Device sharing

• US 20060242352A1
• Filed: 12/01/2005
• Published: 10/26/2006
• Est. Priority Date: 04/22/2005
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Oracle America, Inc. (Oracle Corporation)
• Inventors: Torudbakken, Ola, Johnsen, Bjorn Dag
• Granted Patent: US 7,613,864 B2
• Time in Patent Office: Days
• US Class Current: 710/312
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence

Abstract

An interconnect apparatus, for example a switch, supports PCI-Express. The apparatus has 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 is operable to support sharing of the device resources between hosts.

Claims

1. An 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 configure a downstream port for device virtualization to support sharing of the device between the hosts.

2. The apparatus of claim 1, comprising a configuration entity operable to provision resources of said device to said hosts.

3. The apparatus of claim 1, wherein the downstream port is configured as a shared port connectable to each of a plurality of virtual switches, each virtual switch comprising an upstream port connectable to a respective host.

4. The apparatus of claim 3, operable to associate a routing table with the shared downstream port to virtualize the routing of information packets received by the shared port.

5. The apparatus of claim 1, comprising a downstream port for linking the device with a first upstream port for connection to a host and operable to provide at least one virtual downstream port for linking at least device resource to at least one further upstream port for connection to a host, the virtual downstream port being linked to at least one upstream port via a virtual bus fabric.

6. The apparatus of claim 5, wherein each virtual downstream port is operable to present a device resource provided by the device to a host as if the host had sole ownership of the device.

7. The apparatus of claim 1, wherein a separate address range is associated with each resource of said device.

8. The apparatus of claim 1, wherein the apparatus is an interconnect apparatus.

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

10. A computer system comprising a plurality of hosts, a device shared between the hosts and an interconnect for supporting PCI-Express, the apparatus comprising a first plurality of ports configured as upstream ports, each connected to a respective host, and at least one port configured as a downstream port connected to a device, the apparatus being operable to configure a downstream port for device virtualization to support sharing of the device between the hosts.

11. The system of claim 10 wherein one of said hosts comprises a configuration entity operable to provision resources of said device to said hosts, the host of which the configuration entity forms part forming a master host that has access to all devices in a device tree, wherein any host that is not a master host forms a client host.

12. The system of claim 10, wherein each host is operable to discover device resources provisioned to it using configuration requests.

13. The system of claim 10, wherein a host is operable to observe information for a resource register for a device resource provisioned to that host and to assign an address range to that resource register.

14. The system of claim 10 comprising a plurality of device resources, 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.

15. The system of claim 10, wherein the device is operable to permit access only to a host to which the device resource initiating the transaction is provisioned.

16. The system of claim 10, wherein the device is an I/O device.

17. The system of claim 10, wherein a device resource is a DMA engine.

18. A system supporting a PCI-Express protocol with device sharing between a plurality of hosts, wherein one host is operable to act as a master host with respect to the device and at least another host is operable to act as a client host with respect to the device, the master host being operable to control a shared device and to provision at least one resource of the device to the client host, the client host being operable to influence the operation of the provisioned resource of the device.

19. A method of providing device sharing in a computer system comprising a plurality of hosts, using an interconnect apparatus for supporting PCI-Express, the method comprising:

a. configuring as an upstream port each of a first plurality of ports that are each connected to a respective host;

b. configuring as a downstream port at least one port connected to a device; and

c. configuring the downstream port for device virtualization to support sharing of the device between the hosts.

20. A method of implementing a PCI-Express protocol with device sharing between a plurality of hosts, the method comprising:

a. a one host acting as a master host with respect to the device to control a shared device and at least another host acting as a client host with respect to the device;

b. the master host provisioning at least one resource of the device to the client host; and

c. the client host influencing the operation of the provisioned resource of the device.