fi_provider - Man Page

Name

fi_prov_ini — External provider entry point

fi_param_define / fi_param_get

Register and retrieve environment variables with the libfabric core

fi_log_enabled / fi_log

Control and output debug logging information.

fi_open / fi_close

Open a named library object

fi_export_fid / fi_import_fid

Share a fabric object between different providers or resources

Synopsis

#include <rdma/fabric.h>
#include <rdma/prov/fi_prov.h>

struct fi_provider* fi_prov_ini(void);

int fi_param_define(const struct fi_provider *provider, const char *param_name,
    enum fi_param_type type, const char *help_string_fmt, ...);

int fi_param_get_str(struct fi_provider *provider, const char *param_name,
    char **value);

int fi_param_get_int(struct fi_provider *provider, const char *param_name,
    int *value);

int fi_param_get_bool(struct fi_provider *provider, const char *param_name,
    int *value);

int fi_param_get_size_t(struct fi_provider *provider, const char *param_name,
    size_t *value);
#include <rdma/fabric.h>
#include <rdma/prov/fi_prov.h>
#include <rdma/prov/fi_log.h>

int fi_log_enabled(const struct fi_provider *prov, enum fi_log_level level,
    enum fi_log_subsys subsys);

void fi_log(const struct fi_provider *prov, enum fi_log_level level,
    enum fi_log_subsys subsys, const char *func, int line,
    const char *fmt, ...);
#include <rdma/fabric.h>

int fi_open(uint32_t version, const char *name, void *attr,
    size_t attr_len, uint64_t flags, struct fid **fid, void *context);

int fi_close(struct fid *fid);
#include <rdma/fabric.h>
#include <rdma/fi_ext.h>

int fi_export_fid(struct fid *fid, uint64_t flags,
    struct fid **expfid, void *context);

int fi_import_fid(struct fid *fid, struct fid *expfid, uint64_t flags);

Arguments

provider

Reference to the provider.

version

API version requested by application.

name

Well-known name of the library object to open.

attr

Optional attributes of object to open.

attr_len

Size of any attribute structure passed to fi_open. Should be 0 if no attributes are give.

fid

Returned fabric identifier for opened object.

Description

A fabric provider implements the application facing software interfaces needed to access network specific protocols, drivers, and hardware. The interfaces and structures defined by this man page are exported by the libfabric library, but are targeted for provider implementations, rather than for direct use by most applications.

Integrated providers are those built directly into the libfabric library itself. External providers are loaded dynamically by libfabric at initialization time. External providers must be in a standard library path or in the libfabric library search path as specified by environment variable. Additionally, external providers must be named with the suffix “-fi.so” at the end of the name.

Named objects are special purpose resources which are accessible directly to applications. They may be used to enhance or modify the behavior of library core. For details, see the fi_open call below.

fi_prov_ini

This entry point must be defined by external providers. On loading, libfabric will invoke fi_prov_ini() to retrieve the provider’s fi_provider structure. Additional interactions between the libfabric core and the provider will be through the interfaces defined by that struct.

fi_param_define

Defines a configuration parameter for use by a specified provider. The help_string and param_name arguments must be non-NULL, help_string must additionally be non-empty. They are copied internally and may be freed after calling fi_param_define.

fi_param_get

Gets the value of a configuration parameter previously defined using fi_param_define(). The value comes from the environment variable name of the form FI__, all converted to upper case.

If the parameter was previously defined and the user set a value, FI_SUCCESS is returned and (*value) points to the retrieved value.

If the parameter name was previously defined, but the user did not set a value, -FI_ENODATA is returned and the value of (*value) is unchanged.

If the parameter name was not previously defined via fi_param_define(), -FI_ENOENT will be returned and the value of (*value) is unchanged.

If the value in the environment is not valid for the parameter type, -FI_EINVAL will be returned and the value of (*value) is unchanged.

fi_log_enabled / fi_log

Todo

fi_open

Open a library resource using a well-known name. This feature allows applications and providers a mechanism which can be used to modify or enhance core library services and behavior. The details are specific based on the requested object name. Most applications will not need this level of control.

The library API version known to the application should be provided through the version parameter. The use of attributes is object dependent. If required, attributes should be provided through the attr parameter, with attr_len set to the size of the referenced attribute structure. The following is a list of published names, along with descriptions of the service or resource to which they correspond.

mr_cache

The mr_cache object references the internal memory registration cache used by the different providers. Additional information on the cache is available in the fi_mr(3) man page.

fi_export_fid / fi_import_fid

Generally, fabric objects are allocated and managed entirely by a single provider. Typically only the application facing software interfaces of a fabric object are defined, for example, the message or tagged operations of an endpoint. The fi_export_fid and fi_import_fid calls provide a a mechanism by which provider facing APIs may be accessed. This allows the creation of fid objects that are shareable between providers, or for library plug-in services. The ability to export a shareable object is object and provider implementation dependent.

Shareable fids typically contain at least 3 main components: a base fid, a set of exporter defined ops, and a set of importer defined ops.

Notes

Todo

Provider Interface

The fi_provider structure defines entry points for the libfabric core to use to access the provider. All other calls into a provider are through function pointers associated with allocated objects.

struct fi_provider {
    uint32_t version;
    uint32_t fi_version;
    struct fi_context context;
    const char *name;
    int (*getinfo)(uint32_t version, const char *node, const char *service,
            uint64_t flags, const struct fi_info *hints,
            struct fi_info **info);
    int (*fabric)(struct fi_fabric_attr *attr, struct fid_fabric **fabric,
            void *context);
    void    (*cleanup)(void);
};

version

The provider version. For providers integrated with the library, this is often the same as the library version.

fi_version

The library interface version that the provider was implemented against. The provider’s fi_version must be greater than or equal to an application’s requested api version for the application to use the provider. It is a provider’s responsibility to support older versions of the api if it wishes to supports legacy applications. For integrated providers

Todo

Return Value

Returns FI_SUCCESS on success. On error, a negative value corresponding to fabric errno is returned. Fabric errno values are defined in rdma/fi_errno.h.

Errors

See Also

fabric(7), fi_getinfo(3) fi_mr(3),

Authors

OpenFabrics.

Referenced By

fi_getinfo(3).

The man page fi_open(3) is an alias of fi_provider(3).

2021-06-17 Libfabric Programmer’s Manual Libfabric v1.13.1