mi.h - NVMe Management Interface library (libnvme-mi) definitions.

These provide an abstraction for the MI messaging between controllers and a host, typically over an MCTP-over-i2c link to a NVMe device, used as part of the out-of-band management of a system.

We have a few data structures define here to reflect the topology of a MI connection with an NVMe subsystem:

• libnvme_mi_ep_t: an MI endpoint - our mechanism of communication with a NVMe subsystem. For MCTP, an endpoint will be the component that holds the MCTP address (EID), and receives our request message.

  endpoints are defined in the NVMe-MI spec, and are specific to the MI interface.

  Each endpoint will provide access to one or more of:

• libnvme_mi_ctrl_t: a NVMe controller, as defined by the NVMe base spec. The controllers are responsible for processing any NVMe standard commands (eg, the Admin command set). An endpoint (libnvme_mi_ep_t) may provide access to multiple controllers - so each of the controller- type commands will require a libnvme_mi_ctrl_t to be specified, rather than an endpoint

A couple of conventions with the libnvme-mi API:

• All types and functions have the libnvme_mi prefix, to distinguish from the libnvme core.

• We currently support either MI commands and Admin commands. The former adds a _mi prefix, the latter an _admin prefix. [This does result in the MI functions having a double _mi, like libnvme_mi_mi_subsystem_health_status_poll, which is apparently amusing for our German-speaking readers]

For return values: unless specified in the per-function documentation, all functions:

• return 0 on success

• return -1, with errno set, for errors communicating with the MI device, either in request or response data

• return >1 on MI status errors. This value is the 8-bit MI status value, represented by enum nvme_mi_resp_status. Note that the status values may be vendor-defined above 0xe0.

For the second case, we have a few conventions for errno values:

• EPROTO: response data violated the MI protocol, and libnvme cannot validly interpret the response

• EIO: Other I/O error communicating with device (eg., valid but unexpected response data)

• EINVAL: invalid input arguments for a command

In line with the core NVMe API, the Admin command functions take an _args structure to provide the command-specific parameters. However, for the MI interface, the fd and timeout members of these _args structs are ignored.

References to the specifications here will either to be the NVM Express Management Interface (“NVMe-MI”) or the NVM Express Base specification (“NVMe”). At the time of writing, the versions we’re referencing here are:

• NVMe-MI 1.2b

• NVMe 2.0b

with a couple of accommodations for older spec types, particularly NVMe-MI 1.1, where possible.

const char *libnvme_mi_status_to_string(int status)

return a string representation of the MI status.

Parameters

int status

MI response status

Description

Gives a string description of status, as per section 4.1.2 of the NVMe-MI spec. The status value should be of type NVME_STATUS_MI, and extracted from the return value using nvme_status_get_value().

Returned string is const, and should not be free()ed.

Return

A string representing the status value

type libnvme_mi_ep_t

MI Endpoint object.

Description

Represents our communication endpoint on the remote MI-capable device. To be used for direct MI commands for the endpoint (through the libnvme_mi_mi_* functions(), or to communicate with individual controllers (see libnvme_mi_init_ctrl).

Endpoints are created through a transport-specific constructor; currently only MCTP-connected endpoints are supported, through libnvme_mi_open_mctp. Subsequent operations on the endpoint (and related controllers) are transport-independent.

int libnvme_mi_set_csi(libnvme_mi_ep_t ep, uint8_t csi)

Assign a CSI to an endpoint.

Parameters

libnvme_mi_ep_t ep

Endpoint

uint8_t csi

value to use for CSI bit in NMP (0 or 1) for this endpoint

Return

0 if successful, -1 otherwise (some endpoints may not support)

libnvme_mi_ep_t libnvme_mi_first_endpoint(struct libnvme_global_ctx *ctx)

Start endpoint iterator

Parameters

struct libnvme_global_ctx *ctx

struct libnvme_global_ctx object

Return

first MI endpoint object under this root, or NULL if no endpoints

are present.

Description

See: libnvme_mi_next_endpoint, libnvme_mi_for_each_endpoint

libnvme_mi_ep_t libnvme_mi_next_endpoint(struct libnvme_global_ctx *ctx, libnvme_mi_ep_t e)

Continue endpoint iterator

Parameters

struct libnvme_global_ctx *ctx

struct libnvme_global_ctx object

libnvme_mi_ep_t e

libnvme_mi_ep_t current position of iterator

Return

next endpoint MI endpoint object after e under this root, or NULL

if no further endpoints are present.

Description

See: libnvme_mi_first_endpoint, libnvme_mi_for_each_endpoint

libnvme_mi_for_each_endpoint

libnvme_mi_for_each_endpoint (c, e)

Iterator for NVMe-MI endpoints.

Parameters

c

struct libnvme_global_ctx object

e

libnvme_mi_ep_t object, set on each iteration

libnvme_mi_for_each_endpoint_safe

libnvme_mi_for_each_endpoint_safe (c, e, _e)

Iterator for NVMe-MI endpoints, allowing deletion during traversal

Parameters

c

struct libnvme_global_ctx object

e

libnvme_mi_ep_t object, set on each iteration

_e

libnvme_mi_ep_t object used as temporary storage

int libnvme_mi_ep_set_timeout(libnvme_mi_ep_t ep, unsigned int timeout_ms)

set a timeout for NVMe-MI responses

Parameters

libnvme_mi_ep_t ep

MI endpoint object

unsigned int timeout_ms

Timeout for MI responses, given in milliseconds

void libnvme_mi_ep_set_mprt_max(libnvme_mi_ep_t ep, unsigned int mprt_max_ms)

set the maximum wait time for a More Processing Required response

Parameters

libnvme_mi_ep_t ep

MI endpoint object

unsigned int mprt_max_ms

Maximum more processing required wait time

Description

NVMe-MI endpoints may respond to a request with a “More Processing Required” response; this also includes a hint on the worst-case processing time for the eventual response data, with a specification-defined maximum of 65.535 seconds.

This function provides a way to limit the maximum time we’re prepared to wait for the final response. Specify zero in mprt_max_ms for no limit. This should be larger than the command/response timeout set in :c:type:`libnvme_mi_ep_set_timeout`().

unsigned int libnvme_mi_ep_get_timeout(libnvme_mi_ep_t ep)

get the current timeout value for NVMe-MI responses

Parameters

libnvme_mi_ep_t ep

MI endpoint object

Description

Returns the current timeout value, in milliseconds, for this endpoint.

struct libnvme_transport_handle *libnvme_mi_first_transport_handle(libnvme_mi_ep_t ep)

Start transport handle iterator

Parameters

libnvme_mi_ep_t ep

libnvme_mi_ep_t object

Return

first transport handle to a MI controller object under this

root, or NULL if no controllers are present.

Description

See: libnvme_mi_next_transport_handle, libnvme_mi_for_each_transport_handle

struct libnvme_transport_handle *libnvme_mi_next_transport_handle(libnvme_mi_ep_t ep, struct libnvme_transport_handle *hdl)

Continue transport handle iterator

Parameters

libnvme_mi_ep_t ep

libnvme_mi_ep_t object

struct libnvme_transport_handle *hdl

nvme_transport_handle current position of iterator

Return

next transport handle to MI controller object after c under

this endpoint, or NULL if no further controllers are present.

Description

See: libnvme_mi_first_transport_handle, libnvme_mi_for_each_transport_handle

libnvme_mi_for_each_transport_handle

libnvme_mi_for_each_transport_handle (ep, hdl)

Iterator for transport handle to NVMe-MI controllers.

Parameters

ep

libnvme_mi_ep_t containing endpoints

hdl

nvme_trasnport_handle object, set on each iteration

Description

Allows iteration of the list of controllers behind an endpoint. Unless the controllers have already been created explicitly, you’ll probably want to call :c:type:`libnvme_mi_scan_ep`() to scan for the controllers first.

See: :c:type:`libnvme_mi_scan_ep`()

libnvme_mi_for_each_transport_handle_safe

libnvme_mi_for_each_transport_handle_safe (ep, hdl, _hdl)

Iterator for transport handle to NVMe-MI controllers, allowing deletion during traversal

Parameters

ep

libnvme_mi_ep_t containing controllers

hdl

nvme_transport_handle object, set on each iteration

_hdl

nvme_transport_handle object used as temporary storage

Description

Allows iteration of the list of controllers behind an endpoint, safe against deletion during iteration. Unless the controllers have already been created explicitly (or you’re just iterating to destroy controllers) you’ll probably want to call :c:type:`libnvme_mi_scan_ep`() to scan for the controllers first.

See: :c:type:`libnvme_mi_scan_ep`()

libnvme_mi_ep_t libnvme_mi_open_mctp(struct libnvme_global_ctx *ctx, unsigned int netid, uint8_t eid)

Create an endpoint using a MCTP connection.

Parameters

struct libnvme_global_ctx *ctx

struct libnvme_global_ctx object

unsigned int netid

MCTP network ID on this system

uint8_t eid

MCTP endpoint ID

Description

Transport-specific endpoint initialization for MI-connected endpoints. Once an endpoint is created, the rest of the API is transport-independent.

See libnvme_mi_close

Return

New endpoint object for netid & eid, or NULL on failure.

int libnvme_mi_aem_open(libnvme_mi_ep_t ep)

Prepare an existing endpoint to receive AEMs

Parameters

libnvme_mi_ep_t ep

Endpoint to configure for AEMs

Return

0 if success, -1 otherwise

void libnvme_mi_close(libnvme_mi_ep_t ep)

Close an endpoint connection and release resources, including controller objects.

Parameters

libnvme_mi_ep_t ep

Endpoint object to close

struct libnvme_global_ctx *libnvme_mi_scan_mctp(void)

look for MCTP-connected NVMe-MI endpoints.

Parameters

void

no arguments

Description

This function queries the system MCTP daemon (“mctpd”) over D-Bus, to find MCTP endpoints that report support for NVMe-MI over MCTP.

This requires libvnme-mi to be compiled with D-Bus support; if not, this will return NULL.

Return

A struct libnvme_global_ctx populated with a set of

MCTP-connected endpoints, or NULL on failure

int libnvme_mi_scan_ep(libnvme_mi_ep_t ep, bool force_rescan)

query an endpoint for its NVMe controllers.

Parameters

libnvme_mi_ep_t ep

Endpoint to scan

bool force_rescan

close existing controllers and rescan

Description

This function queries an MI endpoint for the controllers available, by performing an MI Read MI Data Structure command (requesting the controller list). The controllers are stored in the endpoint’s internal list, and can be iterated with libnvme_mi_for_each_ctrl.

This will only scan the endpoint once, unless force_rescan is set. If so, all existing controller objects will be freed - the caller must not hold a reference to those across this call.

See: libnvme_mi_for_each_ctrl

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

struct libnvme_transport_handle *libnvme_mi_init_transport_handle(libnvme_mi_ep_t ep, __u16 ctrl_id)

initialise a transport handle to NVMe controller.

Parameters

libnvme_mi_ep_t ep

Endpoint to create under

__u16 ctrl_id

ID of controller to initialize.

Description

Create a connection to a controller behind the endpoint specified in ep. Controller IDs may be queried from the endpoint through libnvme_mi_mi_read_mi_data_ctrl_list.

See libnvme_mi_close_transport_handle

Return

New transport handle object, or NULL on failure.

__u16 libnvme_mi_ctrl_id(struct libnvme_transport_handle *hdl)

get the ID of a controller

Parameters

struct libnvme_transport_handle *hdl

transport handle to controller to query

Description

Retrieve the ID of the controller, as defined by hardware, and available in the Identify (Controller List) data. This is the value passed to libnvme_mi_init_transport_handle, but may have been created internally via libnvme_mi_scan_ep.

Return

the (locally-stored) ID of this controller.

char *libnvme_mi_endpoint_desc(libnvme_mi_ep_t ep)

Get a string describing a MI endpoint.

Parameters

libnvme_mi_ep_t ep

endpoint to describe

Description

Generates a human-readable string describing the endpoint, with possibly transport-specific data. The string is allocated during the call, and the caller is responsible for free()-ing the string.

Return

a newly-allocated string containing the endpoint description, or

NULL on failure.

void libnvme_mi_ep_set_submit_entry(libnvme_mi_ep_t ep, void *(*mi_submit_entry)(struct libnvme_mi_ep *ep, __u8 type, const struct nvme_mi_msg_hdr *hdr, size_t hdr_len, const void *data, size_t data_len))

Install MI submit-entry callback

Parameters

libnvme_mi_ep_t ep

endpoint to configure

void *(*mi_submit_entry)(struct libnvme_mi_ep *ep, __u8 type, const struct nvme_mi_msg_hdr *hdr, size_t hdr_len, const void *data, size_t data_len)

After input validation the callback is invoked before an MI command is submitted. The function receives the endpoint, message type, header, and data about to be sent, and may return an opaque pointer representing per-command context. This pointer is later passed unmodified to the mi_submit_exit callback. Implementations typically use this hook for logging, tracing, or allocating per-command state.

Description

Installs a callback invoked at the moment an MI command enters the submission path. This applies to all MI operations through this endpoint (both endpoint- level MI commands and controller admin commands). Passing NULL removes any previously installed callback.

void libnvme_mi_ep_set_submit_exit(libnvme_mi_ep_t ep, void (*mi_submit_exit)(struct libnvme_mi_ep *ep, __u8 type, const struct nvme_mi_msg_hdr *hdr, size_t hdr_len, const void *data, size_t data_len, void *user_data))

Install MI submit-exit callback

Parameters

libnvme_mi_ep_t ep

endpoint to configure

void (*mi_submit_exit)(struct libnvme_mi_ep *ep, __u8 type, const struct nvme_mi_msg_hdr *hdr, size_t hdr_len, const void *data, size_t data_len, void *user_data)

Callback invoked after an MI command completes callback (i.e., after a response has been received and passed basic validation). The function receives the endpoint, message type, header, data, and the user_data pointer returned earlier by the mi_submit_entry callback. Implementations typically use this hook for logging, tracing, or freeing per-command state.

Description

Installs a callback invoked when an MI command completes. This applies to all MI operations through this endpoint. Passing NULL removes any previously installed callback.

int libnvme_mi_mi_xfer(libnvme_mi_ep_t ep, struct nvme_mi_mi_req_hdr *mi_req, size_t req_data_size, struct nvme_mi_mi_resp_hdr *mi_resp, size_t *resp_data_size)

Raw mi transfer interface.

Parameters

libnvme_mi_ep_t ep

endpoint to send the MI command to

struct nvme_mi_mi_req_hdr *mi_req

request data

size_t req_data_size

size of request data payload

struct nvme_mi_mi_resp_hdr *mi_resp

buffer for response data

size_t *resp_data_size

size of response data buffer, updated to received size

Description

Performs an arbitrary NVMe MI command, using the provided request data, in mi_req. The size of the request data payload is specified in req_data_size - this does not include the standard header length (so a header-only request would have a size of 0). Note that the Management Request Doublewords are considered part of the header data.

On success, response data is stored in mi_resp, which has an optional appended payload buffer of resp_data_size bytes. The actual payload size transferred will be stored in resp_data_size. This size does not include the MI response header, so 0 represents no payload.

See: struct nvme_mi_mi_req_hdr and struct nvme_mi_mi_resp_hdr.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_read_mi_data_subsys(libnvme_mi_ep_t ep, struct nvme_mi_read_nvm_ss_info *s)

Perform a Read MI Data Structure command, retrieving subsystem data.

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

struct nvme_mi_read_nvm_ss_info *s

subsystem information to populate

Description

Retrieves the Subsystem information - number of external ports and NVMe version information. See struct nvme_mi_read_nvm_ss_info.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_read_mi_data_port(libnvme_mi_ep_t ep, __u8 portid, struct nvme_mi_read_port_info *p)

Perform a Read MI Data Structure command, retrieving port data.

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 portid

id of port data to retrieve

struct nvme_mi_read_port_info *p

port information to populate

Description

Retrieves the Port information, for the specified port ID. The subsystem data (from libnvme_mi_mi_read_mi_data_subsys) nmp field contains the allowed range of port IDs.

See struct nvme_mi_read_port_info.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_read_mi_data_ctrl_list(libnvme_mi_ep_t ep, __u8 start_ctrlid, struct nvme_ctrl_list *list)

Perform a Read MI Data Structure command, retrieving the list of attached controllers.

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 start_ctrlid

starting controller ID

struct nvme_ctrl_list *list

controller list to populate

Description

Retrieves the list of attached controllers, with IDs greater than or equal to start_ctrlid.

See struct nvme_ctrl_list.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_read_mi_data_ctrl(libnvme_mi_ep_t ep, __u16 ctrl_id, struct nvme_mi_read_ctrl_info *ctrl)

Perform a Read MI Data Structure command, retrieving controller information

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u16 ctrl_id

ID of controller to query

struct nvme_mi_read_ctrl_info *ctrl

controller data to populate

Description

Retrieves the Controller Information Data Structure for the attached controller with ID ctrlid.

See struct nvme_mi_read_ctrl_info.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_subsystem_health_status_poll(libnvme_mi_ep_t ep, bool clear, struct nvme_mi_nvm_ss_health_status *nshds)

Read the Subsystem Health Data Structure from the NVM subsystem

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

bool clear

flag to clear the Composite Controller Status state

struct nvme_mi_nvm_ss_health_status *nshds

subsystem health status data to populate

Description

Retrieves the Subsystem Health Data Structure into nshds. If clear is set, requests that the Composite Controller Status bits are cleared after the read. See NVMe-MI section 5.6 for details on the CCS bits.

See struct nvme_mi_nvm_ss_health_status.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_get(libnvme_mi_ep_t ep, __u32 dw0, __u32 dw1, __u32 *nmresp)

query a configuration parameter

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u32 dw0

management doubleword 0, containing configuration identifier, plus config-specific fields

__u32 dw1

management doubleword 0, config-specific.

__u32 *nmresp

set to queried configuration data in NMRESP field of response.

Description

Performs a MI Configuration Get command, with the configuration identifier as the LSB of dw0. Other dw0 and dw1 data is configuration-identifier specific.

On a successful Configuration Get, the nmresp pointer will be populated with the bytes from the 3-byte NMRESP field, converted to native endian.

See enum nvme_mi_config_id for identifiers.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_set(libnvme_mi_ep_t ep, __u32 dw0, __u32 dw1)

set a configuration parameter

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u32 dw0

management doubleword 0, containing configuration identifier, plus config-specific fields

__u32 dw1

management doubleword 0, config-specific.

Description

Performs a MI Configuration Set command, with the command as the LSB of dw0. Other dw0 and dw1 data is configuration-identifier specific.

See enum nvme_mi_config_id for identifiers.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_get_smbus_freq(libnvme_mi_ep_t ep, __u8 port, enum nvme_mi_config_smbus_freq *freq)

get configuration: SMBus port frequency

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 port

port ID to query

enum nvme_mi_config_smbus_freq *freq

output value for current frequency configuration

Description

Performs a MI Configuration Get, to query the current SMBus frequency of the port specified in port. On success, populates freq with the port frequency

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_set_smbus_freq(libnvme_mi_ep_t ep, __u8 port, enum nvme_mi_config_smbus_freq freq)

set configuration: SMBus port frequency

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 port

port ID to set

enum nvme_mi_config_smbus_freq freq

new frequency configuration

Description

Performs a MI Configuration Set, to update the current SMBus frequency of the port specified in port.

See struct nvme_mi_read_port_info for the maximum supported SMBus frequency for the port.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_set_health_status_change(libnvme_mi_ep_t ep, __u32 mask)

clear CCS bits in health status

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u32 mask

bitmask to clear

Description

Performs a MI Configuration Set, to update the current health status poll values of the Composite Controller Status bits. Bits set in mask will be cleared from future health status poll data, and may be re-triggered by a future health change event.

See libnvme_mi_mi_subsystem_health_status_poll`(), :c:type:`enum nvme_mi_ccs for values in mask.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_get_mctp_mtu(libnvme_mi_ep_t ep, __u8 port, __u16 *mtu)

get configuration: MCTP MTU

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 port

port ID to query

__u16 *mtu

output value for current MCTP MTU configuration

Description

Performs a MI Configuration Get, to query the current MCTP Maximum Transmission Unit size (MTU) of the port specified in port. On success, populates mtu with the MTU.

The default reset value is 64, corresponding to the MCTP baseline MTU.

Some controllers may also use this as the maximum receive unit size, and may not accept MCTP messages larger than the configured MTU.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_set_mctp_mtu(libnvme_mi_ep_t ep, __u8 port, __u16 mtu)

set configuration: MCTP MTU

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 port

port ID to set

__u16 mtu

new MTU configuration

Description

Performs a MI Configuration Set, to update the current MCTP MTU value for the port specified in port.

Some controllers may also use this as the maximum receive unit size, and may not accept MCTP messages larger than the configured MTU. When setting this value, you will likely need to change the MTU of the local MCTP interface(s) to match.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_get_async_event(libnvme_mi_ep_t ep, __u8 *aeelver, struct nvme_mi_aem_supported_list *list, size_t *list_num_bytes)

get configuration: Asynchronous Event

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 *aeelver

Asynchronous Event Enable List Version Number

struct nvme_mi_aem_supported_list *list

AE Supported list header and list contents

size_t *list_num_bytes

number of bytes in the list header and contents buffer. This will be populated with returned size of list and contents if successful.

Description

Performs a MI Configuration Get, to query the current enable Asynchronous Events. On success, populates aeelver and the list with current info,

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_mi_config_set_async_event(libnvme_mi_ep_t ep, bool envfa, bool empfa, bool encfa, __u8 aemd, __u8 aerd, struct nvme_mi_aem_enable_list *enable_list, size_t enable_list_size, struct nvme_mi_aem_occ_list_hdr *occ_list, size_t *occ_list_size)

set configuration: Asynchronous Event

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

bool envfa

Enable SR-IOV Virtual Functions AE

bool empfa

Enable SR-IOV Physical Functions AE

bool encfa

Enable PCI Functions AE.

__u8 aemd

AEM Delay Interval (for Sync only)

__u8 aerd

AEM Retry Delay (for Sync only; time in 100s of ms)

struct nvme_mi_aem_enable_list *enable_list

libnvme_mi_aem_enable_listucture containing header and items of events to be enabled or disabled. This is taken as a delta change from the current configuration.

size_t enable_list_size

Size of the enable_list including header and data. Meant to catch overrun issues.

struct nvme_mi_aem_occ_list_hdr *occ_list

Pointer to populate with the occurrence list (header and data)

size_t *occ_list_size

Total size of provided occ_list buffer. Will be updated with received size if successful

Description

Performs a MI Configuration Set, to ACK (sent after an AEM) or Sync (at anytime to enable or disable Asynchronous Events).

On success, populates occ_list. See TP6035a for details on how occ_list is populated in ACK versus Sync conditions

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_admin_xfer(struct libnvme_transport_handle *hdl, struct nvme_mi_admin_req_hdr *admin_req, size_t req_data_size, struct nvme_mi_admin_resp_hdr *admin_resp, off_t resp_data_offset, size_t *resp_data_size)

Raw admin transfer interface.

Parameters

struct libnvme_transport_handle *hdl

transport handle to send the admin command to

struct nvme_mi_admin_req_hdr *admin_req

request data

size_t req_data_size

size of request data payload

struct nvme_mi_admin_resp_hdr *admin_resp

buffer for response data

off_t resp_data_offset

offset into request data to retrieve from controller

size_t *resp_data_size

size of response data buffer, updated to received size

Description

Performs an arbitrary NVMe Admin command, using the provided request data, in admin_req. The size of the request data payload is specified in req_data_size - this does not include the standard header length (so a header-only request would have a size of 0).

On success, response data is stored in admin_resp, which has an optional appended payload buffer of resp_data_size bytes. The actual payload transferred will be stored in resp_data_size. These sizes do not include the Admin request header, so 0 represents no payload.

As with all Admin commands, we can request partial data from the Admin Response payload, offset by resp_data_offset.

See: struct nvme_mi_admin_req_hdr and struct nvme_mi_admin_resp_hdr.

Return

The nvme command status if a response was received (see enum nvme_status_field) or negative error code otherwise.

int libnvme_mi_control(libnvme_mi_ep_t ep, __u8 opcode, __u16 cpsp, __u16 *result_cpsr)

Perform a Control Primitive command

Parameters

libnvme_mi_ep_t ep

endpoint for MI communication

__u8 opcode

Control Primitive opcode (using enum nvme_mi_control_opcode)

__u16 cpsp

Control Primitive Specific Parameter

__u16 *result_cpsr

Optional field to return the result from the CPSR field

Description

Perform a Control Primitive command, using the opcode specified in opcode Stores the result from the CPSR field in result_cpsr if set.

See: enum nvme_mi_control_opcode

Return

0 on success, negative error code otherwise.

enum libnvme_mi_aem_handler_next_action

Next action for the AEM state machine handler

Constants

NVME_MI_AEM_HNA_ACK

Send an ack for the AEM

NVME_MI_AEM_HNA_NONE

No further action

Description

Used as return value for the AE callback generated when calling libnvme_mi_aem_process

struct libnvme_mi_event

AE event information structure

Definition

struct libnvme_mi_event {
  uint8_t aeoi;
  uint8_t aessi;
  uint32_t aeocidi;
  void *spec_info;
  size_t spec_info_len;
  void *vend_spec_info;
  size_t vend_spec_info_len;
};

Members

aeoi

Event identifier

aessi

Event occurrence scope info

aeocidi

Event occurrence scope ID info

spec_info

Specific info buffer

spec_info_len

Length of specific info buffer

vend_spec_info

Vendor specific info buffer

vend_spec_info_len

Length of vendor specific info buffer

Description

Application callbacks for libnvme_mi_aem_process will be able to call libnvme_mi_aem_get_next_event which will return a pointer to such an identifier for the next event the application should parse

struct libnvme_mi_event *libnvme_mi_aem_get_next_event(libnvme_mi_ep_t ep)

Get details for the next event to parse

Parameters

libnvme_mi_ep_t ep

The endpoint with the event

Description

When inside a aem_handler, call this and a returned struct pointer will provide details of event information. Will return NULL when end of parsing is occurred. spec_info and vend_spec_info must be copied to persist as they will not be valid after the handler_next_action has returned.

Return

Pointer no next libnvme_mi_event or NULL if this is the last one

struct libnvme_mi_aem_config

Provided for libnvme_mi_aem_enable

Definition

struct libnvme_mi_aem_config {
  enum libnvme_mi_aem_handler_next_action (*aem_handler)(libnvme_mi_ep_t ep,size_t num_events, void *userdata);
  struct libnvme_mi_aem_enabled_map enabled_map;
  bool envfa;
  bool empfa;
  bool encfa;
  __u8 aemd;
  __u8 aerd;
};

Members

aem_handler

Callback function for application processing of events

enabled_map

Map indicating which AE should be enabled on the endpoint

envfa

Enable SR-IOV virtual functions AE

empfa

Enable SR-IOV physical functions AE

encfa

Enable PCIe functions AE

aemd

AEM Delay (time in seconds from when event happens to AEM being batched and sent)

aerd

AEM Retry Delay (time in 100s of ms between AEM retries from the endpoint)

Description

Application callbacks for libnvme_mi_aem_process will be able to call libnvme_mi_aem_get_next_event which will return a pointer to such an identifier for the next event the application should parse

int libnvme_mi_aem_get_fd(libnvme_mi_ep_t ep)

Returns the pollable fd for AEM data available

Parameters

libnvme_mi_ep_t ep

The endpoint being monitored for asynchronous data

Description

This populated structure can be polled from the application to understand if a call to libnvme_mi_aem_process() is required (when a poll returns > 0).

Return

The fd value or -1 if error

int libnvme_mi_aem_enable(libnvme_mi_ep_t ep, struct libnvme_mi_aem_config *config, void *userdata)

Enable AE on the provided endpoint

Parameters

libnvme_mi_ep_t ep

Endpoint to enable AEs

struct libnvme_mi_aem_config *config

AE configuraiton including which events are enabled and the callback function

void *userdata

Application provided context pointer for callback function

Description

This function is called to enable AE on the endpoint. Endpoint will provide initial state (if any) of enabled AEs and application can parse those via the aem_handler fn pointer in callbacks. Thes can be obtained in the callback by calling libnvme_mi_aem_get_next_event().

Application should poll the fd that can be obtained from libnvme_mi_aem_get_fd and then call libnvme_mi_aem_process() when poll() indicates data available.

A call to libnvme_mi_aem_process() will grab AEM data and call the aem_handler fn pointer. At this point the application can call libnvme_mi_aem_get_next_event() to get information for each triggered event.

Return

0 on success, negative error code otherwise.

int libnvme_mi_aem_get_enabled(libnvme_mi_ep_t ep, struct libnvme_mi_aem_enabled_map *enabled)

Return information on which AEs are enabled

Parameters

libnvme_mi_ep_t ep

Endpoint to check enabled status

struct libnvme_mi_aem_enabled_map *enabled

libnvme_mi_aem_enabled_map indexed by AE event ID of enabled state

Return

0 on success, negative error code otherwise.

int libnvme_mi_aem_disable(libnvme_mi_ep_t ep)

Disable AE on the provided endpoint

Parameters

libnvme_mi_ep_t ep

Endpoint to disable AEs

Return

0 on success, negative error code otherwise.

int libnvme_mi_aem_process(libnvme_mi_ep_t ep, void *userdata)

Process AEM on the provided endpoint

Parameters

libnvme_mi_ep_t ep

Endpoint to process

void *userdata

Application provided context pointer for callback function

Description

Call this if poll() indicates data is available on the fd provided by libnvme_mi_aem_get_fd()

This will call the fn pointer, aem_handler, provided with libnvme_mi_aem_config and the application can call libnvme_mi_aem_get_next_event() from within this callback to get aem event data. The callback function should return NVME_MI_AEM_HNA_ACK for normal operation.

Return

0 on success, negative error code otherwise.

void *libnvme_mi_submit_entry(__u8 type, const struct nvme_mi_msg_hdr *hdr, size_t hdr_len, const void *data, size_t data_len)

Weak hook called before an MI message is sent.

Parameters

__u8 type

MCTP message type

const struct nvme_mi_msg_hdr *hdr

Pointer to the MI message header

size_t hdr_len

Length of the message header in bytes

const void *data

Pointer to message payload data

size_t data_len

Length of payload data in bytes

Description

This is a weak symbol that can be overridden by an application to intercept outgoing MI messages for tracing or testing purposes. The return value is passed back as user_data to the matching libnvme_mi_submit_exit() call.

Return

An opaque pointer passed to libnvme_mi_submit_exit(), or NULL.

void libnvme_mi_submit_exit(__u8 type, const struct nvme_mi_msg_hdr *hdr, size_t hdr_len, const void *data, size_t data_len, void *user_data)

Weak hook called after an MI message completes.

Parameters

__u8 type

MCTP message type

const struct nvme_mi_msg_hdr *hdr

Pointer to the MI response message header

size_t hdr_len

Length of the response message header in bytes

const void *data

Pointer to response payload data

size_t data_len

Length of response payload data in bytes

void *user_data

Value returned by the matching libnvme_mi_submit_entry() call

Description

This is a weak symbol that can be overridden by an application to intercept completed MI transactions. Called with the opaque pointer returned by the corresponding libnvme_mi_submit_entry() call.