Virtual memory protocol segmentation offloading

Patent metadata

Field	Value
Publication number	US-9319490-B2
Application number	US-201414568499-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Jun 9, 2008
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

Methods and systems for a more efficient transmission of network traffic are provided. According to one embodiment, payload data originated by a user process running on a host processor of the computer system is fetched by an interface of the computer system by performing direct virtual memory addressing of a user memory space of a system memory of the computer system on behalf of a network processor of the computer system. The direct virtual memory addressing maps a physical address of the payload data to a virtual address. The payload data is segmented by the network processor across one or more packets.

First claim

What is claimed is:

1. A method of performing segmentation offloading, the method comprising:
fetching, by an interface of a computer system, payload data originated by a user process running on a host processor of the computer system by performing direct virtual memory addressing of a user memory space of a system memory of the computer system on behalf of a network processor of the computer system, wherein said direct virtual memory addressing maps a physical address of the payload data to a virtual address;
segmenting, by the network processor, the payload data across one or more packets, wherein said segmenting comprises creating one or more Transmission Control Protocol (TCP) packets by performing TCP segmentation; and
storing a buffer descriptor in the system memory, the buffer descriptor containing (i) information indicative of a starting address of a payload buffer in the system memory containing at least a portion of the payload data and (ii) information indicative of whether the starting address is virtual or physical.

2. The method of claim 1 , wherein the buffer descriptor further contains information indicative of a virtual memory base address of a page directory and wherein said performing direct virtual memory addressing of a user memory space further comprises using a directory entry of the page directory identified by the starting address to translate the starting address to a physical address within the user memory space associated with the payload buffer.

3. The method of claim 1 , wherein the payload buffer is distributed among a plurality of payload buffers stored in noncontiguous physical locations of the system memory.

4. The method of claim 3 , wherein said performing direct virtual memory addressing of the user memory space further includes a scatter-gather process in which the payload data is retrieved from the plurality of payload buffers.

5. The method of claim 1 , wherein the buffer descriptor further contains information indicative of whether the starting address is a virtual address or a physical address within the user address space.

6. A non-transitory program storage device readable by one or more processors of a computer system, embodying a program of instructions executable by the one or more processors to perform a method of segmentation offloading, the method comprising:
fetching, by an interface of the computer system, payload data originated by a user process running on a host processor of the computer system by performing direct virtual memory addressing of a user memory space of a system memory of the computer system on behalf of a network processor of the computer system, wherein said direct virtual memory addressing maps a physical address of the payload data to a virtual address;
segmenting, by the network processor, the payload data across one or more packets, wherein said segmenting comprises creating one or more Transmission Control Protocol (TCP) packets by performing TCP segmentation; and
storing a buffer descriptor in system memory, the buffer descriptor containing (i) information indicative of a starting address of a payload buffer in the system memory containing at least a portion of the payload data and (ii) information indicative of whether the starting address is virtual or physical.

7. The non-transitory program storage device of claim 6 , wherein the buffer descriptor further contains information indicative of a virtual memory base address of a page directory and wherein said performing direct virtual memory addressing of a user memory space further comprises using a directory entry of the page directory identified by the starting address to translate the starting address to a physical address within the user memory space associated with the payload buffer.

8. The non-transitory program storage device of claim 6 , wherein the payload buffer is distributed among a plurality of payload buffers stored in noncontiguous physical locations of the system memory.

9. The non-transitory program storage device of claim 8 , wherein said performing direct virtual memory addressing of the user memory space further includes a scatter-gather process in which the payload data is retrieved from the plurality of payload buffers.

10. The non-transitory program storage device of claim 6 , wherein the buffer descriptor further contains information indicative of whether the starting address is a virtual address or a physical address within the user address space.

11. A method comprising:
fetching, by an interface of a computer system, payload data originated by a user process running on a host processor of the computer system by performing direct virtual memory addressing of a user memory space of a system memory of the computer system on behalf of a network processor of the computer system, wherein said direct virtual memory addressing maps a physical address of the payload data to a virtual address;
segmenting, by the network processor, the payload data across one or more packets, wherein said segmenting comprises creating one or more Transmission Control Protocol (TCP) packets by performing TCP segmentation; and
storing a plurality of buffer descriptors in the system memory, wherein the plurality of buffer descriptors include:
a first buffer descriptor of the plurality of buffer descriptors containing (i) information indicative of a first starting address of a first payload buffer in the system memory containing a first portion of the payload data and (ii) information indicative of whether the first starting address is virtual or physical; and
a second buffer descriptor of the plurality of buffer descriptors containing (i) information indicative of a second starting address of a second payload buffer in the system memory containing a second portion of the payload data and (ii) information indicative of whether the second starting address is virtual or physical.

12. The method of claim 11 , wherein the plurality of buffer descriptors further contain information indicative of a virtual memory base address of a page directory and wherein said performing direct virtual memory addressing of a user memory space further comprises using directory entries of the page directory identified by the first starting address and the second starting address, respectively, to translate the starting address to a first physical address within the user memory space associated with the first payload buffer and a second physical address within the user memory space associated with the second payload buffer.

13. The method of claim 11 , wherein the first payload buffer and the second payload buffer are stored in noncontiguous physical locations of the system memory.

14. The method of claim 13 , wherein said performing direct virtual memory addressing of the user memory space further includes a scatter-gather process in which the payload data is retrieved from the plurality of payload buffers.

15. A non-transitory program storage device readable by one or more processors of a computer system, embodying a program of instructions executable by the one or more processors to perform a method of segmentation offloading, the method comprising:
fetching, by an interface of the computer system, payload data originated by a user process running on a host processor of the computer system by performing direct virtual memory addressing of a user memory space of a system memory of the computer system on behalf of a network processor of the computer system, wherein said direct virtual memory addressing maps a physical address of the payload data to a virtual address;
segmenting, by the network processor, the payload data a

Assignees

• Fortinet Inc

Inventors

• Zhou Xu
• Chen David
• Huang Lin
• Zhang Guansong

Classifications

• G06F12/1081 Primary

  for peripheral access to main memory, e.g. direct memory access [DMA] · CPC title

• H04L47/62

  characterised by scheduling criteria · CPC title

• H04L69/166 Primary

  IP fragmentation; TCP segmentation · CPC title

• H04L49/3045

  Virtual queuing · CPC title

• G06F2212/651

  Multi-level translation tables · CPC title