User mode direct data access to non-volatile memory express device via kernel-managed queue pair

A method, implemented by a user mode component, in a computer system that includes a processor system, comprising:

• identifying a mapping of a Non-Volatile Memory Express (NVMe) queue pair, into a user mode address space, the NVMe queue pair comprising a submission queue (SQ) and a completion queue (CQ), and the NVMe queue pair having been mapped into the user mode address space by a kernel mode NVMe driver;
• submitting an NVMe command to an NVMe device, including,
• writing an SQ entry to the SQ of the NVMe queue pair;
• and
• ringing an SQ doorbell register via a system call to the kernel mode NVMe driver, wherein, based on receiving the system call from the user mode component, the kernel mode NVMe driver validates that the user mode component is accessing a valid range of logical block addresses at the NVMe device;
• and
• polling the CQ of the NVMe queue pair and, based on the polling, identifying a CQ entry.

A computer system, comprising:

• a processor system;
• and
• a computer storage medium that stores computer-executable instructions that are executable by the processor system to at least:
• within a kernel mode context in the computer system:
• map a memory buffer into a user mode address space, the memory buffer enabling data transfer with a Non-Volatile Memory Express (NVMe) device via direct memory access (DMA);
• map a first NVMe queue pair, which comprises a first submission queue (SQ) and a first completion queue (CQ), into the user mode address space, the first NVMe queue pair enabling a user mode component to submit a command to the NVMe device;
• enable the user mode component to ring a doorbell at the NVMe device, including exposing a system call to the user mode component;
• and
• based on receiving the system call from the user mode component,
• validate that the user mode component is accessing a valid range of logical block addresses at the NVMe device;
• and
• process a first NVMe command using a second NVMe queue pair, which comprises a second SQ and a second CQ;
• and
• within a user mode context in the computer system:
• identify the first NVMe queue pair;
• submit a second NVMe command to the NVMe device, including,
• writing an SQ entry to the first SQ;
• and
• ringing an SQ doorbell register via the system call;
• and
• poll the first CQ, and, based on the polling, identify a CQ entry.