Method and apparatus for shared I/O in a load/store fabric
View Patent ↗An apparatus and method is provided for allowing I/O devices to be shared and/or partitioned among a plurality of processing complexes within the load/store fabric of each of the processing complexes without requiring modification to the operating system or driver software of the processing complexes. The apparatus and method includes a switch for selectively coupling each of the processing complexes to one or more shared I/O devices. The apparatus and method further includes placing information within packets transmitted between the switch and the I/O devices to identify which of the processing complexes the packets are associated with. The invention further includes an apparatus and method within the shared I/O devices to allow the shared I/O devices to service each of the processing complexes independently.
1. A shared data storage controller for accessing network data storage from a plurality of operating system domains (OSDs) via a common load/store link, the controller comprising:
a network interface configured to be coupled to a network and communicate with said network using a first protocol;
a bus interface configured to be coupled to the OSDs, wherein in lieu of including a controller within each of the OSDs that is configured to communicate using said first protocol, each of the OSDs are coupled to share the controller in order to communicate via the network using the first protocol;
a plurality of resources for use in processing packets transferred between the OSDs and said network; and
target logic configured to store data that allocates each of said plurality of resources to respective ones of the OSDs.
2. The shared data storage controller as recited in claim 1 wherein the target logic comprises a table that maps an identification of the OSDs to a resource of said plurality of resources.
3. The shared data storage controller as recited in claim 1 wherein the shared data storage controller comprises at least one of the following: a Fibre Channel controller, a serial ATA controller, a SCSI controller, and a Serial Attached SCSI (SAS) controller.
4. The shared data storage controller as recited in claim 1 wherein the first protocol is at least one of the following: an Ethernet protocol, and a Fibre Channel protocol.
5. The shared data storage controller as recited in claim 1 wherein each OSD corresponds to a root complex in a PCI express hierarchy, and wherein said controller corresponds to an endpoint in the PCI express hierarchy.
6. The shared data storage controller as recited in claim 1 wherein the OSDs are configured to convey data according to a PCI Express protocol, and wherein said bus interface is configured to receive a modified form of the data, the modified form of the data comprising a PCI Express packet having been modified to include an OSD identifier.
7. The shared data storage controller as recited in claim 1 wherein a first one of said plurality of resources is allocated to a first one of the plurality of OSD's and a second one of said plurality of resources is allocated to a second one of the plurality of OSD's.
8. The shared data storage controller as recited in claim 1 wherein said plurality of resources comprise a plurality of control registers.