[PATCH v4 1/3] nvme: add ABI documentation for host sysfs interfaces
Guixin Liu <[email protected]>
| Newsgroups | org.infradead.lists.linux-nvme |
|---|---|
| Message-ID | <[email protected]> |
Add Documentation/ABI/stable/sysfs-nvme documenting all NVMe host sysfs attributes, covering controller attributes under /sys/class/nvme/nvmeX/, namespace attributes under /sys/block/nvmeXnY/, and subsystem attributes under /sys/class/nvme-subsystem/nvme-subsysX/. Each entry has been traced to its original introducing commit to provide accurate Date, KernelVersion, and Contact information. Signed-off-by: Guixin Liu <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Reviewed-by: Daniel Wagner <[email protected]> Reviewed-by: Nilay Shroff <[email protected]> --- Documentation/ABI/stable/sysfs-nvme | 453 +++++++++++++++++++++++++++ Documentation/ABI/testing/sysfs-nvme | 13 - 2 files changed, 453 insertions(+), 13 deletions(-) create mode 100644 Documentation/ABI/stable/sysfs-nvme delete mode 100644 Documentation/ABI/testing/sysfs-nvme diff --git a/Documentation/ABI/stable/sysfs-nvme b/Documentation/ABI/stable/sysfs-nvme new file mode 100644 index 000000000000..a2f5d0710db4 --- /dev/null +++ b/Documentation/ABI/stable/sysfs-nvme @@ -0,0 +1,453 @@ +What: /sys/class/nvme/nvmeX/model +What: /sys/class/nvme/nvmeX/serial +What: /sys/class/nvme/nvmeX/firmware_rev +Date: January 2016 +KernelVersion: 4.5 +Contact: Keith Busch <[email protected]> +Description: + Shows the model, serial number, or firmware revision string + of the NVMe controller, as reported in the Identify + Controller data structure. + +What: /sys/class/nvme/nvmeX/cntlid +Date: February 2016 +KernelVersion: 4.6 +Contact: Ming Lin <[email protected]> +Description: + Shows the controller identifier assigned by the NVMe + subsystem. + +What: /sys/class/nvme/nvmeX/cntrltype +What: /sys/class/nvme/nvmeX/dctype +Date: February 2022 +KernelVersion: 5.18 +Contact: Martin Belanger <[email protected]> +Description: + cntrltype: Shows the controller type. Possible values: "io", + "discovery", "admin", "reserved". + + dctype: Shows the discovery controller type. Possible values: + "none", "ddc", "cdc", "reserved". + +What: /sys/class/nvme/nvmeX/reset_controller +Date: November 2015 +KernelVersion: 4.5 +Contact: Christoph Hellwig <[email protected]> +Description: + Write-only. Writing any value triggers a synchronous + controller reset. + +What: /sys/class/nvme/nvmeX/rescan_controller +Date: April 2016 +KernelVersion: 4.7 +Contact: Keith Busch <[email protected]> +Description: + Write-only. Writing any value triggers a namespace rescan + on this controller. + +What: /sys/class/nvme/nvmeX/transport +What: /sys/class/nvme/nvmeX/subsysnqn +What: /sys/class/nvme/nvmeX/address +What: /sys/class/nvme/nvmeX/delete_controller +What: /sys/class/nvme/nvmeX/reconnect_delay +What: /sys/class/nvme/nvmeX/ctrl_loss_tmo +Date: June 2016 +KernelVersion: 4.8 +Contact: Ming Lin <[email protected]> +Description: + Fabrics controller attributes added with NVMe-oF support. + + transport: Shows the transport type string. Possible values: + "pcie", "tcp", "rdma", "fc", "loop". + + subsysnqn: Shows the NVMe Qualified Name (NQN) of the + subsystem this controller belongs to. + + address: Shows the transport-specific address string. Only + available for fabrics controllers. + + delete_controller: Write-only. Triggers deletion of this + fabrics controller. + + reconnect_delay: Shows or sets the reconnect delay in + seconds. Reading returns the delay value, or "off" if + disabled. + + ctrl_loss_tmo: Shows or sets the controller loss timeout in + seconds. Reading returns the timeout value, or "off" if + infinite reconnects are allowed. Writing a negative value + disables the timeout. + +What: /sys/class/nvme/nvmeX/hostnqn +What: /sys/class/nvme/nvmeX/hostid +Date: February 2020 +KernelVersion: 5.7 +Contact: Sagi Grimberg <[email protected]> +Description: + hostnqn: Shows the host NQN used by this fabrics controller. + + hostid: Shows the host identifier (UUID format) used by this + fabrics controller. + + Only available for fabrics controllers. + +What: /sys/class/nvme/nvmeX/fast_io_fail_tmo +Date: November 2020 +KernelVersion: 5.11 +Contact: Victor Gladkov <[email protected]> +Description: + Shows or sets the fast I/O fail timeout in seconds. Reading + returns the timeout value, or "off" if disabled. Writing a + negative value disables the fast I/O fail. Only available + for fabrics controllers. + +What: /sys/class/nvme/nvmeX/kato +Date: April 2021 +KernelVersion: 5.13 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the Keep Alive Timeout value in milliseconds for + this controller. + +What: /sys/class/nvme/nvmeX/cmb +Date: October 2016 +KernelVersion: 4.9 +Contact: Stephen Bates <[email protected]> +Description: + Shows the Controller Memory Buffer (CMB) register values + in format "cmbloc : 0x%08x\ncmbsz : 0x%08x\n". Only + visible when the controller has a CMB (cmbsz != 0). + PCI transport only. + +What: /sys/class/nvme/nvmeX/cmbloc +What: /sys/class/nvme/nvmeX/cmbsz +What: /sys/class/nvme/nvmeX/hmb +Date: July 2021 +KernelVersion: 5.15 +Contact: Keith Busch <[email protected]> +Description: + cmbloc: Shows the CMBLOC register value. + + cmbsz: Shows the CMBSZ register value. + + cmbloc and cmbsz are only visible when the controller has + a CMB. PCI transport only. + + hmb: Shows or sets whether the Host Memory Buffer (HMB) is + enabled. Reading returns 1 (enabled) or 0 (disabled). + Writing 1 enables HMB; writing 0 disables it. Only + visible when the controller supports HMB (hmpre != 0). + PCI transport only. + +What: /sys/class/nvme/nvmeX/state +Date: November 2016 +KernelVersion: 4.11 +Contact: Sagi Grimberg <[email protected]> +Description: + Shows the current state of the controller. Possible values: + "new", "live", "resetting", "connecting", "deleting", + "deleting (no IO)", "dead". + +What: /sys/class/nvme/nvmeX/numa_node +Date: November 2018 +KernelVersion: 5.0 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the NUMA node the controller is attached to. + +What: /sys/class/nvme/nvmeX/queue_count +What: /sys/class/nvme/nvmeX/sqsize +Date: September 2019 +KernelVersion: 5.4 +Contact: James Smart <[email protected]> +Description: + queue_count: Shows the total number of queues (admin + I/O) + for this controller. + + sqsize: Shows the submission queue size for this controller. + +What: /sys/class/nvme/nvmeX/dhchap_secret +What: /sys/class/nvme/nvmeX/dhchap_ctrl_secret +Date: June 2022 +KernelVersion: 6.0 +Contact: Hannes Reinecke <[email protected]> +Description: + dhchap_secret: Shows or sets the host DH-HMAC-CHAP secret + for this controller. Reading returns "none" if not set. + Writing must use the "DHHC-1:" key format and triggers + re-authentication. + + dhchap_ctrl_secret: Shows or sets the controller + DH-HMAC-CHAP secret for bidirectional authentication. + Same format as dhchap_secret. + + Only available when CONFIG_NVME_HOST_AUTH is enabled and + for fabrics controllers. + +What: /sys/class/nvme/nvmeX/tls_key +Date: August 2023 +KernelVersion: 6.7 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the serial of the currently active TLS PSK as hex. + Returns empty if no TLS key is active. Only available for + TCP controllers with TLS or secure concatenation enabled + (CONFIG_NVME_TCP_TLS). + +What: /sys/class/nvme/nvmeX/tls_configured_key +Date: July 2024 +KernelVersion: 6.12 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the serial of the configured TLS key. Writing 0 + triggers a PSK reauthentication (REPLACETLSPSK) with + the target. After reauthentication the returned serial + will be the new key. Only available for TCP controllers + with secure concatenation enabled (CONFIG_NVME_TCP_TLS). + +What: /sys/class/nvme/nvmeX/tls_keyring +Date: July 2024 +KernelVersion: 6.12 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the TLS keyring description. Only available for TCP + controllers with a keyring configured (CONFIG_NVME_TCP_TLS). + +What: /sys/class/nvme/nvmeX/tls_mode +Date: April 2026 +KernelVersion: 7.1 +Contact: Daniel Wagner <[email protected]> +Description: + Shows the TLS mode: "tls" for direct TLS or "concat" for + secure concatenation. Only available for TCP controllers + with TLS or secure concatenation enabled + (CONFIG_NVME_TCP_TLS). + +What: /sys/class/nvme/nvmeX/passthru_err_log_enabled +Date: January 2024 +KernelVersion: 6.8 +Contact: Alan Adamson <[email protected]> +Description: + Shows or sets whether admin passthrough error logging is + enabled for this controller. Reading returns "on" or "off". + Writing accepts a boolean value. + +What: /sys/class/nvme/nvmeX/quirks +Date: November 2025 +KernelVersion: 7.0 +Contact: Maurizio Lombardi <[email protected]> +Description: + Shows the active quirk names for this controller, one per + line. Shows "none" if no quirks are active. + +What: /sys/class/nvme/nvmeX/admin_timeout +What: /sys/class/nvme/nvmeX/io_timeout +Date: May 2026 +KernelVersion: 7.2 +Contact: Maurizio Lombardi <[email protected]> +Description: + admin_timeout: Shows or sets the admin command timeout in + milliseconds. + + io_timeout: Shows or sets the I/O command timeout in + milliseconds. Changes are propagated to all namespace + request queues. + + The value must be nonzero. Only writable after the + controller has been started at least once. + +What: /sys/block/nvmeXnY/uuid +What: /sys/block/nvmeXnY/eui +What: /sys/block/nvmeXnY/nsid +Date: December 2015 +KernelVersion: 4.5 +Contact: Keith Busch <[email protected]> +Description: + Namespace identification attributes. + + uuid: Shows the UUID for this namespace. Falls back to + showing the NGUID for backward compatibility. Hidden if + both are all zeros. + + eui: Shows the IEEE Extended Unique Identifier (EUI-64). + Hidden if all zeros. + + nsid: Shows the namespace identifier (NSID). + +What: /sys/block/nvmeXnY/wwid +Date: February 2016 +KernelVersion: 4.6 +Contact: Keith Busch <[email protected]> +Description: + Shows the World Wide Identifier for this namespace. The + format depends on available identifiers (in priority + order): "uuid.{UUID}", "eui.{NGUID}", "eui.{EUI64}", or + "nvme.{VID}-{SERIAL}-{MODEL}-{NSID}". + +What: /sys/block/nvmeXnY/nguid +Date: June 2017 +KernelVersion: 4.13 +Contact: Johannes Thumshirn <[email protected]> +Description: + Shows the Namespace Globally Unique Identifier (NGUID). + Hidden if the NGUID is all zeros. + +What: /sys/block/nvmeXcYnZ/ana_grpid +What: /sys/block/nvmeXcYnZ/ana_state +Date: May 2018 +KernelVersion: 4.19 +Contact: Christoph Hellwig <[email protected]> +Description: + ana_grpid: Shows the ANA Group ID for this namespace + path device. + + ana_state: Shows the ANA state. Possible values: + "optimized", "non-optimized", "inaccessible", + "persistent-loss", "change". + + Only visible when the controller supports ANA. + Requires CONFIG_NVME_MULTIPATH. + +What: /sys/block/nvmeXcYnZ/queue_depth +Date: June 2024 +KernelVersion: 6.11 +Contact: Thomas Song <[email protected]> +Description: + Shows the current active I/O count on this path's + controller. Returns empty if iopolicy is not "queue-depth". + Requires CONFIG_NVME_MULTIPATH. + +What: /sys/block/nvmeXcYnZ/numa_nodes +Date: January 2025 +KernelVersion: 6.15 +Contact: Nilay Shroff <[email protected]> +Description: + Shows the NUMA node mask for which this path is the + currently selected path. Returns empty if iopolicy is not + "numa". Requires CONFIG_NVME_MULTIPATH. + +What: /sys/block/nvmeXnY/delayed_removal_secs +Date: May 2025 +KernelVersion: 6.16 +Contact: Nilay Shroff <[email protected]> +Description: + Shows or sets the delayed removal timeout in seconds for + the multipath head device. When nonzero, I/O is queued + instead of failed when all paths are gone, and head removal + is deferred. Only visible on multipath head devices. + Requires CONFIG_NVME_MULTIPATH. + +What: /sys/block/nvmeXnY/csi +What: /sys/block/nvmeXnY/metadata_bytes +What: /sys/block/nvmeXnY/nuse +Date: December 2023 +KernelVersion: 6.8 +Contact: Daniel Wagner <[email protected]> +Description: + csi: Shows the Command Set Identifier for this namespace. + + metadata_bytes: Shows the metadata size in bytes. + + nuse: Shows the Namespace Utilization (NUSE) value. Reading + triggers an Identify Namespace command to refresh the + value (rate-limited to avoid excessive commands). + +What: /sys/block/nvmeXnY/passthru_err_log_enabled +Date: January 2024 +KernelVersion: 6.8 +Contact: Alan Adamson <[email protected]> +Description: + Shows or sets whether I/O passthrough error logging is + enabled for this namespace. Reading returns "on" or "off". + Writing accepts a boolean value. + +What: /sys/class/nvme/nvmeX/diag/command_error_count +What: /sys/class/nvme/nvmeX/diag/reset_count +What: /sys/class/nvme/nvmeX/diag/reconnect_count +Date: May 2026 +KernelVersion: 7.2 +Contact: Nilay Shroff <[email protected]> +Description: + Controller diagnostic counters. + + command_error_count: Admin command error counter. + + reset_count: Controller reset counter. + + reconnect_count: Accumulated reconnect counter. Only + available for fabrics controllers. + + All counters can be reset by writing a value. + +What: /sys/block/nvmeXnY/diag/command_retries_count +What: /sys/block/nvmeXnY/diag/command_error_count +Date: May 2026 +KernelVersion: 7.2 +Contact: Nilay Shroff <[email protected]> +Description: + Namespace diagnostic counters for non-multipath + configurations (when CONFIG_NVME_MULTIPATH is not + configured). + + command_retries_count: I/O command retry counter. + + command_error_count: I/O command error counter. + + All counters can be reset by writing any value. + +What: /sys/block/nvmeXcYnZ/diag/command_retries_count +What: /sys/block/nvmeXcYnZ/diag/command_error_count +What: /sys/block/nvmeXcYnZ/diag/multipath_failover_count +What: /sys/block/nvmeXnY/diag/io_requeue_no_usable_path_count +What: /sys/block/nvmeXnY/diag/io_fail_no_available_path_count +Date: May 2026 +KernelVersion: 7.2 +Contact: Nilay Shroff <[email protected]> +Description: + Namespace diagnostic counters for multipath + configurations (when CONFIG_NVME_MULTIPATH is + configured). + + command_retries_count: I/O command retry counter. + + command_error_count: I/O command error counter. + + multipath_failover_count: Multipath failover counter. + + io_requeue_no_usable_path_count: Counter of I/Os + requeued because no usable path was available. + + io_fail_no_available_path_count: Counter of I/Os + failed because no available path existed. + + All counters can be reset by writing any value. + +What: /sys/class/nvme-subsystem/nvme-subsysX/model +What: /sys/class/nvme-subsystem/nvme-subsysX/serial +What: /sys/class/nvme-subsystem/nvme-subsysX/firmware_rev +What: /sys/class/nvme-subsystem/nvme-subsysX/subsysnqn +Date: November 2017 +KernelVersion: 4.15 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the model, serial number, firmware revision, or NQN + of the NVMe subsystem. + +What: /sys/class/nvme-subsystem/nvme-subsysX/iopolicy +Date: February 2019 +KernelVersion: 5.1 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows or sets the multipath I/O path selection policy for + this subsystem. Accepted values: "numa", "round-robin", + "queue-depth". Changing the policy clears all current path + selections. Only available when CONFIG_NVME_MULTIPATH is + enabled. + +What: /sys/class/nvme-subsystem/nvme-subsysX/subsystype +Date: September 2021 +KernelVersion: 5.16 +Contact: Hannes Reinecke <[email protected]> +Description: + Shows the subsystem type. Possible values: "discovery", + "nvm", "reserved". diff --git a/Documentation/ABI/testing/sysfs-nvme b/Documentation/ABI/testing/sysfs-nvme deleted file mode 100644 index 499d5f843cd4..000000000000 --- a/Documentation/ABI/testing/sysfs-nvme +++ /dev/null @@ -1,13 +0,0 @@ -What: /sys/devices/virtual/nvme-fabrics/ctl/.../tls_configured_key -Date: November 2025 -KernelVersion: 6.19 -Contact: Linux NVMe mailing list <[email protected]> -Description: - The file is avaliable when using a secure concatanation - connection to a NVMe target. Reading the file will return - the serial of the currently negotiated key. - - Writing 0 to the file will trigger a PSK reauthentication - (REPLACETLSPSK) with the target. After a reauthentication - the value returned by tls_configured_key will be the new - serial. -- 2.43.7