mlx5dv_var_export / mlx5dv_var_import / mlx5dv_var_unimport(3)

NAME
mlx5dv_var_export - Export VAR attributes for cross-process sharing

mlx5dv_var_import - Import a VAR from exported attributes

mlx5dv_var_unimport - Unimport a VAR

SYNOPSIS

        #include <infiniband/mlx5dv.h>
        int mlx5dv_var_export(struct mlx5dv_var *dv_var, void *data);
        struct mlx5dv_var *mlx5dv_var_import(struct ibv_context *context,
                                             void *data);
        void mlx5dv_var_unimport(struct mlx5dv_var *dv_var);

DESCRIPTION
These functions enable cross-process sharing of VAR objects.

mlx5dv_var_export() exports a VAR attributes into a data buffer. The buffer must be allocated by the caller with at least the size returned by mlx5dv_get_export_sizes() in the var_attrs_size field.

mlx5dv_var_import() returns a VAR that is associated with the exported attributes in the given context.

The context can be the original VAR allocating context or any context sharing the same kernel resources (e.g., via ibv_import_device()).

mlx5dv_var_unimport() unimports a VAR that was imported via mlx5dv_var_import(). Once the VAR usage has ended, either mlx5dv_free_var() or mlx5dv_var_unimport() should be called. mlx5dv_free_var() destroys the kernel object, while mlx5dv_var_unimport() only cleans up local resources without affecting the kernel object.

It is the responsibility of the application to coordinate between all contexts that use this VAR. Once destroy/free is done, no other process can use the object except for unimport. All users must collaborate to ensure this.

ARGUMENTS

  mlx5dv_var_export

dv_var
    The VAR object to export.

data
    Pointer to a buffer to be filled with the exported attributes. The buffer must be at least var_attrs_size bytes as returned by mlx5dv_get_export_sizes().

  mlx5dv_var_import

context
    RDMA device context to import the VAR into.

data
    Pointer to a buffer previously filled by mlx5dv_var_export().

RETURN VALUE
mlx5dv_var_export() returns 0 on success, or the value of errno on error.

mlx5dv_var_import() returns a pointer to a struct mlx5dv_var on success, or NULL on error with errno set.

SEE ALSO
mlx5dv_alloc_var, mlx5dv_get_export_sizes, mlx5dv_open_device

AUTHOR
Maher Sanalla msanalla@nvidia.com