[omor1]

Motivation

Registering dmabuf-backed mlx5 umem regions using DevX is broken due to incorrect API usage, resulting in runtime errors if the backing memory for the SQ, CQ, and dbrec is changed from host to device memory on a system using dmabuf.

The mlx5 provider currently places the SQ, CQ, and dbrec in host memory rather than device memory, so this feature is not currently used.

Technical Details

Registering dmabuf-backed regions using mlx5dv_devx_umem_reg_ex requires passing in the dmabuf offset as mlx5dv_devx_umem_in::addr rather than the actual address of the buffer.

Issue Tracking

Test Plan

Validate correct registration of dmabuf-backed umem regions on mlx5 hardware.

Test Result

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/rocm-systems/blob/develop/CONTRIBUTING.md.

[therock-pr-bot]

❌ PR Check — Action Required

Check	Status	Details
📝 PR Description	❌ Fail	Error: PR description must reference a JIRA ID, ISSUE ID, or a GitHub closing keyword. Expected: include a JIRA ID / ISSUE ID line (separator : or -, or omitted; value may be a JIRA key, a number with/without #, or a link), OR a closing keyword + issue reference. Accepted examples: • JIRA ID : TESTAUTO-6039 • JIRA ID - #330 • JIRA ID #330 • JIRA ID (on separate line) ROCM-25757 • ISSUE ID : TESTUTO-3334 • ISSUE ID #3334 • ISSUE ID - TESTAUTO-3433 • ISSUE ID (on separate line) AIRUNTIME-2352 • ISSUE ID : https://github.com/<org_name>/<repo_name>/issues/1234 • Closes #10 • Fixes octo-org/octo-repo#100 • Resolves: #123 • #123 • https://github.com/<org_name>/<repo_name>/issues/123 Current: no valid JIRA/ISSUE/closing-keyword reference found
⛔ Forbidden Files	✅ Pass	—
🧪 Unit Test	⚠️ Warning	Error: Source/code files changed without an accompanying unit test. Expected: add at least one test file named like test_<name>.py / test_<name>.cpp (or <name>_test.*). Current: code file(s) changed: projects/rocshmem/src/gda/mlx5/provider_gda_mlx5.cpp; no test file found
🔎 pre-commit	⏳ Pending	⏳ Still running…
🚫 Draft PR	🔜 To Be Enabled	—
🚩 Feature Flag	🔜 To Be Enabled	—
📊 Code Coverage	🔜 To Be Enabled	—

⚠️ 1 policy check(s) failed. Please address the issues above before this PR can be Reviewed.

🚫 Please fix the failed policies

• ❌ PR Description

The Not ready to Review label was added to this PR. Once all policies pass, the label is removed automatically.

📖 Need help? See the Policy FAQ for details on every check and how to fix failures.

🙋 Wish to Override Policy?

[therock-pr-bot]

🚫 Please fix the failed policies before requesting reviews.

The following policy checks failed:

• ❌ PR Description

The Not ready to Review label has been added to this PR.
Once all policies pass, the label will be removed automatically.

[Copilot]

🟢 Approval recommended

The focused change matches the mlx5 DevX API contract and HSA-exported offset semantics.

0 open findings

What changed in this PR

Corrects mlx5 DevX registration for dma-buf-backed device memory.

Changes:

• Passes the exported dma-buf offset as mlx5dv_devx_umem_in::addr.

File	Description
projects/​rocshmem/​src/​gda/​mlx5/​provider_gda_mlx5.cpp	Fixes dma-buf UMEM registration address semantics.

🧠 Review effort: Balanced

---

💡 Add a code-review agent skill or configure MCP servers for context-aware, tailored reviews. Learn more in the docs.

[omor1]

There may be additional issues dmabuf-backed umem registrations, but I'm merging this for now until those issues can be evaluated. In any case this PR is very low-risk since we do not currently place QP structures in device memory, so we do not use dmabuf-backed umem registrations.

[systems-assistant]

TheRock Submodule Bump Activity

Newest first

• 2026-11-08 — Included in TheRock via ROCm/TheRock#9793.