Dynamic host memory allocation to a memory controller

An apparatus comprising:

• host memory;
• and
• a host controller having a memory system interface configured communicate with a memory system having a non-volatile memory controller, the host controller configured to:
• during initialization of the non-volatile memory controller, provide the non-volatile memory controller with an amount of the host memory for exclusive use of the non-volatile memory controller;
• access non-volatile memory in the memory system via the memory system interface;
• receive a request from the non-volatile memory controller after the non-volatile memory controller is initialized for a dynamic change in the amount of the host memory that is allocated for exclusive use of the non-volatile memory controller;
• and
• dynamically change the amount of the host memory that is allocated for exclusive use of the non-volatile memory controller in response to the request.

A method of allocating a Non-volatile Memory Express (NVMe) Host Memory Buffer (HMB) in a host system to a Non-volatile Memory Express (NVMe) memory controller, the method comprising:

• receiving a request from the NVMe memory controller for an amount of host memory in the host system as an HMB during an initialization of the NVMe memory controller;
• in response to the request during initialization, providing the NVMe memory controller with an HMB descriptor list having entries that point to regions of the host memory;
• during runtime after the initialization, receiving a request from the NVMe memory controller for additional host memory for the HMB;
• modifying the HMB descriptor list to include one or more entries to the additional host memory for the HMB;
• and
• providing the NVMe memory controller with an indication that the HMB descriptor list has been updated.

A memory system comprising:

• host memory;
• means for initializing a non-volatile memory controller that has direct memory access of the host memory;
• means for providing the non-volatile memory controller with a descriptor list when initializing the non-volatile memory controller, the descriptor list having entries that point to regions of the host memory that are for exclusive use of the non-volatile memory controller;
• means for dynamically updating the descriptor list in response to a runtime request from the non-volatile memory controller for additional host memory, the updated descriptor list having entries that point to regions of the host memory that are for the exclusive use of the non-volatile memory controller;
• and
• means for providing the non-volatile memory controller with an indication that the descriptor list has been updated in response to the runtime request.

A memory system, comprising:

• host memory;
• a communication interface;
• a host controller in communication with the host memory and the communication interface;
• non-volatile memory;
• and
• a memory controller in communication with the non-volatile memory and the communication interface, the memory controller configured to:
• control access over the communication interface of the host controller to the non-volatile memory;
• during an initialization of the memory controller, request the host controller for an amount of the host memory for exclusive use of the memory controller;
• receive descriptors that point to regions of the host memory that are allocated during the initialization for the exclusive use of the memory controller;
• during runtime of the memory controller, request the host controller for a change in the amount of the host memory that is allocated for the exclusive use of the memory controller;
• receive a change to the descriptors that point to regions of the host memory that are allocated for the exclusive use of the memory controller;
• and
• based on the descriptors, directly access a portion of the host memory that is allocated for the exclusive use of the memory controller.