• Opcode is 0x06.
  • The base address of the output (a single page) should be put in the DWORDs 6 and 7 of the command.
  • The low byte of command DWORD 10 indicates what is to be identified: 0 - a namespace, 1 - the controller, 2 - the namespace list.
  • If identifying a namespace, set DWORD 1 to the namespace ID.

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enum {
    NVME_ID_CNS_NS          = 0x00,
    NVME_ID_CNS_CTRL        = 0x01,
    NVME_ID_CNS_NS_ACTIVE_LIST  = 0x02,
    NVME_ID_CNS_NS_DESC_LIST    = 0x03,
    NVME_ID_CNS_CS_NS       = 0x05,
    NVME_ID_CNS_CS_CTRL     = 0x06,
    NVME_ID_CNS_NS_CS_INDEP     = 0x08,
    NVME_ID_CNS_NS_PRESENT_LIST = 0x10,
    NVME_ID_CNS_NS_PRESENT      = 0x11,
    NVME_ID_CNS_CTRL_NS_LIST    = 0x12,
    NVME_ID_CNS_CTRL_LIST       = 0x13,
    NVME_ID_CNS_SCNDRY_CTRL_LIST    = 0x15,
    NVME_ID_CNS_NS_GRANULARITY  = 0x16,
    NVME_ID_CNS_UUID_LIST       = 0x17,
};

CDW1.NSID的含义:

总结:

  1. 想要某个controller或者namespace的identity，需要在command中指定controller id或者namespace id
  2. controller将结果以DMA的形式放到DWORDs 6 and 7指定的地址中

参考资料:

  1. NVMe 1.3 spec
  2. https://wiki.osdev.org/NVMe