[KVConnector][MoRIIO] Transfer hybrid mamba/KDA recurrent state in READ mode - #51052
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Documentation preview: https://vllm--51052.org.readthedocs.build/en/51052/ |
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This pull request has merge conflicts that must be resolved before it can be |
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@YukioZzz what's the path to merge here? |
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cc @inkcherry |
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hi @YukioZzz has this been tested on agentic long context multi turn workloads yet like agentx-fast? |
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I’m not a MoRI expert, so I’ll defer the lower-level MoRI/RDMA details to other engineers, but from the vLLM/KVConnector side the approach looks reasonable to me. The scope is also fairly well contained: READ mode, homogeneous TP/DCP, with unsupported WRITE/speculative/heterogeneous-TP cases explicitly gated. The main concern I noticed is failure recovery. For hybrid KDA/Mamba reads, a transfer failure currently fails the step closed because vLLM does not yet have group-aware recovery for multiple KV-cache groups. I think that is acceptable for the initial K3 enablement, but we should make sure it is tracked as a follow-up. It would also help to add the AgentX test command/config and the perf/accuracy result to the PR, as we are already seeing good results. Overall, I don’t see an obvious blocker from the vLLM integration side. |
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Thanks AMD team for the work here. Following on from the comment from simon on august 8, a month ago, #51052 (comment) what is the path & ETA to merging this? |
Thanks for the review. For failure recovery, I agree with the proposed boundary. The request-scoped、group-aware HMA recovery is not the "transmission of KDA state" itself, but a general failure recovery strategy which will focus on how the scheduler rolls back external hits, releases blocks, and re-schedules local computations after a transmission failure, based on requests and cache groups. It will be handled in the follow-up PR. I added the AgentX command/config and results to the PR description. The production validation used Kimi-K3 1P1D, TP8/DCP8 on both roles, MoRIIO RDMA READ, FP8 KV, effective interleave 1536, P LMCacheMP, full graphs, no speculation, and AgentX c40 for one hour. It completed 2,019 valid requests with 3 empty-response errors, 70,236.35 input tok/s and 478.10 output tok/s. Final-head accuracy was separately validated with Kimi-K3 GSM8K full/c64 at 1,279/1,319 with zero request errors. All ranks used RDMA, all decode ranks completed the eager handshake, and the final logs had no MR registration failure, WR flush, HSA fault, transfer error, or engine failure. To keep this PR's scope stable, DSpark support is split into draft #57700 and stacked on this head. Once #51052 merges, #57700 will reduces to its three-commit DSpark-only delta manually. With DSpark enabled, the tput/tpot will be better, the detailed result will be posted there. |
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cc @tanpinsiang @junkang1991 @vllmellm : can you help to review/validate this PR? Thanks |
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✅ @YukioZzz, CI is now available for this PR.
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/amd-ci run |
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/ci run |
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❌ This PR is 65 commits behind upstream |
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/ci run |
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❌ This PR is 1 commit behind upstream |
READ mode declares load_kv_async=False, which promises the KV is in place by the time the forward runs. Three gaps in keeping that promise: - wait_for_layer_load spun in Python at 1 ms granularity, holding the GIL for the length of the transfer while the threads it waits on need it. Block inside mori via IOEngine.wait_all instead, with the GIL released and one deadline shared across the batch. Builds without the batched wait keep the spin as _poll_transfers_until_done; availability is probed once and cached so an older mori falls back instead of raising on the first transfer. - CUDAGraphMode.FULL cannot host a host-side blocking wait, so the step's statuses are drained in start_load_kv for that case only. - A failed or timed-out read was only logged, leaving the request to expire on a timeout after the forward had already run on incomplete KV. Report its destination blocks through get_block_ids_with_load_errors so the scheduler recomputes the affected prefix. TransferBatchState + poll_transfer_batch give the non-blocking verdict over a request's statuses. It stays a Python scan even where wait_all exists: mori's zero-timeout wait runs PollProgress on the calling thread, which would drive the backend's progress callback from the engine thread alongside its own poller. Tests: transfer-completion coverage over both mori generations -- batch verdicts, the availability probe, blocking until terminal, per-status detail recovered from a batch return code, and that the non-blocking poll never calls into mori. Signed-off-by: Yichao Zhu <Yichao.Zhu@amd.com>
Layout groundwork for transferring the conv + ssm recurrent state of hybrid (mamba/KDA) models. No control flow is wired up yet: this makes the state addressable, the follow-up moves it. A layer was assumed to own exactly one registered memory region, and sessions were indexed by the layer's position in the registration dict. A KDA layer owns two (conv and ssm), so build one session per registered region in registration order and look them up through _region_session_indices(layer_name). For an attention layer this is a single index and the resulting sessions, offsets and transfers are unchanged. On top of that addressing: - MambaTransferGeometry describes a KDA layer's slot-strided conv/ssm views; kda_conv_ssm unpacks both supported cache layouts (a legacy (conv, ssm) tuple, and the packed [num_blocks, 1, 1, page_bytes] page reinterpreted per MambaSpec.shapes/dtypes exactly as MambaBase.bind_kv_cache does). - Both tensors are non-contiguous slot-strided views, which register_torch_tensor rejects, so each is registered through a zero-copy contiguous uint8 alias over its byte extent, clamped to the bytes remaining from the view's storage offset. - MambaOffsetTemplate captures the homogeneous-TP conv sub-projection and ssm geometry once, then applies request-specific slot bases without duplicating the offset arithmetic. - Heterogeneous TP is gated with NotImplementedError: it needs the remote page's slot stride and, for P_TP > D_TP, a multi-rank gather. Nothing moves the recurrent state yet, so serving a hybrid model would silently start every decode from a zero state. register_kv_caches refuses hybrid models until the transfer lands in the follow-up. Tests: slot-strided geometry, conv+ssm offsets under homogeneous TP, and the heterogeneous-TP gate. Signed-off-by: Yichao Zhu <Yichao.Zhu@amd.com>
Transfer packed recurrent state alongside attention KV in homogeneous-TP READ mode. - Preserve each transferable Mamba cache group's block table in the existing block-id payload and map every KDA layer to its own group. - Mirror MambaBase's packed-page views without copying, including strided blocks in a shared allocation. - Reject WRITE mode, speculative decoding, heterogeneous TP, incompatible Mamba group specs, and unsupported state layouts. - Recompute the final prompt token on decode and transfer recurrent state even on a full local attention hit. - Wait for both conv and SSM reads before forward, and release producer blocks when a read request aborts before decode allocation. Tests cover group mapping, packed-page aliasing, support gates, abort cleanup, and request-level transfer completion. Signed-off-by: Yichao Zhu <Yichao.Zhu@amd.com>
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✅ Triggered Buildkite CI #90041 for commit |
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✅ Triggered Buildkite AMD CI #13261 for commit |
Signed-off-by: Yichao Zhu <Yichao.Zhu@amd.com>
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/ci run --allow-stale |
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/amd-ci run |
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✅ Triggered Buildkite CI #90056 for commit
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❌ This PR is 4 commits behind upstream |
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✅ Triggered Buildkite AMD CI #13267 for commit
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7 participants
Purpose
Enable MoRIIO READ-mode disaggregated serving for hybrid attention plus Mamba/KDA models with homogeneous prefill/decode TP. Recurrent conv and SSM state must move with attention KV; otherwise decode starts from empty state.
The scope is deliberately narrow: READ mode, no speculative decoding, and equal producer/consumer TP. Hybrid WRITE and heterogeneous-TP recurrent-state relayout remain follow-ups.
Design
The three commits separate completion semantics, memory registration, and the READ data path:
Important constraints and behavior:
[B, 1, 1, C]byte pages are unpacked with the samesqueeze -> slice -> viewcontract asMambaBase.bind_kv_cache. This stays zero-copy when blocks are strided inside a shared multi-layer allocation.h(N-1)and decode recomputes the last prompt token to deriveh(N). Recurrent state is transferred even on a full local attention hit.The router protocol is unchanged. Attention and Mamba block groups continue to use
remote_block_ids; no KDA-specific side channel is added.Validation
Final head:
04412570c03493fbdaea4848fbf4134f2a266e96Focused ROCm + mori unit suite on MI355X:
Real-weight Kimi-Linear validation on two MI355X nodes:
The result matches the established
44/50baseline. Both ranks on both roles selected RDMA, both decode ranks completed eager handshake, and both roles registered 20 KDA layers. Final logs contain no traceback, EngineCore failure, MR-registration failure, WR flush, HSA fault, orTransferError.After six independent review/fix/validation rounds, the final head also passed full Kimi-K3 validation:
All eight ranks on both roles selected RDMA and registered 69 KDA layers; all eight decode ranks completed eager handshake. The final K3 logs contain none of the hard errors listed above.
AgentX long-context validation
The production K3 stack was also exercised with the public SemiAnalysis AgentX trace. This run used the same MoRIIO hybrid READ path plus DCP support that is already in current main:
The benchmark command was:
One-hour c40 result:
The final #51052 head was separately revalidated for accuracy with Kimi-K3 GSM8K full/c64 (
1279/1319, zero request errors). The AgentX run validates the long-context production stack; the GSM8K run isolates final-head correctness.Failure semantics
Hybrid READ failures fail closed before forward execution. Current scheduler invalid-block recovery is single-group-oriented and cannot safely reconstruct recurrent state, so request-level HMA recovery is left to a separate change.
Out of scope
AI assistance
AI assistance was used for analysis, implementation, and validation. The changes and recorded evidence still require maintainer review.