plucky (3) mlx5dv_devx_umem_reg_ex.3.gz
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)