[PATCH 2/3] nvmet: add ABI documentation for target configfs interfaces
Guixin Liu
kanie at linux.alibaba.com
Wed Jul 1 23:51:23 PDT 2026
在 2026/7/2 14:35, Hannes Reinecke 写道:
> On 7/2/26 5:48 AM, Guixin Liu wrote:
>> Add Documentation/ABI/testing/configfs-nvmet documenting all NVMe
>> target configfs attributes, covering port attributes, subsystem
>> attributes, namespace attributes, host authentication, passthrough
>> mode, and ANA configuration.
>>
>> Each entry has been traced to its original introducing commit to
>> provide accurate Date, KernelVersion, and Contact information.
>>
>> Signed-off-by: Guixin Liu <kanie at linux.alibaba.com>
>> ---
>> Documentation/ABI/testing/configfs-nvmet | 347 +++++++++++++++++++++++
>> 1 file changed, 347 insertions(+)
>> create mode 100644 Documentation/ABI/testing/configfs-nvmet
>>
>> diff --git a/Documentation/ABI/testing/configfs-nvmet
>> b/Documentation/ABI/testing/configfs-nvmet
>> new file mode 100644
>> index 000000000000..728c905310c5
>> --- /dev/null
>> +++ b/Documentation/ABI/testing/configfs-nvmet
>> @@ -0,0 +1,347 @@
>> +What: /config/nvmet/ports/N/addr_adrfam
>> +What: /config/nvmet/ports/N/addr_portid
>> +What: /config/nvmet/ports/N/addr_traddr
>> +What: /config/nvmet/ports/N/addr_trsvcid
>> +What: /config/nvmet/ports/N/addr_trtype
>> +What: /config/nvmet/ports/N/addr_treq
>> +Date: June 2016
>> +KernelVersion: 4.8
>> +Contact: Christoph Hellwig <hch at lst.de>
>> +Description:
>> + Address attributes for an NVMe-oF target port.
>> +
>> + addr_adrfam: Shows or sets the address family. Accepted
>> + values: "pcie", "ipv4", "ipv6", "ib", "fc", "pci", "loop".
>> +
>> + addr_portid: Shows or sets the port identifier (u16).
>> +
>> + addr_traddr: Shows or sets the transport address string.
>> +
>> + addr_trsvcid: Shows or sets the transport service identifier.
>> +
>> + addr_trtype: Shows or sets the transport type. Accepted
>> + values: "rdma", "fc", "tcp", "pci", "loop". Also
>> + initializes default TSAS values.
>> +
>> + addr_treq: Shows or sets the transport security requirements.
>> + Accepted values: "not specified", "required",
>> + "not required". For TCP with TLS1.3, "not specified" is
>> + rejected.
>> +
>> + All attributes require the port to be disabled before
>> + modification.
>> +
>> +What: /config/nvmet/ports/N/referrals/NAME/addr_adrfam
>> +What: /config/nvmet/ports/N/referrals/NAME/addr_portid
>> +What: /config/nvmet/ports/N/referrals/NAME/addr_traddr
>> +What: /config/nvmet/ports/N/referrals/NAME/addr_trsvcid
>> +What: /config/nvmet/ports/N/referrals/NAME/addr_trtype
>> +What: /config/nvmet/ports/N/referrals/NAME/addr_treq
>> +What: /config/nvmet/ports/N/referrals/NAME/enable
>> +Date: June 2016
>> +KernelVersion: 4.8
>> +Contact: Christoph Hellwig <hch at lst.de>
>> +Description:
>> + Address attributes and enable control for a referral entry
>> + under a port. The addr_* attributes have the same semantics
>> + as the corresponding port-level attributes. The enable
>> + attribute shows or sets whether this referral is enabled
>> + (boolean).
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_allow_any_host
>> +Date: June 2016
>> +KernelVersion: 4.8
>> +Contact: Christoph Hellwig <hch at lst.de>
>> +Description:
>> + Shows or sets whether any host is allowed to connect.
>> + Accepts boolean value. Cannot be set to 1 if explicit
>> + hosts are linked in the allowed_hosts/ directory.
>> +
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/device_path
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/device_nguid
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/enable
>> +Date: June 2016
>> +KernelVersion: 4.8
>> +Contact: Christoph Hellwig <hch at lst.de>
>> +Description:
>> + Namespace attributes added with the initial NVMe target.
>> +
>> + device_path: Shows or sets the backend block device path.
>> + The namespace must be disabled before modification.
>> +
>> + device_nguid: Shows or sets the NGUID (128-bit identifier).
>> + Accepts 32 hex digits with optional "-" or ":" separators.
>> + The namespace must be disabled before modification.
>> +
>> + enable: Shows or sets whether this namespace is enabled
>> + (boolean).
>> +
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/device_uuid
>> +Date: June 2017
>> +KernelVersion: 4.13
>> +Contact: Johannes Thumshirn <jthumshirn at suse.de>
>> +Description:
>> + Shows or sets the UUID for this namespace. The namespace
>> + must be disabled before modification.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_version
>> +What: /config/nvmet/subsystems/NAME/attr_serial
>> +Date: July 2017
>> +KernelVersion: 4.13
>> +Contact: Johannes Thumshirn <jthumshirn at suse.de>
>> +Description:
>> + attr_version: Shows or sets the NVMe version reported by
>> + this subsystem. Format: "major.minor" or
>> + "major.minor.tertiary". Cannot be changed after the
>> + subsystem has been discovered.
>> +
>> + attr_serial: Shows or sets the serial number. Must be a
>> + 1-20 byte ASCII string (characters 0x20-0x7e). Cannot be
>> + changed after the subsystem has been discovered.
>> +
>> +What: /config/nvmet/ports/N/ana_groups/ID/ana_state
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/ana_grpid
>> +Date: June 2018
>> +KernelVersion: 4.19
>> +Contact: Christoph Hellwig <hch at lst.de>
>> +Description:
>> + ANA (Asymmetric Namespace Access) attributes.
>> +
>> + ana_state: Shows or sets the ANA state for this group on
>> + this port. Accepted values: "optimized", "non-optimized",
>> + "inaccessible", "persistent-loss", "change". Changes
>> + trigger an ANA change event.
>> +
>> + ana_grpid: Shows or sets the ANA Group ID for this
>> + namespace. Must be between 1 and 128. Changing triggers
>> + an ANA event notification.
>> +
>> +What: /config/nvmet/ports/N/param_inline_data_size
>> +Date: June 2018
>> +KernelVersion: 4.19
>> +Contact: Steve Wise <swise at opengridcomputing.com>
>> +Description:
>> + Shows or sets the inline data size for this port. Default
>> + is -1 which lets the transport choose. The port must be
>> + disabled before modification.
>> +
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/buffered_io
>> +Date: June 2018
>> +KernelVersion: 4.19
>> +Contact: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
>> +Description:
>> + Shows or sets whether buffered I/O is used for this
>> + namespace. Accepts boolean value. The namespace must be
>> + disabled before modification.
>> +
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/p2pmem
>> +Date: October 2018
>> +KernelVersion: 4.20
>> +Contact: Logan Gunthorpe <logang at deltatee.com>
>> +Description:
>> + Shows or sets the P2P DMA memory device for this namespace.
>> + Accepts a PCI device BDF, "auto", or "none". The namespace
>> + must be disabled before modification. Only available when
>> + CONFIG_PCI_P2PDMA is enabled.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_cntlid_min
>> +What: /config/nvmet/subsystems/NAME/attr_cntlid_max
>> +Date: January 2020
>> +KernelVersion: 5.7
>> +Contact: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
>> +Description:
>> + attr_cntlid_min: Shows or sets the minimum controller ID
>> + (u16). Must be nonzero and not greater than attr_cntlid_max.
>> +
>> + attr_cntlid_max: Shows or sets the maximum controller ID
>> + (u16). Must be nonzero and not less than attr_cntlid_min.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_model
>> +Date: January 2020
>> +KernelVersion: 5.7
>> +Contact: Mark Ruijter <MRuijter at onestopsystems.com>
>> +Description:
>> + Shows or sets the model number for this subsystem. Must
>> + be a 1-40 byte ASCII string (characters 0x20-0x7e).
>> + Cannot be changed after the subsystem has been discovered.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_pi_enable
>> +What: /config/nvmet/ports/N/param_pi_enable
>> +Date: May 2020
>> +KernelVersion: 5.8
>> +Contact: Israel Rukshin <israelr at mellanox.com>
>> +Description:
>> + Shows or sets whether protection information (PI) is
>> + enabled/supported. Accepts boolean value. Only available
>> + when CONFIG_BLK_DEV_INTEGRITY is enabled. The port-level
>> + attribute requires the port to be disabled before
>> + modification.
>> +
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/revalidate_size
>> +Date: May 2020
>> +KernelVersion: 5.8
>> +Contact: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
>> +Description:
>> + Write-only. Writing 1 triggers namespace size revalidation.
>> + If the size has changed, a namespace changed AEN is sent.
>> + The namespace must be enabled.
>> +
>> +What: /config/nvmet/subsystems/NAME/passthru/device_path
>> +What: /config/nvmet/subsystems/NAME/passthru/enable
>> +Date: July 2020
>> +KernelVersion: 5.9
>> +Contact: Logan Gunthorpe <logang at deltatee.com>
>> +Description:
>> + Passthrough mode attributes.
>> +
>> + device_path: Shows or sets the NVMe controller character
>> + device path (e.g., /dev/nvme0). Cannot be changed while
>> + the passthrough controller is active.
>> +
>> + enable: Shows or sets whether passthrough mode is enabled
>> + (boolean).
>> +
>> + Only available when CONFIG_NVME_TARGET_PASSTHRU is enabled.
>> +
>> +What: /config/nvmet/subsystems/NAME/passthru/admin_timeout
>> +What: /config/nvmet/subsystems/NAME/passthru/io_timeout
>> +Date: November 2020
>> +KernelVersion: 5.11
>> +Contact: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>
>> +Description:
>> + admin_timeout: Shows or sets the admin command timeout for
>> + passthrough mode, in jiffies.
>> +
>> + io_timeout: Shows or sets the I/O command timeout for
>> + passthrough mode, in jiffies.
>> +
>> + Only available when CONFIG_NVME_TARGET_PASSTHRU is enabled.
>> +
>> +What: /config/nvmet/subsystems/NAME/passthru/clear_ids
>> +Date: June 2022
>> +KernelVersion: 5.19
>> +Contact: Alan Adamson <alan.adamson at oracle.com>
>> +Description:
>> + Shows or sets whether to clear identify data IDs in
>> + passthrough mode. Only available when
>> + CONFIG_NVME_TARGET_PASSTHRU is enabled.
>> +
>> +What: /config/nvmet/hosts/HOSTNQN/dhchap_key
>> +What: /config/nvmet/hosts/HOSTNQN/dhchap_ctrl_key
>> +What: /config/nvmet/hosts/HOSTNQN/dhchap_hash
>> +Date: June 2022
>> +KernelVersion: 6.0
>> +Contact: Hannes Reinecke <hare at suse.de>
>> +Description:
>> + DH-HMAC-CHAP authentication attributes.
>> +
>> + dhchap_key: Shows or sets the host secret key. Accepts a
>> + key string in "DHHC-1:" format.
>> +
>> + dhchap_ctrl_key: Shows or sets the controller secret key
>> + for bidirectional authentication. Same format as dhchap_key.
>> +
>> + dhchap_hash: Shows or sets the HMAC hash algorithm.
>> + Accepted values: "hmac(sha256)", "hmac(sha384)",
>> + "hmac(sha512)".
>> +
>> + Only available when CONFIG_NVME_TARGET_AUTH is enabled.
>> +
>> +What: /config/nvmet/hosts/HOSTNQN/dhchap_dhgroup
>> +Date: June 2022
>> +KernelVersion: 6.0
>> +Contact: Hannes Reinecke <hare at suse.de>
>> +Description:
>> + Shows or sets the Diffie-Hellman group for DH-HMAC-CHAP
>> + key exchange. Accepted values: "null", "ffdhe2048",
>> + "ffdhe3072", "ffdhe4096", "ffdhe6144". Non-null groups
>> + require the corresponding KPP crypto algorithm to be
>> + available. Only available when CONFIG_NVME_TARGET_AUTH
>> + is enabled.
>> +
>
> Why is this a separate entry, and not grouped with the other dhchap
> entries?
>
> And these are 'host' settings. Please keep settings for 'host',
> 'subsystem', and 'ports' together.
>
Changed in v2, thanks.
Best Regards,
Guixin Liu
>> +What: /config/nvmet/subsystems/NAME/attr_qid_max
>> +Date: August 2022
>> +KernelVersion: 6.1
>> +Contact: Daniel Wagner <dwagner at suse.de>
>> +Description:
>> + Shows or sets the maximum queue ID (number of I/O queues,
>> + u16). Must be between 1 and 128. Changing this value
>> + forces reconnection of all connected controllers.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_ieee_oui
>> +Date: November 2022
>> +KernelVersion: 6.2
>> +Contact: Aleksandr Miloserdov <a.miloserdov at yadro.com>
>> +Description:
>> + Shows or sets the IEEE OUI for this subsystem. Displayed
>> + in "0x%06x" format. Must be a 24-bit value. Cannot be
>> + changed after the subsystem has been discovered.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_firmware
>> +Date: November 2022
>> +KernelVersion: 6.2
>> +Contact: Aleksandr Miloserdov <a.miloserdov at yadro.com>
>> +Description:
>> + Shows or sets the firmware revision string for this
>> + subsystem. Must be a 1-8 byte ASCII string (characters
>> + 0x20-0x7e). Cannot be changed after the subsystem has
>> + been discovered.
>> +
>> +What: /config/nvmet/ports/N/addr_tsas
>> +Date: August 2023
>> +KernelVersion: 6.7
>> +Contact: Hannes Reinecke <hare at suse.de>
>> +Description:
>> + Shows or sets the transport-specific address subtype. For
>> + TCP transport, accepted values: "none", "tls1.3" (requires
>> + CONFIG_NVME_TARGET_TCP_TLS). For RDMA transport, shows the
>> + QP type: "connected" or "datagram". The port must be
>> + disabled before modification.
>> +
>> +What: /config/nvmet/ports/N/param_max_queue_size
>> +Date: January 2024
>> +KernelVersion: 6.9
>> +Contact: Max Gurtovoy <mgurtovoy at nvidia.com>
>> +Description:
>> + Shows or sets the maximum queue size for this port. Default
>> + is -1 which lets the transport choose. The port must be
>> + disabled before modification.
>> +
>> +What: /config/nvmet/discovery_nqn
>> +Date: April 2024
>> +KernelVersion: 6.9
>> +Contact: Hannes Reinecke <hare at kernel.org>
>> +Description:
>> + Shows or sets the NQN of the discovery subsystem. The
>> + value must be unique and not duplicate any existing
>> + subsystem name.
>> +
>> +What: /config/nvmet/subsystems/NAME/namespaces/NSID/resv_enable
>> +Date: November 2024
>> +KernelVersion: 6.13
>> +Contact: Guixin Liu <kanie at linux.alibaba.com>
>> +Description:
>> + Shows or sets whether persistent reservation support is
>> + enabled for this namespace. Accepts boolean value. The
>> + namespace must be disabled before modification.
>> +
>> +What: /config/nvmet/subsystems/NAME/attr_vendor_id
>> +What: /config/nvmet/subsystems/NAME/attr_subsys_vendor_id
>> +Date: January 2025
>> +KernelVersion: 6.14
>> +Contact: Damien Le Moal <dlemoal at kernel.org>
>> +Description:
>> + attr_vendor_id: Shows or sets the PCI vendor ID reported
>> + by this subsystem. Displayed in "0x%x" format.
>> +
>> + attr_subsys_vendor_id: Shows or sets the PCI subsystem
>> + vendor ID. Displayed in "0x%x" format.
>> +
>> +What: /config/nvmet/ports/N/param_mdts
>> +Date: April 2026
>> +KernelVersion: 7.1
>> +Contact: Aurelien Aptel <aaptel at nvidia.com>
>> +Description:
>> + Shows or sets the maximum data transfer size for this port.
>> + Default is -1 which lets the transport choose. The port
>> + must be disabled before modification.
>
> Otherwise looks good.
>
> Cheers,
>
> Hannes
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