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NAME | SYNOPSIS | DESCRIPTION | ARGUMENTS | RETURN VALUE | SEE ALSO | COLOPHON |
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mlx5dv_devx_ume...devx_umem_dereg(3) mlx5dv_devx_ume...devx_umem_dereg(3)
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
#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)
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.
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.
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).
mlx5dv_open_device(3), ibv_reg_mr(3), mlx5dv_devx_obj_create(3)
#AUTHOR
Yishai Hadas ⟨[email protected]⟩
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
[email protected]. 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
[email protected]
mlx5dv_devx_ume...devx_umem_dereg(3)
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HTML rendering created 2025-09-06 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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