NAME

       mlx5dv_devx_umem_reg - Register a user memory to be used by the devx interface

       mlx5dv_devx_umem_reg_ex - Register a user memory to be used by the devx interface

       mlx5dv_devx_umem_dereg - Deregister a devx umem object

SYNOPSIS

              #include <infiniband/mlx5dv.h>

              struct mlx5dv_devx_umem {
                  uint32_t umem_id;
              };

              struct mlx5dv_devx_umem *
              mlx5dv_devx_umem_reg(struct ibv_context *context, void *addr, size_t size,
                           uint32_t access)

              struct mlx5dv_devx_umem_in {
                  void *addr;
                  size_t size;
                  uint32_t access;
                  uint64_t pgsz_bitmap;
                  uint64_t comp_mask;
                  int dmabuf_fd;
              };

              struct mlx5dv_devx_umem *
              mlx5dv_devx_umem_reg_ex(struct ibv_context *ctx, struct mlx5dv_devx_umem_in *umem_in);

              int mlx5dv_devx_umem_dereg(struct mlx5dv_devx_umem *dv_devx_umem)

DESCRIPTION

       Register or deregister a user memory to be used by the devx interface.

       The  register  verb  exposes a UMEM DEVX object for user memory registration for DMA.  The
       API to register the user memory gets as input the user address, length and  access  flags,
       and  provides  to  the  user  as  output an object which holds the UMEM ID returned by the
       firmware to this registered memory.

       The user can ask for specific page sizes for the given address and length,  in  that  case
       mlx5dv_devx_umem_reg_ex()  should  be  used.   In case the kernel couldn’t find a matching
       page size from the given umem_in->pgsz_bitmap bitmap the API will fail.

       The user will use that UMEM ID in device direct commands that use this memory  instead  of
       the physical addresses list, for example upon mlx5dv_devx_obj_create to create a QP.

ARGUMENTS

       context

              RDMA device context to create the action on.

       addr   The memory start address to register.

       size

              The size of *addr* buffer.

       access The  desired  memory protection attributes; it is either 0 or the bitwise OR of one
              or more of enum ibv_access_flags.

       umem_in
              A structure holds the argument bundle.

       pgsz_bitmap
              Represents the required page sizes.  umem  creation  will  fail  if  it  cannot  be
              created with these page sizes.

       comp_mask
              Flags indicating the additional fields.

       dmabuf_fd
              If  MLX5DV_UMEM_MASK_DMABUF  is  set in comp_mask then this value must be a FD of a
              dmabuf.  In this mode the dmabuf is used as the backing memory to create  the  umem
              out  of.   The dmabuf must be pinnable.  addr is interpreted as the starting offset
              of the dmabuf.

RETURN VALUE

       Upon success mlx5dv_devx_umem_reg /  mlx5dv_devx_umem_reg_ex  will  return  a  new  struct
       mlx5dv_devx_umem object, on error NULL will be returned and errno will be set.

       mlx5dv_devx_umem_dereg  returns  0  on  success,  or  the value of errno on failure (which
       indicates the failure reason).

SEE ALSO

       mlx5dv_open_device(3), ibv_reg_mr(3), mlx5dv_devx_obj_create(3)

       #AUTHOR

       Yishai Hadas <yishaih@mellanox.com>

                                                  mlx5dv_devx_umem_reg, mlx5dv_devx_umem_dereg(3)