---
name: "libnvme_uring_cmd-libnvme3"
section: "2"
platform: "linux"
package: "nvme-cli"
version: "3.2-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/libnvme_uring_cmd-libnvme3"
---

# libnvme\_uring\_cmd-libnvme3(2)

nvme uring command structure

## NAME

struct libnvme\_uring\_cmd - nvme uring command structure

## SYNOPSIS

struct libnvme\_uring\_cmd {\
     **\_\_u8 opcode;**\
     **\_\_u8 flags;**\
     **\_\_u16 rsvd1;**\
     **\_\_u32 nsid;**\
     **\_\_u32 cdw2;**\
     **\_\_u32 cdw3;**\
     **\_\_u64 metadata;**\
     **\_\_u64 addr;**\
     **\_\_u32 metadata\_len;**\
     **\_\_u32 data\_len;**\
     **\_\_u32 cdw10;**\
     **\_\_u32 cdw11;**\
     **\_\_u32 cdw12;**\
     **\_\_u32 cdw13;**\
     **\_\_u32 cdw14;**\
     **\_\_u32 cdw15;**\
     **\_\_u32 timeout\_ms;**\
     **\_\_u32 rsvd2;**\
 };\

## Members

- opcode

  Operation code, see *enum libnvme\_io\_opcodes* and *enum libnvme\_admin\_opcodes*

- flags

  Not supported: intended for command flags (eg: SGL, FUSE)

- rsvd1

  Reserved for future use

- nsid

  Namespace Identifier, or Fabrics type

- cdw2

  Command Dword 2 (no spec defined use)

- cdw3

  Command Dword 3 (no spec defined use)

- metadata

  User space address to metadata buffer (NULL if not used)

- addr

  User space address to data buffer (NULL if not used)

- metadata\_len

  Metadata buffer transfer length

- data\_len

  Data buffer transfer length

- cdw10

  Command Dword 10 (command specific)

- cdw11

  Command Dword 11 (command specific)

- cdw12

  Command Dword 12 (command specific)

- cdw13

  Command Dword 13 (command specific)

- cdw14

  Command Dword 14 (command specific)

- cdw15

  Command Dword 15 (command specific)

- timeout\_ms

  If non-zero, overrides system default timeout in milliseconds

- rsvd2

  Reserved for future use (and fills an implicit struct pad