Virtualization for device sharing

• US 20060253619A1
• Filed: 12/01/2005
• Published: 11/09/2006
• Est. Priority Date: 04/22/2005
• Status: Active Grant

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Torudbakken, Ola, Johnsen, Bjorn Dag
• Granted Patent: US 7,478,178 B2
• Time in Patent Office: Days
• US Class Current: 710/31
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence

Abstract

In an apparatus and method for providing device sharing, a first plurality of upstream ports are each connectable to a respective host and at least one downstream port is connectable to a device. A virtual port is defined that is associated a routing table to effect device virtualization by redirection of information packets received by the virtual port.

Claims

1. An interconnect apparatus for supporting PCI-Express, the apparatus comprising a first plurality of ports configurable as upstream ports, each connectable to a respective host, and at least one port configurable as a downstream port connectable to a device, the apparatus being operable to define a virtual port and to associate a routing table with the virtual port to effect device virtualization by redirection of information packets received by the virtual port.

2. The apparatus of claim 1, comprising a physical downstream port for linking the device with a first upstream physical port for connection to a master host and operable to provide at least one virtual downstream port for linking at least one function provided by the shared device to at least one further physical upstream port for connection to a client host.

3. The apparatus of claim 2, wherein the virtual downstream port is linked to at least one physical upstream port via a virtual bus fabric.

4. The apparatus of claim 2, wherein each virtual port is operable to present a resource provided by the device to a respective host as if the host had sole ownership of the device.

5. The apparatus of claim 2, comprising a configuration entity operable to provision device resources to a host.

6. The apparatus of claim 1, wherein a separate address range is associated with each device resource, a BAR (Bus Address Register) for a device being divided into multiple logical BARs for respective resources of the device.

7. The apparatus of claim 1, wherein the apparatus is a switch.

8. A computer system comprising a plurality of hosts, a device shared between the hosts and an interconnect apparatus for supporting PCI-Express, the interconnect apparatus comprising a first plurality of ports configurable as upstream ports, each connectable to a respective host, and at least one port configurable as a downstream port connectable to the device, the interconnect apparatus being operable to define a virtual port and to associate a routing table with the virtual port to effect device virtualization by redirection of information packets received by the virtual port.

9. The system of claim 8, comprising a configuration entity operable to provision device resources to said hosts.

10. The system of claim 9, wherein the configuration entity forms part of one of the hosts, which host acts as a master host that has access to all devices in a device tree.

11. The system of claim 10, wherein a host that is not a master host is a client host and a client host does not have access to a device resource unless the device resource is provisioned to the client host.

12. The system of claim 8, wherein a client host is operable to communicate with the configuration entity to obtain information identifying device resources provisioned to the client host.

13. The system of claim 8, wherein a client host is operable to communicate with the configuration entity to obtain information identifying client host specific address ranges to access device resources provisioned to the client host.

14. The system of claim 8, wherein the device is operable to provide information to a host identifying a device resource initiating a transaction.

15. The system of claim 8, wherein a host to which a plurality of device resources are provisioned is operable to access respective resources to respective domains of the client host.

16. The system of claim 8, wherein the device provides, for each device resource, a separate set of resource registers for each host to which a said device resource is provisioned.

17. The system of claim 16, wherein the device is operable to permit access only to a host to which the device resource initiating the transaction is provisioned.

18. The system of claim 8, wherein a device resource is a DMA engine.

19. A method of providing device sharing, the method comprising providing a first plurality of ports as upstream ports, each connectable to a respective host, and providing at least one port as a downstream port connectable to a device, the method further comprising defining a virtual port and associating a routing table with the virtual port to effect device virtualization by redirection of information packets received by the virtual port.