mtmd: Add Vision Support for Minimax-M3 (#25113)

* Add preliminary MiniMax-M3 support

Text-only port that re-uses existing components: MiniMax-M2 style GQA with
per-head QK-norm and partial rotary, DeepSeek-V3 style leading-dense and
routed/shared experts, and swigluoai activation. Sparse attention is not
yet supported (dense fallback); vision tower and MTP heads are dropped.

* MiniMax-M3 vision tower (mmproj + clip graph)

* Delete m3_vision_ref.py

* Update clip.cpp

* MSA

* Update constants.py

* Update minimax.py

* Cache creation. Working withotu flash attention

* Added flash attention for sparse layers

* Decomposed slow cpu OP into GPU + CPU ops. Massive speedup over long ctx

* Rewrote indexer op to be cuda native. Modified flash attention to match per group block picking

* Implement sparse attention calc out of stock ops.

* Fix a cache allocation and cont issue

* Fixed -fa auto crash, flagged debug spots

* Delete vocab.json

* Delete model.safetensors.index.json

* Delete generation_config.json

* Delete Minimax directory

* Handled multi stream case to fall back on Dense Attention

* Development scaffolding cleanup. No functional change to the decode or
4-way paths. Full debug harness remains at <8136a9c68ed7a5eb009aa67bba3fda8062f4648f> for reproducing the
selection-parity validation.

* Remove redundant comment from minimax-m3.cpp

* Changed 3 Gelu Ops for vision into Gelu_erf ops

* Assert that n_kv is multiple of 128

* Rename MSA index tensors to indexer convention

Note: All GGUFs generated before this change will need to be regenerated.

* Fix incorrect Assert

* Review driven changes (#3)

* Remove comment from conversion minimax.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Remove whitespaces from constants.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Tighten comment in minimax.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* inherit MiniMax-M3 from MiniMax-M2

* drop dead text_config fallbacks

* Add indexer writer methods

* Reuse LLM_FFN_SWIGLU_OAI_MOE

* Remove duplicate  indexer setters, add only block_size/local_blocks, follow value naming convention

* Fix conversion error /gguf_writer.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Update gguf-py/gguf/gguf_writer.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Update gguf-py/gguf/tensor_mapping.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Update conversion/minimax.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Update conversion/minimax.py

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Remove whitespace in src/llama-kv-cache.cpp

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Remove Whitespace in Update src/llama-model.h

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Remove whitespace in src/llama-hparams.h

Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>

* Update minimax_m3.cpp

Rewrite code comment based on feedback and to better reflect the actual architecture, and reuse existing build_vit

* Rename minimax_m3.cpp to minimax-m3.cpp

* Update CMakeLists.txt

* Remove debug code from clip.cpp

* Update clip.cpp

* Update comments in tools/mtmd/models/minimax-m3.cpp

* Permute Q/K at conversion, drop precomputed sin/cos

* Log cache size on launch, block ctx shift, support prompt caching

Log indexer cache size on launch

Disallow ctx shift

Support prompt caching

* Update minimax-m3.cpp

* Optimize implementation, add multi stream support. 

Fully rewrote minimax-m3.cpp for speed and buffer size gains:

Unified the 4-way + decode, 1 FA call per layer instead of 4, with the groups mapped onto ne[3]

Custom CPU op now emits block-level mask, expanded on GPU, which causes CPU to GPU transfer to shrinks at prefill

Decode: ~25 nodes/layer vs ~50, no per-group concats/conts

Unified selection semantics, so both regimes rank bs + local bias (position-anchored local force), which means prefill/decode can no longer disagree on selection

can_reuse on the MSA bias input. Graph reuse at decode restored (was rebuilding the full graph every token)

In-place mask adds, shrinking compute buffer ~6.8 to ~4.2 GiB at ub2048/62k

Multi-stream: MSA now runs with -np N when kv_unified=false. Decode stays batched across streams (still 1 FA call), prefill loops per stream. dense fallback only for --kv-unified + multi-seq

Measured effect on expert offload bound setup: decode 6.2(4WAY)–7.15(MSA_decode) -> 7.7~7.8 t/s, flat from 5k to 60k+. prefill around 10% faster. buffer about 20% smaller, multi-user support.

* set default cache type to F32

* Fix potential DSA double indexer cache  allocation bug, only allocate in-cache k_idx for archs that opt in

* remove F16 downcasts in MSA attention, force F32 indexer score accum

* Add Minimax eos to llama vocab

* Guard edge case where idx cache can become stale after a tail trim

* Update llama-kv-cache.h

* Update llama-kv-cache.cpp

* Update llama-kv-cache.cpp

* Update llama-kv-cache.h

* Change resize Pad to none, resize alg to Bicubic Pillow

* Review driven changes

* Update llama-kv-cache.cpp

* rm unrotated pos_t

* fused rope w + pad

* rename merge --> merger for consistency

* add review skill for mtmd

* graph should use hparams n_merge

* fix lint

---------

Co-authored-by: Daniel Han <danielhanchen@gmail.com>
Co-authored-by: Sigbjørn Skjæret <1629204+CISC@users.noreply.github.com>
Co-authored-by: Xuan Son Nguyen <son@huggingface.co>

skills/code-review/SKILL.md

@@ -110,6 +110,15 @@ Public API changes carry a higher bar than internal ones (`CONTRIBUTING.md`). Re
 - Security: don't trust client-supplied headers (e.g. `X-Forwarded-For`) or add footguns; things like IP allowlisting belong at a reverse proxy unless there's a trusted-proxy design.
 - Wire new behavior into the existing request/response and checkpoint paths correctly; watch for resource leaks across requests.
 
+## Multimodal (`tools/mtmd/`)
+
+- Tensor names must be prefixed by `v.`, `a.`, `mm.` or `a.mm.` (legacy naming doesn't follow this convention - this is expected, but new code should follow it).
+- Do not use explicit sin/cos for RoPE; use `ggml_rope_ext` instead, see `HOWTO-add-model.md`. If it can't express the needed behavior, that's a design discussion, not a PR.
+- New GGML ops must not be introduced in the same PR, you must push it as a separate PR.
+- In most cases, `build_vit` should be enough to build the transformer graph for vision models. Do not add a loop to build the transformer graph manually, unless you have a very good reason to do so. If you do, please explain why in the PR description.
+- If you need a dedicated preprocessor, there is a high chance that it can be a derived class from one of the existing preprocessors. Check carefully before adding a new preprocessor class.
+- If the model need a new public API in `mtmd.h`, open a discussion first.
+
 ## General (always)
 
 Enforce the `AGENTS.md` / `CONTRIBUTING.md` coding and naming guidelines on every changed line - this is a distinct pass from checking that the code works, and matters just as much for review speed: