Abstract: Command trapping in an input/output virtualization (IOV) host controller (HC) (IOV-HC) of a flash-memory-based storage device is disclosed. In one aspect, an IOV-HC is configured to receive a request from a client register interface (CRI) of one of multiple input/output (I/O) clients. The IOV-HC inspects a content of the request prior to the request being passed to a transport protocol engine. Based on the content, the IOV-HC determines whether the request should be further processed or should be trapped. If the IOV-HC determines that the request should be trapped, the IOV-HC traps the request using a request trap. In some aspects, the IOV-HC generates an interrupt to a virtual machine manager (VMM) to notify the VMM that the request was trapped. In some aspects, the IOV-HC provides a response generation circuit to receive instructions from the VMM to generate a response to the CRI from which the trapped request originated.

Abstract: A method for error detection and recovery is provided in which a host controller and host software collaborate together. The host controller may: detect an error condition, set an error interrupt or register, and/or halt task execution or processing at the host controller. The host software may: detect an error condition as a result of the host controller having set the error interrupt or register; performs error handling, and clears the error condition. The host controller then resumes execution or processing of tasks upon detecting that error condition has been cleared by the host software.

Abstract: Ascertaining command completion in flash memories is disclosed. An exemplary aspect includes eliminating the software lock and the outstanding requests variable and replacing them with a transfer request completion register. The transfer request completion register may be mapped to the universal flash storage (UFS) Transfer Protocol (UTP) Transfer Request List (UTRL) slots. The controller of the host—a hardware component—may set the bit in the transfer request completion register on transfer request completion at the same time the doorbell register is cleared. After this bit has been read, the bit in the transfer request completion register is cleared.

Abstract: Command trapping in an input/output virtualization (IOV) host controller (HC) (IOV-HC) of a flash-memory-based storage device is disclosed. In one aspect, an IOV-HC is configured to receive a request from a client register interface (CRI) of one of multiple input/output (I/O) clients. The IOV-HC inspects a content of the request prior to the request being passed to a transport protocol engine. Based on the content, the IOV-HC determines whether the request should be further processed or should be trapped. If the IOV-HC determines that the request should be trapped, the IOV-HC traps the request using a request trap. In some aspects, the IOV-HC generates an interrupt to a virtual machine manager (VMM) to notify the VMM that the request was trapped. In some aspects, the IOV-HC provides a response generation circuit to receive instructions from the VMM to generate a response to the CRI from which the trapped request originated.

Abstract: Ascertaining command completion in flash memories is disclosed. An exemplary aspect includes eliminating the software lock and the outstanding requests variable and replacing them with a transfer request completion register. The transfer request completion register may be mapped to the universal flash storage (UFS) Transfer Protocol (UTP) Transfer Request List (UTRL) slots. The controller of the host—a hardware component—may set the bit in the transfer request completion register on transfer request completion at the same time the doorbell register is cleared. After this bit has been read, the bit in the transfer request completion register is cleared.

Abstract: A method for error detection and recovery is provided in which a host controller and host software collaborate together. The host controller may: detect an error condition, set an error interrupt or register, and/or halt task execution or processing at the host controller. The host software may: detect an error condition as a result of the host controller having set the error interrupt or register; performs error handling, and clears the error condition. The host controller then resumes execution or processing of tasks upon detecting that error condition has been cleared by the host software.

Abstract: A host controller is provided that unilaterally supports queue barrier functionality. The host controller may receive a first task marked with a queue barrier indicator. As a result, the host controller stalls transmission of the first task to a target device. Additionally, the host controller also stalls transmission of any task, occurring after the first task, to the target device. The host controller only sends the first task to the target device once an indication is received from the target device that all previously sent tasks have been processed. The host controller only sends any task, occurring after the first task, to the target device once an indication is received from the target device that the first task has been processed.