Enhanced network system through the combination of network objects

Reducing the cost of framing network packets in a virtual machine environment combines certain network objects to eliminate the cost of fully framing packets between the combined objects. In a virtual environment, for example, this allows a virtual NIC in one partition to send only data to a network provider partition and to rely on the latter to frame and route the data. A source network object, destination network object, or an intermediate network object may enable a separate intermediate network object to frame its data so that the network system may take advantage of offload framing when one or more of the intermediate network object's ports has the capacity to offload framing.

FIELD OF THE INVENTION

The invention is directed to systems and methods for routing network data in a network including virtual machines (VMs) and, more particularly, the invention is directed to systems and methods of combining network objects in the network to minimize packet framing overhead and to, where possible, offload the framing of a packet to hardware.

BACKGROUND OF THE INVENTION

In a traditional network environment, there are end stations and intermediate stations. Each end station can be thought of as a Network Interface Card (NIC) or network adapter. An end station may be either the originator of a network packet or the final destination of a network packet. The intermediate stations, on the other hand, can be thought of as switches, hubs, routers, repeaters, or the like that are disposed between the end stations to aid them in the delivery of their network packets.

Raw data cannot be sent between two end stations in a network environment since the raw data does not include the information required to get it to the destination. Framing is used to provide such information and to divide the raw data into data packets for the network transmission. As used herein, framing refers to the addition of meta data around the raw data that provides the intermediate stations with information on how to send the packets and provides the destination end station with information on what each packet contains. Framing can be performed many times on a packet and normally occurs once for each OSI level the packet must traverse. Examples of typical framing include TCP/UDP, IP, and Ethernet. As known to those skilled in the art, the framing also might include consistency checks to guarantee the integrity of the packet.

Thus, in traditional network environments, end stations create, send, and receive packets while the intermediate stations either route or forward the packets between end stations or other intermediate stations. In this environment, all stations receive and send fully framed network packets consisting of, at a minimum, routing information and data.

The problem with the traditional network environment is that the framing of network packets has become increasing costly in CPU processing time as the network throughput has gone up. This has been addressed, in part, by providing end stations with the hardware capacity to frame a packet without the CPU cost by offloading the packet framing to hardware. For example, a TCP/IP offload engine (TOE) is a new hardware standard that allows a NIC to perform the framing of a TCP/IP packet in hardware. This technology greatly decreases the amount of CPU processing time required to send and receive network packets. As an example, Virtual PC 2004 and Virtual Server 2005 by Microsoft Corporation frame the network packet before it is sent to the host. Unfortunately, even if the host has a network card capable of framing the packet in hardware, such as TOE, it is not used for the guest's traffic, which continues to be framed in software, costing CPU processing time.

A typical network has a tree topology. The leaves of the tree are the end stations and the branches and the root are the intermediate stations. In a smart (switched) network, the packet flows up the tree through the intermediate stations only as far as necessary to get to the intermediate station that has a lower connection to the destination end station. For example,FIG. 1illustrates a network topology in which end stations D and E are connected to intermediate station B and end stations F and G are connected to intermediate station C. Intermediate stations B and C are connected to intermediate station A. Thus, to send a packet from end station D to end station G, the packet will travel through intermediate stations A, B, and C. In order to propagate information through the system ofFIG. 1, an external protocol must be used to frame the network packets such that all connected network stations can understand the packet. In the example ofFIG. 1, the network packets would need to be understood by intermediate stations A, B, and C and sufficient meta data would need to be wrapped around the raw data in the network packets for this purpose. This leads to significant overhead, particularly as the number of intermediate stations increases.

The maximum transmission unit (MTU) specifies the maximum amount of data that can be sent in a single packet (after framing). Typically, Ethernet supports an MTU of 1500 bytes; however, recent Ethernet standards such as gigabit Ethernet have increased the MTU to 9000 bytes. These larger packets are referred to as jumbo frames. The MTU of a local area network (LAN) is generally computed by sending packets of different sizes and seeing which ones timeout or return an error. The MTU of the LAN will then be the largest packet that do not return an error. A LAN with a large MTU will generally have higher performance because large packets will not have to be fragmented. A LAN with a small MTU, on the other hand, will generally require less configuration because it more likely that all of the intermediate stations on the LAN will be able to support the smaller MTU.

Traditional networks are limited by the aggregate bandwidth lost due to the network's tree structure. In other words, while the tree topology is cost effective in terms of hardware and configurability, it is wasteful in terms of bandwidth since the aggregate bandwidth is wasted when packets must travel between intermediate stations with relatively small MTUs. In the above example, when end station D inFIG. 1must send a packet to end station G, the LAN bandwidth of intermediate stations A, B, and C must be consumed, thereby limiting the aggregate bandwidth.

A solution to these problems is desired that minimizes the amount of framing and offloads the framing to hardware where possible. A solution is also desired that maximizes the network MTU. The invention provides such solutions.

SUMMARY OF THE INVENTION

The invention provides solutions to the network problems mentioned above by combining end stations and intermediate stations and combining intermediate stations with each other. In an exemplary implementation, the invention is used in a virtual machine system since the network entities and their connections are all known, or knowable, to the host system(s) and may be shared to maximize network communication in accordance with the techniques of the invention. In such an enhanced system, end station entities will sometimes send fully framed packets to the intermediate stations or they may send only the data to the intermediate stations and rely on the intermediate station to properly frame the data or offload the framing after the proper route has been determined. The same can be said for the data transfer between two intermediate stations. Once the stations have been combined, the end station in the system can query information, such as the maximum transmission unit (MTU) of the network, from the intermediate station or the intermediate stations can determine optimizations in the network and cause the topology of the network to change.

In exemplary embodiments, a virtual machine system is provided comprising a source network object, an intermediate network object, and a destination network object, as well as a network channel and a control channel. In accordance with the invention, the network channel connects the source network object, the intermediate network object, and/or the destination network object and is configured to send framed data packets between respective network objects. The control channel, on the other hand, is separate from the network channel and connects at least two of the source network object, the intermediate network object, and the destination network object and configured to send control data messages between the connected network objects. In exemplary embodiments, the control channel may comprise a software connection between respective network objects, a packet bus connection between respective network objects, or a sub-protocol of a standard protocol stack for the framed data packets.

In accordance with the invention, the control data messages include routing/topology data for reconfiguring the respective network objects to change a routing of the framed data packets between at least the intermediate network object and the destination network object. The control data messages may also enable respective network objects to setup a path for the sending of not fully framed data packets, or data packets that are inappropriate for transmission, between the respective network objects. Such control data messages may include TCP/IP checksums or a request that a TCP/IP offload engine (TOE) connection be established. In the case of a TOE connection request, the network object receiving the TOE connection request looks up a port corresponding to the network address of the TOE connection request in a routing table to determine that the particular network address is available via an adjacent network object and establishes a communication link between the network object that sent the TOE connection request and the determined adjacent network object by forwarding the received TOE connection request to the adjacent network object. On the other hand, if the network object receiving the TOE connection request determines that the TOE connection request should not be forwarded, the network object handles the TOE connection request locally.

In accordance with a further exemplary embodiment, the control data messages may enable a network object besides the source network object to break apart a partially or fully framed data packet using a large send offload. The control data messages may also enable a network object besides the source network object to frame the data packets with meta data including routing information for each data packet and information on what each data packet contains for transmission to another network object via the network channel. In the latter case, the network object besides the source network object may offload a received message to framing hardware that frames the message into TCP/IP packets.

In another exemplary embodiment of the invention, the control data messages include at least one network property of a network object, such as a maximum transmission unit (MTU) size for a communication path between respective network objects. The source network object may query the intermediate network object for a transmission property of the intermediate network object, or the intermediate network object may push a transmission property of the intermediate network object, such as the MTU, to the source network object. The transmission property data may then be used by the source network object to improve transmission efficiency.

In still another exemplary embodiment of the invention, the techniques of the invention may be used for network reconfiguration. In this embodiment, the intermediate network object provides routing data to the source network object, where the routing data identifies a next intermediate network object and/or the destination network object in a network topology of the virtual machine system. The source network object uses the routing data to create a communications path directly to the destination network object or the next intermediate network object so as to exclude the intermediate network object from the communications path. The next intermediate network object may also provide further routing data to the source network object, where the further routing data identifies an additional intermediate network object and/or the destination network object in the network topology of the virtual machine system. As before, the source network object may use the further routing data to create a communications path directly to the destination network object or the additional intermediate network object so as to exclude the intermediate network object and the next intermediate network object from the communications path. The source network object may also determine that the intermediate network object and an additional network object should be combined and then send a message to both the intermediate network object and the additional intermediate network object instructing them to create a connection to a particular network address so that subsequent messages between them may pass through each such connection.

The scope of the invention also includes corresponding methods of communicating data between respective network objects in a virtualized computer system as well as computer readable media including software that performs the methods of the invention when read by a suitable host computer system. Additional characteristics of the invention will be apparent to those skilled in the art based on the following detailed description.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Overview

The invention provides systems and methods for determining network optimizations in a VM network and combining network objects to provide such optimizations. Generally, a source network object knows the identity of the destination network object but it has no idea of how data is routed to it. By combining the source network object with an intermediate network object, the source network object may learn much more information about the network and use this information to take advantage of features in the intermediate station.

For example, the source network object, the destination network object, or an intermediate network object may enable a separate intermediate network object to frame its data. This feature enables the system to take advantage of offload framing when one or more of the intermediate network object's ports has the capacity to offload framing, including, for example, TCP/IP checksums, large sends, IP security, and TCP/IP offload engines.

In an embodiment of the invention, an intermediate network object performs the offload itself. Even when such an offload is for network objects using the same CPU, it saves CPU processing since these technologies will reduce context switches between the end stations (source and destination network objects) and the intermediate network objects.

In another embodiment of the invention, the source or destination network object may query the intermediate network object for properties or the intermediate network object may push its properties to the source and/or destination network objects through a back control data communications channel that is separate from the data packet communications channel. For example, the maximum transmission unit (MTU) of the local area network (LAN) may be queried by or pushed to the source or destination network object using the control channel.

In yet another embodiment of the invention, an intermediate network object may reconfigure the VM network for the purpose of efficiency by reconfiguring the network tree into a graph for increased performance for traffic moving between the nodes.

Other more detailed aspects of the invention are described below, but first, the following description provides a general overview of and some common vocabulary for virtual machines and associated terminology as the terms have come to be known in connection with operating systems and the host processor (“CPU”) virtualization techniques. In doing so, a set of vocabulary is set forth that one of ordinary skill in the art may find useful for the description that follows of the apparatus, systems and methods for determining network optimizations in a VM network and combining network objects to provide such optimizations in accordance with the invention.

Overview of Virtual Machines

Computers include general purpose central processing units (CPUs) or “processors” that are designed to execute a specific set of system instructions. A group of processors that have similar architecture or design specifications may be considered to be members of the same processor family. Examples of current processor families include the Motorola 680X0 processor family, manufactured by International Business Machines (IBM) or Motorola, Inc. of Phoenix, Ariz.; the Intel 80X86 processor family, manufactured by Intel Corporation of Sunnyvale, Calif.; and the PowerPC processor family, which is manufactured by IBM, Inc. and Motorola, Inc. and used in computers manufactured by Apple Computer, Inc. of Cupertino, Calif. Although a group of processors may be in the same family because of their similar architecture and design considerations, processors may vary widely within a family according to their clock speed and other performance parameters.

Each family of microprocessors executes instructions that are unique to the processor family. The collective set of instructions that a processor or family of processors can execute is known as the processor's instruction set. As an example, the instruction set used by the Intel 80X86 processor family is incompatible with the instruction set used by the PowerPC processor family. The Intel 80X86 instruction set is based on the Complex Instruction Set Computer (CISC) format, while the Motorola PowerPC instruction set is based on the Reduced Instruction Set Computer (RISC) format. CISC processors use a large number of instructions, some of which can perform rather complicated functions, but which generally require many clock cycles to execute. RISC processors, on the other hand, use a smaller number of available instructions to perform a simpler set of functions that are executed at a much higher rate.

The uniqueness of the processor family among computer systems also typically results in incompatibility among the other elements of hardware architecture of the computer systems. A computer system manufactured with a processor from the Intel 80X86 processor family will have a hardware architecture that is different from the hardware architecture of a computer system manufactured with a processor from the PowerPC processor family. Because of the uniqueness of the processor instruction set and a computer system's hardware architecture, application software programs are typically written to run on a particular computer system running a particular operating system.

Generally speaking, computer manufacturers try to maximize their market share by having more rather than fewer applications run on the microprocessor family associated with the computer manufacturers' product line. To expand the number of operating systems and application programs that can run on a computer system, a field of technology has developed in which a given computer having one type of CPU, called a host, will include a virtualizer program that allows the host computer to emulate the instructions of an unrelated type of CPU, called a guest. Thus, the host computer will execute an application that will cause one or more host instructions to be called in response to a given guest instruction, and in this way the host computer can both run software designed for its own hardware architecture and software written for computers having an unrelated hardware architecture.

As a more specific example, a computer system manufactured by Apple Computer, for example, may run operating systems and programs written for PC-based computer systems. It may also be possible to use virtualizer programs to execute concurrently on a single CPU multiple incompatible operating systems. In this latter arrangement, although each operating system is incompatible with the other, virtualizer programs can host each of the several operating systems and thereby allowing the otherwise incompatible operating systems to run concurrently on the same host computer system.

When a guest computer system is emulated on a host computer system, the guest computer system is said to be a “virtual machine” as the guest computer system only exists in the host computer system as a pure software representation of the operation of one specific hardware architecture. Thus, an operating system running inside virtual machine software such as Microsoft's Virtual PC may be referred to as a “guest” and/or a “virtual machine,” while the operating system running the virtual machine software may be referred to as the “host.” The terms virtualizer, emulator, direct-executor, virtual machine, and processor emulation are sometimes used interchangeably to denote the ability to mimic or emulate the hardware architecture of an entire computer system using one or several approaches known and appreciated by those of skill in the art. Moreover, all uses of the term “emulation” in any form is intended to convey this broad meaning and is not intended to distinguish between instruction execution concepts of emulation versus direct-execution of operating system instructions in the virtual machine. Thus, for example, Virtual PC software available from Microsoft Corporation “emulates” (by instruction execution emulation and/or direct execution) an entire computer that includes an Intel 80X86 Pentium processor and various motherboard components and cards, and the operation of these components is “emulated” in the virtual machine that is being run on the host machine. A virtualizer program executing on the operating system software and hardware architecture of the host computer, such as a computer system having a PowerPC processor, mimics the operation of the entire guest computer system.

The general case of virtualization allows one processor architecture to run OSes and programs from other processor architectures (e.g., PowerPC Mac programs on x86 Windows, and vice versa), but an important special case is when the underlying processor architectures are the same (run various versions of x86 Linux or different versions of x86 Windows on x86). In this latter case, there is the potential to execute the Guest OS and its applications more efficiently since the underlying instruction set is the same. In such a case, the guest instructions are allowed to execute directly on the processor without losing control or leaving the system open to attack (i.e., the Guest OS is sandboxed). This is where the separation of privileged versus non-privileged and the techniques for controlling access to memory comes into play. For virtualization where there is an architectural mismatch (PowerPC <−> x86), two approaches could be used: instruction-by-instruction emulation (relatively slow) or translation from the guest instruction set to the native instruction set (more efficient, but uses the translation step). If instruction emulation is used, then it is relatively easy to make the environment robust; however, if translation is used, then it maps back to the special case where the processor architectures are the same.

In accordance with the invention, the guest operating systems are virtualized and thus an exemplary scenario in accordance with the invention would be emulation of a Windows95®, Windows98®, Windows 3.1, or Windows NT 4.0 operating system on a Virtual Server available from Microsoft Corporation. In various embodiments, the invention thus describes systems and methods for controlling guest access to some or all of the underlying physical resources (memory, devices, etc.) of the host computer.

The virtualizer program acts as the interchange between the hardware architecture of the host machine and the instructions transmitted by the software (e.g., operating systems, applications, etc.) running within the emulated environment. This virtualizer program may be a host operating system (HOS), which is an operating system running directly on the physical computer hardware (and which may comprise a hypervisor). Alternately, the emulated environment might also be a virtual machine monitor (VMM) which is a software layer that runs directly above the hardware, perhaps running side-by-side and working in conjunction with the host operating system, and which can virtualize all the resources of the host machine (as well as certain virtual resources) by exposing interfaces that are the same as the hardware the VMM is virtualizing. This virtualization enables the virtualizer (as well as the host computer system itself) to go unnoticed by operating system layers running above it.

Processor emulation thus enables a guest operating system to execute on a virtual machine created by a virtualizer running on a host computer system comprising both physical hardware and a host operating system.

From a conceptual perspective, computer systems generally comprise one or more layers of software running on a foundational layer of hardware. This layering is done for reasons of abstraction. By defining the interface for a given layer of software, that layer can be implemented differently by other layers above it. In a well-designed computer system, each layer only knows about (and only relies upon) the immediate layer beneath it. This allows a layer or a “stack” (multiple adjoining layers) to be replaced without negatively impacting the layers above the layer or stack. For example, software applications (upper layers) typically rely on lower levels of the operating system (lower layers) to write files to some form of permanent storage, and these applications do not need to understand the difference between writing data to a floppy disk, a hard drive, or a network folder. If this lower layer is replaced with new operating system components for writing files, the operation of the upper layer software applications remains unaffected.

The flexibility of layered software allows a virtual machine (VM) to present a virtual hardware layer that is in fact another software layer. In this way, a VM can create the illusion for the software layers above it that the software layers are running on their own private computer system, and thus VMs can allow multiple “guest systems” to run concurrently on a single “host system.” This level of abstraction is represented by the illustration ofFIG. 2A.

FIG. 2Ais a diagram representing the logical layering of the hardware and software architecture for an emulated operating environment in a computer system. In the figure, an emulation program54runs directly or indirectly on the physical hardware architecture52. Emulation program54may be (a) a virtual machine monitor that runs alongside a host operating system, (b) a specialized host operating system having native emulation capabilities, or (c) a host operating system with a hypervisor component wherein the hypervisor component performs the emulation. Emulation program54emulates a guest hardware architecture56(shown as broken lines to illustrate the fact that this component is the “virtual machine,” that is, hardware that does not actually exist but is instead emulated by the emulation program54). A guest operating system58executes on the guest hardware architecture56, and software application60runs on the guest operating system58. In the emulated operating environment of FIG.2A—and because of the operation of emulation program54—software application60may run in computer system50even if software application60is designed to run on an operating system that is generally incompatible with the host operating system and hardware architecture52.

FIG. 2Billustrates a virtualized computing system comprising a host operating system software layer64running directly above physical computer hardware62where the host operating system (host OS)64provides access to the resources of the physical computer hardware62by exposing interfaces that are the same as the hardware the host OS is emulating (or “virtualizing”)—which, in turn, enables the host OS64to go unnoticed by operating system layers running above it. Again, to perform the emulation the host OS64may be a specially designed operating system with native emulations capabilities or, alternately, it may be a standard operating system with an incorporated hypervisor component for performing the emulation (not shown).

As shown inFIG. 2B, above the host OS64are two virtual machine (VM) implementations, VM A66, which may be, for example, a virtualized Intel 386 processor, and VM B68, which may be, for example, a virtualized version of one of the Motorola 680X0 family of processors. Above each VM66and68are guest operating systems (guest OSes) A70and B72respectively. Running above guest OS A70are two applications, application A174and application A276, and running above guest OS B72is application B178.

In regard toFIG. 2B, it is important to note that VM A66and VM B68(which are shown in broken lines) are virtualized computer hardware representations that exist only as software constructions and which are made possible due to the execution of specialized emulation software(s) that not only presents VM A66and VM B68to Guest OS A70and Guest OS B72respectively, but which also performs all of the software steps necessary for Guest OS A70and Guest OS B72to indirectly interact with the real physical computer hardware62.

FIG. 2Cillustrates an alternative virtualized computing system wherein the emulation is performed by a virtual machine monitor (VMM)64′ running alongside the host operating system64″. For certain embodiments the VMM64′ may be an application running above the host operating system64″ and interacting with the physical computer hardware62only through the host operating system64″. In other embodiments, and as shown inFIG. 2C, the VMM64′ may instead comprise a partially independent software system that on some levels interacts indirectly with the computer hardware62via the host operating system64″ but on other levels the VMM64′ interacts directly with the computer hardware62(similar to the way the host operating system interacts directly with the computer hardware). And in yet other embodiments, the VMM64′ may comprise a fully independent software system that on all levels interacts directly with the computer hardware62(similar to the way the host operating system64″ interacts directly with the computer hardware62) without utilizing the host operating system64″ (although still interacting with the host operating system64″ insofar as coordinating use of the computer hardware62and avoiding conflicts and the like).

All of these variations for implementing the virtual machine are anticipated to form alternative embodiments of the invention as described herein, and nothing herein should be interpreted as limiting the invention to any particular emulation embodiment. In addition, any reference to interaction between applications74,76, and78via VM A66and/or VM B68respectively (presumably in a hardware emulation scenario) should be interpreted to be in fact an interaction between the applications74,76, and78and the virtualizer that has created the virtualization. Likewise, any reference to interaction between applications VM A66and/or VM B68with the host operating system64and/or the computer hardware62(presumably to execute computer instructions directly or indirectly on the computer hardware62) should be interpreted to be in fact an interaction between the virtualizer that has created the virtualization and the host operating system64and/or the computer hardware62as appropriate.

Combining Network Objects in a VM System

The invention provides solutions to the problems presented above by creating an enhanced network system in which one or more source or destination network objects (end stations) are combined with one or more intermediate network objects.FIG. 3illustrates the enhanced network system80of the invention whereby VM software partitions1(82) and2(84) contain the source and destination network objects (end stations)86,88, respectively, while the network provider software partition90contains the intermediate network object (intermediate station)92that is to be combined with the source and/or destination network objects86,88. InFIG. 3, there are only two end station partitions whereby the communication path will be constrained only by system resources.

Generally speaking, the enhanced network system ofFIG. 3does not have to be different from a traditional network system. In theFIG. 3embodiment, the virtual network interface cards (NICs)86and88inside of VM software partitions1(82) and2(84) may be NDIS miniport drivers that fully frame an Ethernet packet and send the packet to the network provider partition90through a software bus94. A switch92inside of the network provider partition90may use the destination MAC address in the Ethernet packet to route the packet to the appropriate destination. In an exemplary embodiment, switch92is an OSI layer2multiport bridge implemented as an NDIS intermediate driver that satisfies the IEEE 802.3d switch specification for the implementation of VLANs, priority queuing, or any other standard switch functionality. As illustrated, the network provider partition90may further include a physical NIC1(96) that has hardware offload capacity (e.g., TOE) enabled and a physical NIC2(98) that does not have any hardware offload capacity. The hardware offload capacity may also be implemented as a large send offload whereby the physical NIC breaks a single large TCP/IP packet (that may otherwise be too large or inappropriate to transmit) into multiple segments according to the MTU of the network. Each of these physical NICS96,98provides data to/from network provider partition90and partitions1(82) and2(84) and a data network such LAN/Internet100. In accordance with the invention, while working in this mode the packet framing taking place inside of the end stations86and88based on the appropriate network protocols (e.g., TCP/IP) are not able to take advantage of the hardware offload capacity in physical NIC1(96) even if the data is destined to go through that connection to the data network100. As illustrated, the enhanced network system80is plugged into the respective partitions via standard NDIS interfaces102.

FIG. 4illustrates how the enhanced network system80of the invention sends control data and Ethernet packets amongst the partitions via a software pipe. InFIG. 4, the rectangles illustrate data packets being sent between the end station82and the intermediate station90. As shown, the end station82sends control data104that is followed by an Ethernet frame106encapsulated with control data104as illustrated. The intermediate station90relays the Ethernet frame106to an end station82as illustrated. As will be appreciated by those skilled in the art, in this example the control data is essentially at OSI layer1.5.

Alternatively, as shown inFIG. 5A, the control message may be transmitted between the end station82and intermediate station90via a dedicated software pipe (back channel)108while the Ethernet frames are transmitted via a separate dedicated software pipe110. In a normal network environment, the connections between adjacent network objects are made by a single standard channel, such as software pipe110, through which fully framed packets are sent through the network. On the other hand, software pipe108in accordance with the invention serves as an out-of-band control channel between the network objects and is independent of the standard full packet channel (software pipe110). Software pipe108provides direct communications between adjacent network objects and sends control data to adjacent network objects.

In the embodiment ofFIG. 5A, the back channel108is used to send control data to adjacent network objects in one of two ways. First, if the channels between the network objects are easily creatable, then the back channel108can be created in a similar fashion to the conventional software pipe110and the two channels can become a single network connection. This scenario is readily available in a virtual machine environment where the second channel is a software connection as illustrated inFIG. 5B. This configuration is also possible in a physical environment at a much higher cost. A possible scenario might include putting a packet bus such as a USB port on a NIC and switch and using the packet bus connection as the control channel as shown inFIG. 5C. Those skilled in the art will appreciate that other packet bus connections such as firewire and Bluetooth may also be used. The second way a control channel can be established is by sub-layering the control channel108in the standard channel110. As illustrated inFIG. 5D, if a new layer is created below the lowest defined layer of the standard defined stacking layer for the packets being sent, then the network object can send control data without perturbing the standard packets. As a result, the connection between the two network objects using the second method may have a single dual-purpose channel as shown inFIG. 5E.

The enhanced network system80of the invention enables the virtual NICs86,88of the partitions to send unframed data to the switch92. This is accomplished in accordance with the invention by the virtual NIC86or88sending control information104to the switch92using the techniques ofFIG. 4or5requesting a data path to the destination network object. In accordance with standard intelligent switching techniques, the switch92will determine where the path should be created (either to a physical NIC such as physical NIC96, a network protocol, or to another virtual NIC) and sets up the mechanisms for controlling the reception of data on the path so that the end stations need not do so. In the case where the path is created to the physical NIC1(96), for example, the unframed data will then be framed by the physical NIC1(96) in hardware using hardware assist techniques such as TOE, thus significantly reducing the amount of CPU processing required to send the packet. On the other hand, in the case where the packet was destined for the physical NIC2(98), the network protocol, or another partition's end station, then the data path will be only to the switch92since none of these connections support the framing in hardware. Data sent by the source partition (source network object) will then be framed and routed by the switch92thereby fooling the source partition into thinking that the framing was done in hardware. Although framing the packet by the switch92will require the same amount of CPU processing time as the virtual NIC framing implementation, there still will be savings in the communication required between the two components since the virtual NIC86,88can send the data in a single large section instead of individually framed segments, resulting in a net packet reduction.

FIG. 6illustrates a TCP/IP offload engine connection being established between virtual NIC A86in partition1(82) and the physical NIC1(96) of the network provider partition90. In this example, the virtual NIC A86sends a control packet104to the switch92requesting a TOE connection be established to MAC address C (step1). The switch92looks up the port corresponding to MAC address C in its routing tables and learns that physical NIC1(96) is the target destination network object (step2). The switch92then forwards the TOE request to the physical NIC1(96) and the physical NIC1(96) accepts the connection. A path112is then created for data to flow from virtual NIC A86to the hardware offload (TOE) in physical NIC1(96) (step4). Once the path112is created, all associated data sent or received through the TOE connection will use the path112(step5), thereby allowing virtual NIC A86to directly take advantage of the hardware96owned by the network provider partition90. As illustrated at the bottom ofFIG. 6, a TOE request contains all the data for appending the Ethernet, IP and TCP headers to the application's data. Since the TOE offload has the information necessary to add the headers, those skilled in the art will appreciate that step5involves only sending the data across the path created in step4.

FIG. 7illustrates a TCP/IP offload engine connection being established between a virtual NIC A86in partition1(82) and the switch92in the network provider partition90. In this example, the virtual NIC A86sends a control packet104to the switch92requesting a TOE connection be established to MAC address C (step1). The switch92looks up the port corresponding to MAC address C in its routing tables and learns that physical NIC1(96) is the target destination network object (step2). However, in this example, the hardware offload capacity of physical NIC1(96) is disabled. Since the switch92knows that physical NIC1(96) cannot support a TOE connection, the switch92sets up the proper structures to handle the TOE data sends itself (step3). A path114is then created for data to flow from virtual NIC A86to the virtual offload in switch92(step4). Once the path114is created, all associated data sent or received through the TOE connection will use the path114(step5), thereby allowing virtual NIC A86to think that offload hardware exists when it does not. Although the CPU will still be tasked with prepending the headers to the application's data in this embodiment, the overall performance will still be increased since the number of messages being sent to virtual NIC A86will be decreased through TCP acknowledgment (ACK) coalescing and TCP segmentation in the switch92. As in theFIG. 6embodiment, a TOE request contains all the data for appending the Ethernet, IP and TCP headers to the application's data. Since the TOE offload has the information necessary to add the headers, those skilled in the art will appreciate that step5involves only sending the data across the path created in step4.

The enhanced network system80of the invention also permits the VM system to reconfigure the network topology on the fly when it can increase overall system performance. An example of network topology reconfiguration on the fly will be explained with respect to the topology change over a single intermediate station (FIG. 8) and a topology progression of a reconfiguration of the network topology ofFIG. 1over multiple intermediate stations (FIG. 9) utilizing the techniques of the invention.

FIG. 8illustrates a topology change on the fly where there is only a single intermediate station (network provider partition90) between end stations (partitions1(82) and partition2(84)). In this example, the switch92of the network provider partition90sends a control message to the virtual NIC A86telling it that the machine with MAC B is located at partition2(84) (step1). Virtual NIC A86then offers a software pipe to the virtual NIC B88of partition2(84) (step2). Upon acceptance of the software pipe, virtual NIC A86sends all subsequent packets addressed to MAC B through the software pipe to virtual NIC B88(step3). Likewise, virtual NIC B88sends all subsequent packets addressed to MAC A through the software pipe it accepted in step2.

As illustrated inFIG. 9Afor an example of a topology progression of a reconfiguration of the network topology ofFIG. 1for multiple intermediate stations, end station (source network object) D sends numerous packets to end station G via intermediate stations (network objects) A, B and C. A switch in, for example, intermediate station A recognizes that a virtual NIC of intermediate station B and a virtual NIC of intermediate station C need to be connected for some reason. This could be caused by recognition by intermediate station A of heavy traffic between the virtual NICs of intermediate stations B and C or some user configurable setting. Intermediate station A sends control signals104as inFIG. 4or5to intermediate stations B and C instructing these stations to change the topology. For example, the switch of intermediate station A may send a message to both virtual NICs of intermediate stations B and C telling them of the address and the partition ID to which they should create a connection. The address allows them to route their own packets to their newly created connections. One virtual NIC offers a connection to the other virtual NIC, and a connection116between intermediate stations B and C is established as illustrated inFIG. 9B. Then, packets destined for the virtual NIC of the other intermediate station are now sent through the new connection and intermediate station A is bypassed.

Then, starting with the configuration inFIG. 9B, a switch in intermediate station B may recognize that a virtual NIC or physical NIC of end station D is sending heavy traffic to intermediate station C. Intermediate station B sends control signals104as inFIG. 4or5to end station D and intermediate station C instructing these stations to change the topology. As above, the switch of intermediate station B may send a message to both the NICs of end station D and intermediate station C telling them of the address and the partition ID to which they should create a connection. The address allows them to route their own packets to their newly created connections. One NIC offers a connection to the other NIC, and a connection118between end station D and intermediate station C is established as illustrated inFIG. 9C. Then, packets destined for the NIC of the other station are now sent through the new connection118and intermediate station B and connection116are bypassed.

Next, starting with the configuration inFIG. 9C, a switch in intermediate station C may recognize that a virtual NIC or physical NIC of end station D is sending heavy traffic to end station G. Intermediate station C thus sends control signals104as inFIG. 4or5to end stations D and G instructing these stations to change the topology. As above, the switch of intermediate station C may send a message to both the NICs of end stations D and G telling them of the address and the partition ID to which they should create a connection. The address allows them to route their own packets to their newly created connections. One NIC offers a connection to the other NIC, and a direct connection (D-G pipe)120between end stations D and G is established as illustrated inFIG. 9D. Then, packets destined for the NIC of the other end station are now sent through the D-G pipe120and intermediate station C and connection118are bypassed.

Thus, so long as end station G's MAC address is known, the destination software pipe D-G120may be used to optimally send data between source end station D and destination end station G. However, if the address of end station G is not known, then a default pipe will be used. As known to those skilled in the art, the default pipe is the first established network connection where full frames are sent and destinations are learned by the intermediate station snooping and recording information from the passing packets.

In accordance with another embodiment of the invention, the enhanced network system80enables the virtual NICs86,88and the switch92to exchange network information such as the maximum transmission unit (MTU) of the network100to which the virtual NICs86,88are connected. For example, in the embodiment ofFIG. 10, the network information, such as the MTU, may be changed by the network provider partition90. In this embodiment, the switch92determines that a property or event has changed inside the network (e.g., the MTU), and the switch92pushes the new property or event through a control message104(FIGS. 4,5) to the virtual NICs86,88of the end stations82,84. The adjustment in the network property is thus made by the switch92.

On the other hand, the network property may be changed by propagating the new value of the network property through the network from a source network object. In the example ofFIG. 11, virtual NIC A86determines that a property or event has changed inside the network (e.g., the MTU), and the virtual NIC A86pushes the new property or event through a control message104(FIGS. 4,5) to the switch92. The switch92, in turn, pushes the new property or event through a control message104to all other NICs.

The data exchanges described with respect toFIGS. 10 and 11becomes important in the implementation of the invention because the MTU of the network100can change drastically depending on the switch92to which the virtual NIC86,88is connected. For example, the MTU of the switch92when connecting partitions1and2inFIG. 3might be 64K. However, if a physical NIC96is added to the switch92then the MTU of network100must be dropped to 1500 bytes, therefore necessitating the need to update the MTU in the virtual NICs86,88of partitions1and2.

Those skilled in the art will appreciate that, in virtual environments, the pipes and communication paths described herein may be hardwired connections or virtual connections implemented as a software virtual bus connection between partitions. A virtual bus connection models a hardware bus and may provide a low level protocol for creating and destroying such communication paths that an end station may use to communicate with other partitions using the techniques described herein.

Exemplary Networked and Distributed Environments

One of ordinary skill in the art can appreciate that the invention can be implemented in connection with any suitable host computer or other client or server device, which can be deployed as part of a computer network, or in a distributed computing environment. In this regard, the invention pertains to any computer system or environment having any number of memory or storage units, and any number of applications and processes occurring across any number of storage units or volumes, which may be used in connection with virtualizing a guest OS in accordance with the invention. The invention may apply to an environment with server computers and client computers deployed in a network environment or distributed computing environment, having remote or local storage. The invention may also be applied to standalone computing devices, having programming language functionality, interpretation and execution capabilities for generating, receiving and transmitting information in connection with remote or local services.

Distributed computing provides sharing of computer resources and services by exchange between computing devices and systems. These resources and services include the exchange of information, cache storage and disk storage for files. Distributed computing takes advantage of network connectivity, allowing clients to leverage their collective power to benefit the entire enterprise. In this regard, a variety of devices may have applications, objects or resources that may implicate the processes of the invention.

FIG. 12Aprovides a schematic diagram of an exemplary networked or distributed computing environment. The distributed computing environment comprises computing objects100a,100b, etc. and computing objects or devices110a,110b,110c, etc. These objects may comprise programs, methods, data stores, programmable logic, etc. The objects may comprise portions of the same or different devices such as PDAs, audio/video devices, MP3 players, personal computers, etc. Each object can communicate with another object by way of the communications network120. This network may itself comprise other computing objects and computing devices that provide services to the system ofFIG. 12A, and may itself represent multiple interconnected networks. In accordance with an aspect of the invention, each object100a,100b, etc. or110a,110b,110c, etc. may contain an application that might make use of an API, or other object, software, firmware and/or hardware, to request use of the virtualization processes of the invention.

It can also be appreciated that an object, such as110c, may be hosted on another computing device100a,100b, etc. or110a,110b, etc. Thus, although the physical environment depicted may show the connected devices as computers, such illustration is merely exemplary and the physical environment may alternatively be depicted or described comprising various digital devices such as PDAs, televisions, MP3 players, etc., software objects such as interfaces, COM objects and the like.

There are a variety of systems, components, and network configurations that support distributed computing environments. For example, computing systems may be connected together by wired or wireless systems, by local networks or widely distributed networks. Currently, many of the networks are coupled to the Internet, which provides an infrastructure for widely distributed computing and encompasses many different networks. Any of the infrastructures may be used for exemplary communications made incident to the virtualization processes of the invention.

In home networking environments, there are at least four disparate network transport media that may each support a unique protocol, such as Power line, data (both wireless and wired), voice (e.g., telephone) and entertainment media. Most home control devices such as light switches and appliances may use power lines for connectivity. Data Services may enter the home as broadband (e.g., either DSL or Cable modem) and are accessible within the home using either wireless (e.g., HomeRF or 802.11B) or wired (e.g., Home PNA, Cat 5, Ethernet, even power line) connectivity. Voice traffic may enter the home either as wired (e.g., Cat 3) or wireless (e.g., cell phones) and may be distributed within the home using Cat 3 wiring. Entertainment media, or other graphical data, may enter the home either through satellite or cable and is typically distributed in the home using coaxial cable. IEEE 1394 and DVI are also digital interconnects for clusters of media devices. All of these network environments and others that may emerge as protocol standards may be interconnected to form a network, such as an intranet, that may be connected to the outside world by way of the Internet. In short, a variety of disparate sources exist for the storage and transmission of data, and consequently, moving forward, computing devices will require ways of sharing data, such as data accessed or utilized incident to program objects, which make use of the virtualized services in accordance with the invention.

The Internet commonly refers to the collection of networks and gateways that utilize the TCP/IP suite of protocols, which are well-known in the art of computer networking. TCP/IP is an acronym for “Transmission Control Protocol/Internet Protocol.” The Internet can be described as a system of geographically distributed remote computer networks interconnected by computers executing networking protocols that allow users to interact and share information over the network(s). Because of such wide-spread information sharing, remote networks such as the Internet have thus far generally evolved into an open system for which developers can design software applications for performing specialized operations or services, essentially without restriction.

Thus, the network infrastructure enables a host of network topologies such as client/server, peer-to-peer, or hybrid architectures. The “client” is a member of a class or group that uses the services of another class or group to which it is not related. Thus, in computing, a client is a process, i.e., roughly a set of instructions or tasks, that requests a service provided by another program. The client process utilizes the requested service without having to “know” any working details about the other program or the service itself. In a client/server architecture, particularly a networked system, a client is usually a computer that accesses shared network resources provided by another computer, e.g., a server. In the example ofFIG. 12A, computers110a,110b, etc. can be thought of as clients and computers100a,100b, etc. can be thought of as the server where server100a,100b, etc. maintains the data that is then replicated in the client computers110a,110b, etc., although any computer can be considered a client, a server, or both, depending on the circumstances. Any of these computing devices may be processing data or requesting services or tasks that may implicate an implementation of the architectures of the invention.

A server is typically a remote computer system accessible over a remote or local network, such as the Internet. The client process may be active in a first computer system, and the server process may be active in a second computer system, communicating with one another over a communications medium, thus providing distributed functionality and allowing multiple clients to take advantage of the information-gathering capabilities of the server. Any software objects utilized pursuant to making use of the virtualized architecture(s) of the invention may be distributed across multiple computing devices or objects.

Client(s) and server(s) communicate with one another utilizing the functionality provided by protocol layer(s). For example, HyperText Transfer Protocol (HTTP) is a common protocol that is used in conjunction with the World Wide Web (WWW), or “the Web.” Typically, a computer network address such as an Internet Protocol (IP) address or other reference such as a Universal Resource Locator (URL) can be used to identify the server or client computers to each other. The network address can be referred to as a URL address. Communication can be provided over a communications medium, e.g., client(s) and server(s) may be coupled to one another via TCP/IP connection(s) for high-capacity communication.

FIG. 12Aillustrates an exemplary networked or distributed environment, with a server in communication with client computers via a network/bus, in which the invention may be employed. In more detail, a number of servers100a,100b, etc., are interconnected via a communications network/bus120, which may be a LAN, WAN, intranet, the Internet, etc., with a number of client or remote computing devices110a,110b,110c,110d,110e, etc., such as a portable computer, handheld computer, thin client, networked appliance, or other device, such as a VCR, TV, oven, light, heater and the like. It is thus contemplated that the invention may apply to any computing device in connection with which it is desirable to implement guest interfaces and operating systems in accordance with the invention.

In a network environment in which the communications network/bus120is the Internet, for example, the servers100a,110b, etc. can be Web servers with which the clients110a,110b,110c,110d,110e, etc. communicate via any of a number of known protocols such as HTTP. Servers100a,100b, etc. may also serve as clients110a,110b,110c,110d,110e, etc., as may be characteristic of a distributed computing environment.

Communications may be wired or wireless, where appropriate. Client devices110a,110b,110c,110d,110e, etc. may or may not communicate via communications network/bus120, and may have independent communications associated therewith. For example, in the case of a TV or VCR, there may or may not be a networked aspect to the control thereof. Each client computer110a,110b,110c,110d,110e, etc. and server computer100a,100b, etc. may be equipped with various application program modules or objects130and with connections or access to various types of storage elements or objects, across which files or data streams may be stored or to which portion(s) of files or data streams may be downloaded, transmitted or migrated. Any one or more of computers100a,100b,110a,110b, etc. may be responsible for the maintenance and updating of a database140or other storage element, such as a database or memory140for storing data processed according to the invention. Thus, the invention can be utilized in a computer network environment having client computers110a,110b, etc. that can access and interact with a computer network/bus120and server computers100a,100b, etc. that may interact with client computers110a,110b, etc. and other like devices, and databases140.

Exemplary Computing Device

FIG. 12Band the following discussion are intended to provide a brief general description of a suitable host computing environment in connection with which the invention may be implemented. It should be understood, however, that handheld, portable and other computing devices and computing objects of all kinds are contemplated for use in connection with the invention. While a general purpose computer is described below, this is but one example, and the invention may be implemented with a thin client having network/bus interoperability and interaction. Thus, the invention may be implemented in an environment of networked hosted services in which very little or minimal client resources are implicated, e.g., a networked environment in which the client device serves merely as an interface to the network/bus, such as an object placed in an appliance. In essence, anywhere that data may be stored or from which data may be retrieved or transmitted to another computer is a desirable, or suitable, environment for operation of the virtualization techniques in accordance with the invention.

Although not required, the invention can be implemented in whole or in part via an operating system, for use by a developer of services for a device or object, and/or included within application software that operates in connection with the virtualized OS of the invention. Software may be described in the general context of computer-executable instructions, such as program modules, being executed by one or more computers, such as client workstations, servers or other devices. Generally, program modules include routines, programs, objects, components, data structures and the like that perform particular tasks or implement particular abstract data types. Typically, the functionality of the program modules may be combined or distributed as desired in various embodiments. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations and protocols. Other well known computing systems, environments, and/or configurations that may be suitable for use with the invention include, but are not limited to, personal computers (PCs), automated teller machines, server computers, hand-held or laptop devices, multi-processor systems, microprocessor-based systems, programmable consumer electronics, network PCs, appliances, lights, environmental control elements, minicomputers, mainframe computers and the like. As noted above, the invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network/bus or other data transmission medium. In a distributed computing environment, program modules may be located in both local and remote computer storage media including memory storage devices, and client nodes may in turn behave as server nodes.

FIG. 12Billustrates an example of a suitable host computing system environment150in which the invention may be implemented, although as made clear above, the host computing system environment150is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment150be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment150.

With reference toFIG. 12B, an exemplary system for implementing the invention includes a general purpose computing device in the form of a computer160. Components of computer160may include, but are not limited to, a processing unit162, a system memory164, and a system bus166that couples various system components including the system memory to the processing unit162. The system bus166may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, Peripheral Component Interconnect (PCI) bus (also known as Mezzanine bus), and PCI Express (PCIe).

The system memory164includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM)168and random access memory (RAM)170. A basic input/output system172(BIOS), containing the basic routines that help to transfer information between elements within computer160, such as during start-up, is typically stored in ROM168. RAM170typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit162. By way of example, and not limitation,FIG. 12Billustrates operating system174, application programs176, other program modules178, and program data180.

The computer160may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only,FIG. 12Billustrates a hard disk drive182that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive184that reads from or writes to a removable, nonvolatile magnetic disk186, and an optical disk drive188that reads from or writes to a removable, nonvolatile optical disk190, such as a CD-ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM and the like. The hard disk drive182is typically connected to the system bus166through a non-removable memory interface such as interface192, and magnetic disk drive184and optical disk drive188are typically connected to the system bus166by a removable memory interface, such as interface194.

The drives and their associated computer storage media discussed above and illustrated inFIG. 12Bprovide storage of computer readable instructions, data structures, program modules and other data for the computer160. InFIG. 12B, for example, hard disk drive182is illustrated as storing operating system196, application programs198, other program modules200and program data202. Note that these components can either be the same as or different from operating system174, application programs176, other program modules178and program data180. Operating system196, application programs198, other program modules200and program data202are given different numbers here to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer160through input devices such as a keyboard204and pointing device206, commonly referred to as a mouse, trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit162through a user input interface208that is coupled to the system bus166, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). These are the kinds of structures that are virtualized by the architectures of the invention. A graphics interface210, such as one of the interfaces implemented by the Northbridge, may also be connected to the system bus166. Northbridge is a chipset that communicates with the CPU, or host processing unit162, and assumes responsibility for communications such as PCI, PCIe and accelerated graphics port (AGP) communications. One or more graphics processing units (GPUs)212may communicate with graphics interface210. In this regard, GPUs212generally include on-chip memory storage, such as register storage and GPUs212communicate with a video memory214. GPUs212, however, are but one example of a coprocessor and thus a variety of coprocessing devices may be included in computer160, and may include a variety of procedural shaders, such as pixel and vertex shaders. A monitor216or other type of display device is also connected to the system bus166via an interface, such as a video interface218, which may in turn communicate with video memory214. In addition to monitor216, computers may also include other peripheral output devices such as speakers220and printer222, which may be connected through an output peripheral interface224.

The computer160may operate in a networked or distributed environment using logical connections to one or more remote computers, such as a remote computer226. The remote computer226may be a personal computer, a server, a router, a network PC, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer160, although only a memory storage device228has been illustrated inFIG. 12B. The logical connections depicted inFIG. 12Binclude a local area network (LAN)230and a wide area network (WAN)232, but may also include other networks/buses. Such networking environments are commonplace in homes, offices, enterprise-wide computer networks, intranets and the Internet.

When used in a LAN networking environment, the computer160is connected to the LAN230through a network interface or adapter234. When used in a WAN networking environment, the computer160typically includes a modem236or other means for establishing communications over the WAN232, such as the Internet. The modem236, which may be internal or external, may be connected to the system bus166via the user input interface208, or other appropriate mechanism. In a networked environment, program modules depicted relative to the computer160, or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation,FIG. 12Billustrates remote application programs238as residing on memory device228. It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used.

There are multiple ways of implementing the invention, e.g., an appropriate API, tool kit, driver code, operating system, control, standalone or downloadable software object, etc. which enables applications and services to use the virtualized architecture(s), systems and methods of the invention. The invention contemplates the use of the invention from the standpoint of an API (or other software object), as well as from a software or hardware object that receives any of the aforementioned techniques in accordance with the invention. Thus, various implementations of the invention described herein may have aspects that are wholly in hardware, partly in hardware and partly in software, as well as in software.

As mentioned above, while exemplary embodiments of the invention have been described in connection with various computing devices and network architectures, the underlying concepts may be applied to any computing device or system in which it is desirable to emulate guest software. For instance, the various algorithm(s) and hardware implementations of the invention may be applied to the operating system of a computing device, provided as a separate object on the device, as part of another object, as a reusable control, as a downloadable object from a server, as a “middle man” between a device or object and the network, as a distributed object, as hardware, in memory, a combination of any of the foregoing, etc. One of ordinary skill in the art will appreciate that there are numerous ways of providing object code and nomenclature that achieves the same, similar or equivalent functionality achieved by the various embodiments of the invention.

The methods and apparatus of the invention may also be practiced via communications embodied in the form of program code that is transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via any other form of transmission, wherein, when the program code is received and loaded into and executed by a machine, such as an EPROM, a gate array, a programmable logic device (PLD), a client computer, etc., the machine becomes an apparatus for practicing the invention. When implemented on a general-purpose processor, the program code combines with the processor to provide a unique apparatus that operates to invoke the functionality of the invention. Additionally, any storage techniques used in connection with the invention may invariably be a combination of hardware and software.

While the invention has been described in connection with the preferred embodiments of the various figures, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiment for performing the same function of the invention without deviating therefrom. For example, while exemplary network environments of the invention are described in the context of a networked environment, such as a peer to peer networked environment, one skilled in the art will recognize that the invention is not limited thereto, and that the methods, as described in the present application may apply to any computing device or environment, such as a gaming console, handheld computer, portable computer, etc., whether wired or wireless, and may be applied to any number of such computing devices connected via a communications network, and interacting across the network. Furthermore, it should be emphasized that a variety of computer platforms, including handheld device operating systems and other application specific operating systems are contemplated, especially as the number of wireless networked devices continues to proliferate.

While exemplary embodiments refer to utilizing the invention in the context of a guest OS virtualized on a host OS, the invention is not so limited, but rather may be implemented to virtualize a second specialized processing unit cooperating with a main processor for other reasons as well. Moreover, the invention contemplates the scenario wherein multiple instances of the same version or release of an OS are operating in separate virtual machines according to the invention. It can be appreciated that the virtualization of the invention is independent of the operations for which the guest OS is used. It is also intended that the invention applies to all computer architectures, not just the Windows architecture. Still further, the invention may be implemented in or across a plurality of processing chips or devices, and storage may similarly be effected across a plurality of devices. Therefore, the invention should not be limited to any single embodiment, but rather should be construed in breadth and scope in accordance with the appended claims.