Abstract: Methods and systems for protocol offload and direct I/O with I/O sharing in a virtualized network environment are disclosed. Aspects of one method may include a plurality of GOSs sharing a single network interface circuitry, or a network interface card, (NIC) that may provide access to a network. The NIC may directly handle processing of data to be transmitted to the network and/or data received from the network for each of the GOSs without a TGOS for the GOSs handling the data to be transmitted to the network and/or data received from the network. The data may be copied directly from a buffer in the single NIC to an application buffer for one of the plurality of GOSs and/or directly from an application buffer for one of the plurality of GOSs to the buffer in the single NIC.

Abstract: Methods and systems for direct device access are disclosed. Aspects of one method may include a plurality of GOSs directly accessing a first network interface device, where the first network interface device may provide access to a network. One or more of the GOSs may be migrated to directly access a second network interface device, based on state information for each of the GOSs, where the state information may be maintained by the host. The GOSs may communicate data to a device coupled to the network by direct accessing the first and/or second network interface device. Similarly, the first and/or second network interface device may communicate data received from a device coupled to the network to one or more of the plurality of GOSs via direct access of the first and/or second network interface device.

Abstract: A network interface device for use with a host computer that includes a host processor and a memory, and which is configured to concurrently run a master operating system and at least one virtual operating system. The device includes a bus interface that communicates over a bus with the host processor and the memory, and a network interface, which is coupled to send and receive data packets carrying data over a packet network. A protocol processor is coupled between the bus interface and the network interface so as to convey the data between the network interface and the memory while performing protocol processing on the data packets under instructions from the at least one virtual operating system, while bypassing the master operating system.

Abstract: Certain aspects of a method and system for transparent transmission control protocol (TCP) offload with best effort direct placement of incoming traffic are disclosed. Aspects of a method may include collecting TCP segments in a network interface card (NIC) processor without transferring state information to a host processor every time a TCP segment is received. When an event occurs that terminates the collection of TCP segments, the NIC processor may generate a new aggregated TCP segment based on the collected TCP segments. If a placement sequence number corresponding to the generated new TCP segment for the particular network flow is received before the TCP segment is received, the generated new TCP segment may be transferred directly from the memory to the user buffer instead of transferring the data to a kernel buffer, which would require further copy by the host stack from kernel buffer to user buffer.

Abstract: Certain aspects of a method and system for protocol offload in paravirtualized systems may be disclosed. Exemplary aspects of the method may include preposting of application buffers to a front-end driver rather than to a NIC in a paravirtualized system. The NIC may be enabled to place the received offloaded data packets into a received data buffer corresponding to a particular guest operating system (GOS). A back-end driver may be enabled to acknowledge the placed offloaded data packets. The back-end driver may be enabled to forward the received data buffer corresponding to the particular GOS to the front-end driver. The front-end driver may be enabled to copy offloaded data packets from a received data buffer corresponding to a particular GOS to the preposted application buffers.

Abstract: Certain aspects of a method and system for transparent transmission control protocol (TCP) offload are disclosed. Aspects of a method may include collecting TCP segments in a network interface card (NIC) processor without transferring state information to a host system. The collected TCP segments may be buffered in a coalescer. The coalescer may verify that the network flow associated with the collected TCP segments has an entry in a flow lookup table (FLT). When the FLT is full, the coalescer may close a current entry and assign the network flow to the available entry. The coalescer may also update information in the FLT. When an event occurs that terminates the collection of TCP segments, the coalescer may generate a single aggregated TCP segment based on the collected TCP segments. The aggregated TCP segment and state information may be communicated to the host system for processing.

Abstract: A method for processing a datagram, including receiving an initial fragment of the datagram over a communication link and classifying in an initial classification the initial fragment as a first fragment, a middle fragment, or a last fragment of the datagram. The method further includes receiving one or more subsequent fragments over the communication link, following the initial fragment, and classifying each of the one or more subsequent fragments in respective subsequent classifications so as to find among the subsequent fragments at least one of the first fragment, the middle fragment, and the last fragment of the datagram. Responsive to the initial and the one or more subsequent classifications, a determination is made whether the datagram is completely constituted by the initial fragment and no more than two of the subsequent fragments. The datagram is reassembled responsive to the determination.

Abstract: Certain aspects of a method and system for transparent TCP offload with a user space library are disclosed. Aspects of a method may include collecting TCP segments in a network interface card (NIC) without transferring state information to a host system. When an event occurs that terminates the collection of TCP segments, a single aggregated TCP segment based on the collected TCP segments may be generated. The aggregated TCP segment may be posted directly to a user space library, bypassing kernel processing of the aggregated TCP segment.

Abstract: Certain aspects of a method and system for protocol offload in paravirtualized systems may be disclosed. Exemplary aspects of the method may include preposting of application buffers to a front-end driver rather than to a NIC in a paravirtualized system. The NIC may be enabled to place the received offloaded data packets into a received data buffer corresponding to a particular GOS. A back-end driver may be enabled to acknowledge the placed offloaded data packets. The back-end driver may be enabled to forward the received data buffer corresponding to the particular GOS to the front-end driver. The front-end driver may be enabled to copy offloaded data packets from a received data buffer corresponding to a particular guest operating system (GOS) to the preposted application buffers.

Abstract: A network interface device includes a bus interface that communicates over a bus with a host processor and memory, and a network interface that sends and receive data packets carrying data over a packet network. A protocol processor conveys the data between the network interface and the memory via the bus interface while performing protocol offload processing on the data packets in accordance with multiple different application flows. The bus interface queues the data for transmission over the bus in a plurality of queues that are respectively assigned to the different application flows, and transmits the data over the bus according to the queues.

Abstract: A method for communication is disclosed and may include, in a network interface device, parsing a portion of a TCP segment into one or more portions of Internet Small Computer Systems Interface (iSCSI) Protocol Data Units (PDUs). A header and/or a payload for one or more of the parsed iSCSI PDUs may be recovered. Concurrent with parsing of a remaining portion of the TCP segment to recover a remaining portion of PDUs, the recovered header may be evaluated and/or the recovered payload may be routed external to the network interface device for processing. The evaluating and the routing may occur independently of the parsing within the network interface device. Respective separate physical processors may be used for the parsing and the recovering. The respective separate processors for recovering may be used for the evaluating and the routing.

Abstract: Certain aspects of a method and system for transparent transmission control protocol (TCP) offload with transmit and receive coupling are disclosed. Aspects of a method may include collecting at least one received TCP segment for a determined network flow via a network interface card (NIC) processor. The state information for the received TCP segment and state information for transmitted TCP segments for the determined network flow may be stored at the NIC without transferring state information for the received TCP segment and the state information for the transmitted TCP segments to a host system communicatively coupled to the NIC. A new TCP segment comprising the collected TCP segments may be generated after a termination event occurs. The generated new TCP segment, new state information for the generated new TCP segment, and the state information for the transmitted TCP segments may be communicated to the host system for TCP offload.

Abstract: Certain aspects of a method and system for transparent TCP offload with a user space library are disclosed. Aspects of a method may include collecting TCP segments in a network interface card (NIC) without transferring state information to a host system. When an event occurs that terminates the collection of TCP segments, a single aggregated TCP segment based on the collected TCP segments may be generated. The aggregated TCP segment may be posted directly to a user space library, bypassing kernel processing of the aggregated TCP segment.

Abstract: Methods and systems for zero copy in a virtualized network environment are disclosed. Aspects of one method may include a plurality of GOSs that share a single NIC. The NIC may switch communication to a GOS to allow that GOS access to a network via the NIC. The NIC may offload, for example, OSI layer 3, 4, and/or 5 protocol operations from a host system and/or the GOSs. The data received from, or to be transmitted to, the network by the NIC may be copied directly between the NIC's buffer and a corresponding application buffer for one of the GOSs without copying the data to a TGOS. The NIC may access the GOS buffer via a virtual address, a buffer offset, or a physical address. The virtual address and the buffer offset may be translated to a physical address.

Abstract: Certain aspects of a method and system for protocol offload in paravirtualized systems may be disclosed. Exemplary aspects of the method may include preposting of application buffers to a front-end driver rather than to a NIC in a paravirtualized system. The NIC may be enabled to place the received offloaded data packets into a received data buffer corresponding to a particular GOS. A back-end driver may be enabled to acknowledge the placed offloaded data packets. The back-end driver may be enabled to forward the received data buffer corresponding to the particular GOS to the front-end driver. The front-end driver may be enabled to copy offloaded data packets from a received data buffer corresponding to a particular guest operating system (GOS) to the preposted application buffers.

Abstract: Certain aspects of a method and system for transparent TCP offload with a user space library are disclosed. Aspects of a method may include collecting TCP segments in a network interface card (NIC) without transferring state information to a host system. When an event occurs that terminates the collection of TCP segments, a single aggregated TCP segment based on the collected TCP segments may be generated. The aggregated TCP segment may be posted directly to a user space library, bypassing kernel processing of the aggregated TCP segment.

Abstract: A method for a receiver to perform processing of incoming data segments transmitted over a network by a transmitter in accordance with a transport protocol. The segments incorporate sequence values indicative of a transmission order of the segments. The method consists of receiving the data segments over the network in a reception order. Then, for each segment received in the reception order, the sequence values of the received segment and of the segments received earlier in the reception order are compared in order to assign the received segment a classification identity as an in-order or out-of-order segment. The method further includes writing the segments, in a writing order that is substantially identical to the reception order, to respective locations in an output buffer responsive to the classification identity of each segment, so that the segments in the output buffer are arranged in the transmission order.

Abstract: Certain aspects of a method and system for protocol offload in paravirtualized systems may be disclosed. Exemplary aspects of the method may include preposting of application buffers to a front-end driver rather than to a NIC in a paravirtualized system. The NIC may be enabled to place the received offloaded data packets into a received data buffer corresponding to a particular GOS. A back-end driver may be enabled to acknowledge the placed offloaded data packets. The back-end driver may be enabled to forward the received data buffer corresponding to the particular GOS to the front-end driver. The front-end driver may be enabled to copy offloaded data packets from a received data buffer corresponding to a particular guest operating system (GOS) to the preposted application buffers.

Abstract: A network interface device includes a bus interface that communicates over a bus with a host processor and memory, and a network interface that sends and receive data packets carrying data over a packet network. A protocol processor conveys the data between the network interface and the memory via the bus interface while performing protocol offload processing on the data packets in accordance with multiple different application flows. The bus interface queues the data for transmission over the bus in a plurality of queues that are respectively assigned to the different application flows, and transmits the data over the bus according to the queues.

Abstract: A network interface device includes a bus interface that communicates over a bus with a host processor and memory, and a network interface, including at least first and second physical ports, which are coupled to send and receive data packets carrying data over a packet network. A protocol processor includes a single transmit processing pipeline and a single receive processing pipeline, which are coupled between the bus interface and the network interface so as to convey the data between both of the first and second physical ports of the network interface and the memory via the bus interface while performing protocol offload processing on the data packets.