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mlx5dv_alloc_var(3) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | ARGUMENTS | RETURN VALUE | SEE ALSO | AUTHOR | COLOPHON 

mlx5dv_alloc_va...mlx5dv_free_var(3) mlx5dv_alloc_va...mlx5dv_free_var(3)

NAME         top

       mlx5dv_alloc_var - Allocates a VAR

       mlx5dv_free_var - Frees a VAR

SYNOPSIS         top

              #include <infiniband/mlx5dv.h>

              struct mlx5dv_var *
              mlx5dv_alloc_var(struct ibv_context *context, uint32_t flags);

              void mlx5dv_free_var(struct mlx5dv_var *dv_var);

DESCRIPTION         top

       Create / free a VAR which can be used for some device commands
       over the DEVX interface.

       The DEVX API enables direct access from the user space area to the
       mlx5 device driver, the VAR information is needed for few commands
       related to Virtio.

ARGUMENTS         top

       context
              RDMA device context to work on.

       flags  Allocation flags for the UAR.

   dv_var
              struct mlx5dv_var {
                  uint32_t page_id;
                  uint32_t length;
                  off_t mmap_off;
                  uint64_t comp_mask;
              };

       page_id
              The device page id to be used.

       length The mmap length parameter to be used for mapping a VA to
              the allocated VAR entry.

       mmap_off
              The mmap offset parameter to be used for mapping a VA to
              the allocated VAR entry.

RETURN VALUE         top

       Upon success mlx5dv_alloc_var returns a pointer to the created VAR
       ,on error NULL will be returned and errno will be set.

SEE ALSO         top

       mlx5dv_open_device, mlx5dv_devx_obj_create

AUTHOR         top

       Yishai Hadas ⟨yishaih@mellanox.com⟩

COLOPHON         top

       This page is part of the rdma-core (RDMA Core Userspace Libraries
       and Daemons) project.  Information about the project can be found
       at ⟨https://github.com/linux-rdma/rdma-core⟩.  If you have a bug
       report for this manual page, send it to
       linux-rdma@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2025-08-11.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2025-08-04.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there is
       a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

                                     mlx5dv_alloc_va...mlx5dv_free_var(3)

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