System and method for discovering and protecting shared allocated resources in a shared virtualized i/o device

A system comprising:

• a virtualized input/output (I/O) device including:
• one or more programmed I/O (PIO) configuration registers corresponding to a plurality of hardware resources;
• and
• a storage configured to store a resource discovery table that includes a plurality of entries, each entry corresponding to a respective hardware resource;
• a system processor coupled to the virtualized I/O device and configured to execute system management instructions to:
• allocate the plurality of hardware resources to a plurality of functions;
• and
• program each entry of the resource discovery table for each function of the plurality of functions with an encoded value that indicates whether a requested hardware resource has been allocated to a requesting process, and whether the requested hardware resource is shared with another function;
• a processing unit coupled to the virtualized I/O device and configured to execute instructions corresponding to one or more processes;
• wherein the processing unit is further configured to execute instructions corresponding to a device driver instance associated with a given process to discover allocated resources by requesting a read access to the resource discovery table of the corresponding function.

A virtualized input/output (I/O) device comprising:

• a host interface;
• a plurality of hardware resources coupled to the host interface;
• a storage coupled to the host interface and configured to store a respective resource discovery table for each function of a plurality of functions;
• wherein each resource discovery table includes a plurality of entries, wherein each entry corresponds to a respective hardware resource of the plurality of hardware resources, wherein each entry includes an encoded value;
• one or more programmed I/O (PIO) configuration registers, each configured to store PIO configuration information corresponding to a respective process executing on a processing unit;
• wherein the host interface is configured to receive from a device driver instance associated with a given process, a PIO request for read access to the resource discovery table of the corresponding function;
• wherein the host interface is further configured to inspect the resource discovery table for the corresponding function to determine whether the requested hardware resource has been allocated to the requesting process, and whether the requested hardware resource is shared with another function based upon the encoded values in the entry corresponding to the requested hardware resource.