System and method for implementing logical switches in a network system

In a shared I/O subsystem for a plurality of computer systems, the shared I/O subsystem comprising a plurality of virtual I/O interfaces, a plurality of I/O interfaces, and a forwarding function having a plurality of forwarding table entries, a method comprising:

• communicatively coupling the virtual I/O interfaces to the computer systems, each of the computer systems including a virtual adapter that communicates with one of the virtual I/O interfaces;
• logically arranging, with the forwarding function, the shared I/O subsystem into one or more logical switches, wherein each of the logical switches communicatively couples one or more of the virtual I/O interfaces to one of the I/O interfaces;
• receiving, with at least one of the logical switches, a first I/O packet from one of the virtual I/O interfaces;
• directing the first I/O packet to at least one of the I/O interface and one or more of other ones of the virtual I/O interfaces;
• receiving, with at least one of the logical switches, a second I/O packet from the I/O interface;
• and
• directing the second I/O packet to one or more of the virtual I/O interfaces;
• wherein at least one I/O interface uses a shared physical network interface card (NIC) to couple a plurality of servers to the shared I/O subsystem, each of the plurality of servers having software installed thereon that implements a virtual NIC, wherein the virtual NIC on each given server allows the given server to communicate via the shared physical NIC as if the shared physical NIC was dedicated only to said given server.

In a shared I/O subsystem for a plurality of computer systems, the shared I/O subsystem comprising a plurality of virtual I/O interfaces, a plurality of I/O interfaces, and a forwarding function having a plurality of forwarding table entries, a method comprising:

• means for communicatively coupling the virtual I/O interfaces to the computer systems, each of the computer systems including a virtual adapter that communicates with one of the virtual I/O interfaces;
• means for logically arranging, with the forwarding function, the shared I/O subsystem into one or more logical switches, wherein each of the logical switches communicatively couples one or more of the virtual I/O interfaces to one of the I/O interfaces;
• means for receiving, with at least one of the logical switches, a first I/O packet from one of the virtual I/O interfaces;
• means for directing the first I/O packet to at least one of the I/O interface and one or more of other ones of the virtual I/O interfaces;
• means for receiving, with at least one of the logical switches, a second I/O packet from the I/O interface;
• and
• means for directing the second I/O packet to one or more of the virtual I/O interfaces;
• wherein at least one I/O interface uses a shared physical network interface card (NIC) to couple a plurality of servers to the shared I/O subsystem, each of the plurality of servers having software installed thereon that implements a virtual NIC, wherein the virtual NIC on each given server allows the given server to communicate via the shared physical NIC as if the shared physical NIC was dedicated only to said given server.