Method and apparatus for emulating an input/output unit when transferring data over a network

• US 6,421,742 B1
• Filed: 10/29/1999
• Issued: 07/16/2002
• Est. Priority Date: 10/29/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Tillier, Fabian S.
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Mai, Rijue
• Application Number:
  US09/430,308
• Time in Patent Office: 991 Days
• Field of Search: 710/1, 710/4, 710/5, 710/7, 710/11, 710/15, 710/20, 710/33, 710/35, 710/36, 710/52, 710/61, 710/65, 710/128, 709/200, 709/201, 709/232
• US Class Current: 710/1
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 69/08 Protocols for interworking; Protocol conversion
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

In an example embodiment, a method of transferring data to or from an input/output unit across a network emulates a message passing protocol. A message sent from a host device to the input/output unit specifies the requested data transfer and is formatted in accordance with the message passing protocol. An emulation service software layer on the input/output unit translates the message into a corresponding series of data transfer operation instructions. The series of data transfer operation instructions have a different format than the format of the message passing protocol. The data transfer specified by the message is carried out by the operating system and hardware of a target device in the input/output unit using the series of data transfer operation instructions. After the data transfer is completed, a reply message is created in the emulation service software layer and the reply message is sent to the host device in a format according to the message passing protocol.

Claims

1. A method of transferring data to or from an input/output unit across a network, said method comprising:

sending a message from a host device to said input/output unit, said message specifying a requested data transfer and being formatted in accordance with a message passing protocol;

in an emulation service software layer on said input/output unit, translating said message into a corresponding series of data transfer operation instructions, said series of data transfer operation instructions being of a format other than said message passing protocol;

performing said data transfer specified by said message in the operating system and hardware of a target device in the input/output unit using said series of data transfer operation instructions;

upon completion of the data transfer, creating a reply message in said emulation service software layer and sending said reply message to said host device in a format according to said message passing protocol.

2. The method recited in claim 1, wherein said series of data transfer operation instructions identifies and maps a set of buffers in the input/output unit which are utilized when performing the data transfer.

3. The method recited in claim 2, wherein the set of buffers are unmapped after the reply message is sent to said host device.

4. The method recited in claim 1, wherein the message specifying a requested data transfer is formatted in accordance with the message passing protocol by a module in the operating system of the host device.

5. The method recited in claim 4, wherein the operating system of the host device sends a completion notification to a user application utilizing a non-blocking, asynchronous usage model operating in kernel space.

6. The method recited in claim 5, wherein the data transfer is made over a virtual interface of the network.

7. The method recited in claim 6, wherein the message passing protocol is compliant with Version 1.5 of I₂O.

8. An input/output unit connected to a host device across a network, said input/output unit configured to carry out a data transfer method in response to a message from the host device comprising:

receiving a message sent from a host device, said message specifying a requested data transfer and being formatted in accordance with a message passing protocol;

in an emulation service software layer, translating said message into a corresponding series of data transfer operation instructions, said series of data transfer operation instructions being of a format other than said message passing protocol;

performing said data transfer specified by said message in the operating system and hardware of a target device using said series of data transfer operation instructions;

upon completion of the data transfer, creating a reply message in said emulation service software layer and sending said reply message to said host device in a format according to said message passing protocol.

9. The input/output unit recited in claim 8, wherein said series of data transfer operation instructions identifies and maps a set of buffers which are utilized when performing the data transfer.

10. The input/output unit recited in claim 9, wherein the set of buffers are unmapped after the reply message is sent to said host device.

11. The input/output unit recited in claim 8, wherein the data transfer is made over a virtual interface between the input/output unit and the network.

12. The input/output unit recited in claim 11, wherein the data is transferred directly between the input/output unit and the memory of a host device over a virtual interface without making an intermediate copy of the data.

13. The input/output unit recited in claim 12, wherein the input/output unit further comprises a software stack having transport layers to effectuate the transfer of data across the network and the translation of the message is transparent to the transport layers.

14. The input/output unit recited in claim 13, wherein the input/output unit comprises a storage adapter having a plurality of block storage data recording media.

15. A tangible medium storing a plurality of program instructions, said program instructions causing an input/output unit to transfer data with a host device across a network, the data transfer comprising:

receiving a message sent from a host device, said message specifying a requested data transfer and being formatted in accordance with a message passing protocol;

in an emulation service software layer, translating said message into a corresponding series of data transfer operation instructions, said series of data transfer operation instructions being of a format other than said message passing protocol;

performing said data transfer specified by said message in the operating system and hardware of a target device using said series of data transfer operation instructions;

upon completion of the data transfer, creating a reply message in said emulation service software layer and sending said reply message to said host device in a format according to said message passing protocol.

16. The tangible medium recited in claim 15, wherein said series of data transfer operation instructions identifies and maps a set of buffers in the input/output unit which are utilized when performing the data transfer.

17. The tangible medium recited in claim 16, wherein the set of buffers are unmapped after the reply message is sent to said host device.

18. The tangible medium recited in claim 15, wherein the data transfer is made over a virtual interface between the input/output unit and the network.

19. The tangible medium recited in claim 18, wherein the data is transferred directly between the input/output unit and the memory of a host device over a virtual interface without making an intermediate copy of the data.

20. The tangible medium recited in claim 19, wherein the input/output unit further comprises a software stack having transport layers to effectuate the transfer of data across the network and the translation of the message is transparent to the transport layers.