diff options
| author | Yishai Hadas <yishaih@nvidia.com> | 2026-02-01 16:34:05 +0200 |
|---|---|---|
| committer | Leon Romanovsky <leon@kernel.org> | 2026-02-08 23:50:41 -0500 |
| commit | 0ac6f4056c4a257f4b230b910e3e6fee6c6fc9b9 (patch) | |
| tree | 72c49a04acc7a3142449b520879ee13775d56a81 /include/uapi/rdma | |
| parent | 9ad95a0f2b75a788325249f341694e0343facf7b (diff) | |
RDMA/uverbs: Add DMABUF object type and operations
Expose DMABUF functionality to userspace through the uverbs interface,
enabling InfiniBand/RDMA devices to export PCI based memory regions
(e.g. device memory) as DMABUF file descriptors. This allows
zero-copy sharing of RDMA memory with other subsystems that support the
dma-buf framework.
A new UVERBS_OBJECT_DMABUF object type and allocation method were
introduced.
During allocation, uverbs invokes the driver to supply the
rdma_user_mmap_entry associated with the given page offset (pgoff).
Based on the returned rdma_user_mmap_entry, uverbs requests the driver
to provide the corresponding physical-memory details as well as the
driver’s PCI provider information.
Using this information, dma_buf_export() is called; if it succeeds,
uobj->object is set to the underlying file pointer returned by the
dma-buf framework.
The file descriptor number follows the standard uverbs allocation flow,
but the file pointer comes from the dma-buf subsystem, including its own
fops and private data.
When an mmap entry is removed, uverbs iterates over its associated
DMABUFs, marks them as revoked, and calls dma_buf_move_notify() so that
their importers are notified.
The same procedure applies during the disassociate flow; final cleanup
occurs when the application closes the file.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
Link: https://patch.msgid.link/20260201-dmabuf-export-v3-2-da238b614fe3@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Diffstat (limited to 'include/uapi/rdma')
| -rw-r--r-- | include/uapi/rdma/ib_user_ioctl_cmds.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/uapi/rdma/ib_user_ioctl_cmds.h b/include/uapi/rdma/ib_user_ioctl_cmds.h index 35da4026f452..72041c1b0ea5 100644 --- a/include/uapi/rdma/ib_user_ioctl_cmds.h +++ b/include/uapi/rdma/ib_user_ioctl_cmds.h @@ -56,6 +56,7 @@ enum uverbs_default_objects { UVERBS_OBJECT_COUNTERS, UVERBS_OBJECT_ASYNC_EVENT, UVERBS_OBJECT_DMAH, + UVERBS_OBJECT_DMABUF, }; enum { @@ -263,6 +264,15 @@ enum uverbs_methods_dmah { UVERBS_METHOD_DMAH_FREE, }; +enum uverbs_attrs_alloc_dmabuf_cmd_attr_ids { + UVERBS_ATTR_ALLOC_DMABUF_HANDLE, + UVERBS_ATTR_ALLOC_DMABUF_PGOFF, +}; + +enum uverbs_methods_dmabuf { + UVERBS_METHOD_DMABUF_ALLOC, +}; + enum uverbs_attrs_reg_dm_mr_cmd_attr_ids { UVERBS_ATTR_REG_DM_MR_HANDLE, UVERBS_ATTR_REG_DM_MR_OFFSET, |