comprising: mapping one or more virtual CPUs to each of said physical OPUs; and dynamically adapting the mapping depending on the load of said physical CPUs.

Abstract: Multiple different operating systems are enabled to run concurrently on the same computer. A first operating system is selected to have a relatively high priority (the realtime operating system, such as C5). At least one secondary operating system is selected to have a relatively lower priority (the general purpose operating system, such as Linux). A common program (a hardware resource dispatcher similar to a nanokernel) is arranged to switch between these operating systems under predetermined conditions and modifications are provided to the first and second operating systems to allow them to be controlled by the common program.

Abstract: A method of enabling multiple different operating systems to run concurrently on the same computer, which is an Intel or similar Complex Instruction Set Computer architecture, comprising selecting a first operating system to have a relatively high priority (the realtime operating system, such as C5); selecting at least one secondary operating system to have a relatively lower priority (the general purpose operating system, such as Linux); providing a common program (a hardware resource dispatcher similar to a nanokernel) arranged to switch between said operating systems under predetermined conditions; and providing modifications to said first and second operating systems to allow them to be controlled by said common program.

Abstract: A computer system configured for communications, comprising: a processor; a first operating system running on the processor; a second operating system running on the processor; and a network interface for communicating packet data, characterised in that the first and second operating systems are arranged to share access to the network interface.

Abstract: A method of enabling multiple different operating systems to run concurrently on the same computer, comprising selecting a first operating system to have a relatively high priority (the realtime operating system. such as C5); selecting at least one secondary operating system to have a relatively lower priority (the general purpose operating system, such as Linux); providing a common program (a hardware resource dispatcher similar to a nanokernel) arranged to switch between said operating systems under predetermined conditions; and providing modifications to said first and second operating systems to allow them to be controlled by said common program.

Abstract: A computer system comprises first and second computer boards, each having a processor, onboard memory, an onboard bus, e.g. a processor bus, and a bus-to-bus bridge for interconnecting the onboard bus with an external bus; the boards have remote slave drivers, and communication drivers, comprising communication management functions, and forming communication chains or channels between the remote slave drivers and the onboard memories.

Abstract: Each driver has a global driver section comprising drive program code and global driver data, both defining driver operations associated with a corresponding class of devices. Each device has an associated driver instantiation comprising local driver data, having an internal pointer to the global driver section of the instantiated driver, and possibly at least one external pointer to another driver instantiation. A device registry forms a list of device registry entries, each corresponding to a respective one of the drive instantiations. Driveer client code may perform operations on a given device by fetching in the device registry a pointer to the driver instantiation associated with the given device, and then use operations provided by the associated driver instantiation, directly or using further operations reached in other driver instantiations by using iteratively the external printer.

Abstract: A method of enabling multiple different operating systems to run concurrently on the same computer, comprising selecting a first operating system to have a relatively high priority (the realtime operating system, such as C5); selecting at least one secondary operating system to have a relatively lower priority (the general purpose operating system, such as Linux); providing a common program (a hardware resource dispatcher similar to a nanokernel) arranged to switch between said operating systems under predetermined conditions; and providing modifications to said first and second operating systems to allow them to be controlled by said common program.

Abstract: Each driver has a global driver section comprising drive program code and global driver data, both defining driver operations associated with a corresponding class of devices. Each device has an associated driver instantiation comprising local driver data, having an internal pointer to the global driver section of the instantiated driver, and possibly at least one external pointer to another driver instantiation. A device registry forms a list of device registry entries, each corresponding to a respective one of the drive instantiations. Driveer client code may perform operations on a given device by fetching in the device registry a pointer to the driver instantiation associated with the given device, and then use operations provided by the associated driver instantiation, directly or using further operations reached in other driver instantiations by using iteratively the external printer.