Access assurance for remote memory access over network

• US 6,804,673 B2
• Filed: 04/19/2001
• Issued: 10/12/2004
• Est. Priority Date: 04/19/2001
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Miyoshi, Takashi, Horie, Takeshi, Sugahara, Hirohide, Larson, Jeffrey D.
• Primary Examiner(s): Le, Uyen
• Assistant Examiner(s): GODDARD, BRIAN D
• Application Number:
  US09/839,954
• Publication Number:
  US 20030009432A1
• Time in Patent Office: 1,272 Days
• Field of Search: 707/10, 707/1, 707/8, 707/2, 709/212, 710/22-28, 710/308
• US Class Current: 1/1
• CPC Class Codes: G06F 13/387 for adaptation of different data processing systems to different peripheral devices, e.g. protocol converters for incompatible systems, open system
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing

Abstract

A method and system provide access assurance regarding an RDMA transaction. The system comprises an initiating device and a target device placed across a network. The initiating device and the target device are coupled to a first and a second buses, respectively. The first and the second buses are coupled to the network router through a first and a second network adaptors. An RDMA space and an associated access assurance space are assigned to the target device in the memory space of the first bus. The initiating device may RDMA the target device by directly reading from or writing into the RDMA space assigned to the target device. To obtain access assurance information regarding the RDMA transaction, the initiator performs a read from the assurance space associated with the RDMA space of the target device in the memory space of the first bus.

Claims

1. A method for a first computer device to obtain access assurance information regarding a remote direct memory access transaction directed to a second computer device over a computer network, the first computer device being coupled to a bus, and a network adaptor being coupled between the bus and the computer network, the method comprising:

providing an access space within a memory space of the bus, the access space storing a first range of addresses associated with the network adaptor, and the network adaptor configured to process a transaction having a target address within the first range of addresses as the remote direct memory access transaction directed to the second computer device over the computer network;

providing an assurance space within the memory space of the bus, the assurance space storing a second range of addresses associated with the network adaptor; and

reading from the assurance space, the network adaptor configured to return the access assurance information regarding the remote direct memory access transaction to the first computer device in response to reading from the assurance space.

2. The method of claim 1, wherein the access assurance information is received by the network adaptor in a response packet associated with the remote direct memory access transaction and is stored in the network adaptor.

3. The method of claim 2 wherein the access assurance information is stored in the network adaptor until the first computer device performs an assurance check to obtain the access assurance information.

4. The method of claim 1, wherein the target address includes a node identification field, an assurance field, and an address offset, and reading from the assurance space comprises:

posting a read command on the bus with a read address including a same node identification field and a same address offset as those of the target address but a different assurance field from that of the target address.

5. A system for enabling a first device to obtain access assurance information regarding a remote direct memory access transaction directed to a second device over a computer network, comprising:

a first PCI bus coupled to the first device, the first PCI bus including an access space and an assurance space; and

a first PCI network adaptor coupled between the first PCI bus and the computer network, the access space storing a first range of addresses associated with the first PCI network adaptor, the first PCI network adaptor being configured to process a transaction having a target address within the first range of addresses as the remote direct memory access transaction and to receive the access assurance information corresponding to the remote direct memory transaction over the computer network, the assurance space storing a second range of addresses associated with the first PCI network adaptor, and the first PCI network adaptor configured to return the access assurance information to the first device in response to reading from the assurance space.

6. The system of claim 5, wherein the first PCI network adaptor comprises:

a PCI interface target unit coupled to the first PCI bus, and configured to recognize and receive the remote direct memory access transaction in response to a determination that the target address is within the first range of addresses

at least one buffer; and

a PCI target control unit coupled between the PCI interface target unit and the at least one buffer, and configured to form at least one block queue of data associated with the remote direct memory access transaction in the at least one buffer.

7. The system of claim 6, wherein the PCI target control unit comprises a first memory unit configured to store a memory location of the queued data associated with the remote direct memory access transaction in the at least one buffer, and a second memory unit configured to store the access assurance information corresponding to the remote direct memory access transaction.

8. The system of claim 7, wherein the access assurance information in the second memory unit is indexed by the memory location of the queued data associated with the remote direct memory access transaction.

9. The system of claim 7, further comprising:

a second PCI bus coupled to the second device; and

a second PCI network adaptor coupled between the second PCI bus and the computer network, and configured to process the remote direct memory access transaction, to determine the access assurance information corresponding to the remote direct memory access transaction, and to send the access assurance information to the first PCI network adaptor over the computer network.

10. The system of claim 9, wherein the second PCI network adaptor comprises:

a master access buffer configured to determine address information associated with the remote direct memory access transaction; and

a PCI interface master unit coupled between the master access buffer and the second PCI bus, and configured to translate the address information into a PCI address and to post the remote direct memory access transaction on the second PCI bus with the PCI address.

11. The system of claim 10, wherein the PCI interface master unit determines the access assurance information corresponding to the remote direct memory access transaction, forms a response packet including the access assurance information, and sends the response packet to the first PCI network adaptor over the computer network according to the address information.

12. The system of claim 5, wherein the remote direct memory access transaction comprises a write transaction.

13. A system for enabling a first device to obtain access assurance information corresponding to a remote direct memory access transaction directed to second device over a computer network, comprising:

a bus coupled to the first device, the bus including an access space and an assurance space;

a network adaptor coupled between the bus and the computer network for coupling the first device to the computer network, the access space storing a first range of addresses associated with the network adaptor, the network adaptor being configured to process a transaction having a target address within the first range of addresses as the remote direct memory access transaction and to receive the access assurance information corresponding to the remote direct memory transaction over the computer network, the assurance space storing a second range of addresses associated with the network adaptor, and the network adaptor configured to return the access assurance information to the first device in response to reading from the assurance space, the network adaptor comprising,

an interfacing means for recognizing and receiving the remote direct memory access transaction in response to a determination that an address associated with the remote direct memory access transaction is within the first range of addresses;

at least one buffer for queuing data associated with the remote direct memory access transaction; and

a controlling means coupled with the interfacing means for forming block queues of the data associated with the remote direct memory access transaction in the at least one buffer; and

a memory coupled with the controlling means, for storing the access assurance information received from the computer network.