Multi-mode address mapping management

A system, comprising:

• a host;
• storage;
• and
• a storage controller configured to control the storage, the storage controller having one or more processors, one or more computer-readable memories including a cache and nonvolatile storage (NVS) having a plurality of data unit buffers, one or more computer-readable, tangible storage devices, a plurality of adapters coupling the storage controller to a host and to storage;
• a hypervisor configured for address mapping between a selected adapter and a selected memory, and program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more memories, to perform operations, the operations comprising:
• address mapping in a selected address mapping management mode, a selected data unit buffer of the storage controller and a selected adapter coupled to the storage controller, for a first data transfer between an address mapped data unit buffer and an address mapped adapter;
• upon completion of the first data transfer, initiating unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer in the selected address mapping management mode;
• in response to the selected address mapping management mode being in a first address mapping management mode, confirming that the initiated unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer is complete prior to again initiating address mapping a selected data unit buffer of the storage controller and a selected adapter coupled to the storage controller, for a second data transfer between an addressed mapped data unit buffer and an addressed mapped adapter;
• and
• in response to the selected address mapping management mode being in a second address mapping management mode, again initiating address mapping a selected data unit buffer of the storage controller and a selected adapter coupled to the storage controller, for a second data transfer between an address mapped data unit buffer and an addressed mapped adapter, without confirming that the initiated unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer is complete so that confirming that the initiated unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer is complete, is bypassed prior to again initiating address mapping a selected data unit buffer of the storage controller and a selected adapter.

A computer-implemented method, comprising:

• address mapping in a selected address mapping management mode, a selected data unit buffer of a storage controller and a selected adapter coupled to the storage controller, for a first data transfer between an address mapped data unit buffer and an addressed mapped adapter;
• upon completion of the first data transfer, initiating unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer in the selected address mapping management mode;
• in response to the selected address mapping management mode being in a first address mapping management mode, confirming that the initiated unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer is complete prior to again initiating address mapping a selected data unit buffer of the storage controller and a selected adapter coupled to the storage controller, for a second data transfer between an addressed mapped data unit buffer and an addressed mapped adapter;
• and
• in response to the selected address mapping management mode being in a second address mapping management mode, again initiating address mapping a selected data unit buffer of the storage controller and a selected adapter coupled to the storage controller, for a second data transfer between an address mapped data unit buffer and an addressed mapped adapter, without confirming that the initiated unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer is complete so that confirming that the initiated unmapping of the address mapped data unit buffer and the address mapped adapter of the first data transfer is complete, is bypassed prior to again initiating address mapping a selected data unit buffer of the storage controller and a selected adapter.