Method, system, and computer program product for ethernet virtualization using an elastic FIFO memory to facilitate flow of unknown traffic to virtual hosts

• US 7,751,400 B2
• Filed: 02/25/2008
• Issued: 07/06/2010
• Est. Priority Date: 02/25/2008
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Turner, Jeffrey M., Haynie, Howard M., Hanscom, Jeffrey C.
• Primary Examiner(s): Qureshi; Afsar M.
• Application Number:
  US12/036,821
• Publication Number:
  US 20090225665A1
• Time in Patent Office: 862 Days
• Field of Search: 370230-232, 370248-422, 711/4, 711/114, 711/203, 709/220, 709/238, 700/2
• US Class Current: 370/392
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/9026 Single buffer per packet

Abstract

A packet that represents unknown traffic for a virtual host is received. A first test is performed to ascertain whether or not a destination connection can be determined for the received packet wherein, if a destination connection can be determined, a second test is performed to ascertain whether or not one or more connection-specific resources required to send the packet to a virtual host memory corresponding to the destination connection are available. If a destination connection for the packet cannot be determined, the packet is passed to a store engine. If the one or more connection-specific resources are not available, the packet is passed to the store engine. The store engine obtains a free packet buffer from a FIFO memory. The store engine moves the packet into the free packet buffer and submits the free packet buffer to the elastic FIFO memory. A monitoring procedure is performed to detect both an availability of connection-specific resources and a presence of one or more waiting packets with a known destination connection. When (i) a destination connection with one or more waiting packets, and (ii) available connection-specific resources, are both detected, removing the packet from the local data store; allocating the one or more connection-specific resources required to send the packet to the virtual host memory corresponding to the connection destination; and writing the packet to the virtual host memory.

Claims

1. A method for Ethernet virtualization using an elastic FIFO memory to facilitate flow of unknown traffic to a virtual host, the method comprising:

receiving a packet that represents unknown traffic on a network;

performing a first test to ascertain whether or not a destination connection can be determined for the received packet wherein, if a destination connection can be determined, a second test is performed to ascertain whether or not one or more connection-specific resources required to send the packet to a virtual host memory corresponding to the destination connection are available;

if a destination connection for the packet cannot be determined, passing the packet to a store engine;

if the one or more connection-specific resources are not available, passing the packet to the store engine;

the store engine obtaining a free packet buffer from an elastic first-in, first-out (FIFO) memory, wherein the free packet buffer is an empty packet-sized block of memory in a local data store;

the store engine moving the packet into the free packet buffer and submitting the free packet buffer to the elastic FIFO memory;

performing a monitoring procedure to detect both an availability of connection-specific resources and a presence of one or more waiting packets with a known destination connection;

when a destination connection with one or more waiting packets and available connection-specific resources;

are both detected, removing the packet from the local data store;

allocating the one or more connection-specific resources required to send the packet to the virtual host memory corresponding to the destination connection; and

writing the packet to the virtual host memory.

2. The method of claim 1 wherein the first test is performed by examining a header of the packet, the method further including storing the received packet in a receive buffer.

3. The method of claim 1 wherein the one or more connection-specific resources are rendered as unavailable if one or more additional packets for the destination connection already exist in the elastic FIFO memory.

4. The method of claim 1 wherein, if one or more connection-specific resources are available as determined by the second test, writing the packet to the virtual host memory.

5. The method of claim 1 wherein a destination connection is determined for and assigned to any packet that has been submitted to the elastic FIFO memory without a known destination connection.

6. The method of claim 1 wherein, when resources become available for a destination connection for which one or more connection-specific resources were previously unavailable, granting exclusive access to the one or more connection-specific resources for the destination connection.

7. The method of claim 6 further including terminating the exclusive access when no more packets for that destination connection exist in the elastic FIFO memory.

8. A system for Ethernet virtualization using an elastic FIFO memory to facilitate flow of unknown traffic to a virtual host, the system comprising:

a parser configured to receive a packet representing unknown traffic on a network and to attempt to determine a destination connection for the packet;

an allocator;

operatively coupled to the parser, the allocator configured to attempt to obtain one or more connection-specific resources required to send the packet to a virtual host memory corresponding to the destination connection, the attempting responsive to the parser determining a destination connection for the packet;

a store engine operatively coupled to the allocator, the store engine configured to receive the packet, wherein if the parser does not determine a destination connection for the packet, the parser passes the packet to the store engine and wherein, if the allocator fails in the attempt to obtain the one or more connection-specific resources, the allocator passes the packet to the store engine;

an elastic first-in, first-out (FIFO) memory operatively coupled to the store engine, the FIFO memory configured to store a free packet buffer, wherein the store engine obtains the free packet buffer from the elastic FIFO memory, and wherein the free packet buffer is an empty packet-sized block of memory in a local data store;

the store engine moving the packet into the free packet buffer and submitting the free packet buffer to the elastic FIFO memory;

a local engine configured to monitor both the allocator and the elastic FIFO memory;

the allocator being monitored for an availability of connection-specific resources, and the elastic FIFO memory being monitored for a presence of one or more waiting packets with a known destination connection;

wherein, when a destination connection with both one or more waiting packets and available connection-specific resources is monitored by the local engine, the packet is removed from the local data store and passed to the allocator; and

wherein the allocator allocates the one or more connection-specific resources required to send the packet to a virtual host memory corresponding to the destination connection; and

a send engine operatively coupled to the allocator, the send engine configured to write the packet to the virtual host memory.

9. The system of claim 8 wherein the parser is further configured to examine a header of the packet, and the system further includes a receive buffer operatively coupled to the parser configured to store the received packet.

10. The system of claim 8 wherein the one or more connection-specific resources are rendered as unavailable if one or more additional packets for the destination connection already exist in the elastic FIFO memory.

11. The system of claim 8 wherein the packet is written to the virtual host memory in response to one or more connection-specific resources being obtained by the allocator.

12. The system of claim 8 wherein a destination connection is determined for and assigned to any packet that has been submitted to the elastic FIFO memory without a known destination connection.

13. The system of claim 8 wherein, when resources are obtained for a destination connection for which one or more connection-specific resources were previously unavailable, granting exclusive access to the local engine to obtain the one or more connection-specific resources for the destination connection.

14. The system of claim 13 wherein the local engine is further configured to terminate the exclusive access when no more packets for that destination connection exist in the elastic FIFO memory.

15. A computer program product for facilitating Ethernet virtualization using an elastic FIFO memory to facilitate flow of unknown traffic to a virtual host, the computer program product comprising:

a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising;

receiving a packet that represents unknown traffic on a network;

performing a first test to ascertain whether or not a destination connection can be determined for the received packet wherein, if a destination connection can be determined, a second test is performed to ascertain whether or not one or more connection-specific resources required to send the packet to a virtual host memory corresponding to the destination connection are available;

if a destination connection for the packet cannot be determined, passing the packet to a store engine;

if the one or more connection-specific resources are not available, passing the packet to the store engine;

the store engine obtaining a free packet buffer from an elastic first-in, first-out (FIFO) memory, wherein the free packet buffer is an empty packet-sized block of memory in a local data store;

the store engine moving the packet into the free packet buffer and submitting the free packet buffer to the elastic FIFO memory;

performing a monitoring procedure to detect both an availability of connection-specific resources and a presence of one or more waiting packets with a known destination connection;

when a destination connection with one or more waiting packets and available connection-specific resources are both detected, removing the packet from the local data store;

allocating the one or more connection-specific resources required to send the packet to the virtual host memory corresponding to the destination connection destination; and

writing the packet to the virtual host memory.

16. The computer program product of claim 15 wherein the first test is performed by examining a header of the packet, and the method further comprises storing the received packet in a receive buffer.

17. The computer program product of claim 15 wherein the one or more connection-specific resources are rendered as unavailable if one or more additional packets for the destination connection already exist in the elastic FIFO memory.

18. The computer program product of claim 15 wherein, if one or more connection-specific resources are available as determined by the second test, writing the packet to the virtual host memory.

19. The computer program product of claim 15 wherein a destination connection is determined for and assigned to any packet that has been submitted to the elastic FIFO memory without a known destination connection.

20. The computer program product of claim 15 wherein, when resources become available for a destination connection for which one or more connection-specific resources were previously unavailable, granting exclusive access to the one or more connection-specific resources for the destination connection.

21. The computer program product of claim 20 wherein the method further comprises terminating the exclusive access when no more packets for that destination connection exist in the elastic FIFO memory.