Files
vllm/tests/v1/kv_offload/test_factory.py
b6ff8a2f50 [Core] Add MRV2 virtual-batch PCP for MLA (#46570)
Signed-off-by: Lucas Wilkinson <lwilkins@redhat.com>
Signed-off-by: Matthew Bonanni <mbonanni@redhat.com>
Co-authored-by: Codex <noreply@openai.com>
Co-authored-by: OpenAI Codex <codex@openai.com>
Co-authored-by: Matthew Bonanni <mbonanni@redhat.com>
2026-07-19 02:53:15 +00:00

652 lines
22 KiB
Python

# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Unit tests for OffloadingSpecFactory.
These tests verify:
1. Pre-registration integrity — registered module paths can actually import
and yield correct OffloadingSpec subclasses (CI sentinel against file moves).
2. End-to-end factory → spec construction with real configs.
3. Downstream collaboration — build_metric_definitions delegation.
4. Error paths — unregistered specs, missing config, duplicate registration.
"""
from typing import cast
from unittest.mock import MagicMock, patch
import pytest
import torch
from vllm.config import KVTransferConfig, ParallelConfig, VllmConfig
from vllm.distributed.kv_transfer.kv_connector.v1.offloading.config import (
build_offloading_config,
)
from vllm.platforms import current_platform
from vllm.v1.kv_cache_interface import (
FullAttentionSpec,
KVCacheConfig,
KVCacheGroupSpec,
KVCacheTensor,
MLAAttentionSpec,
SlidingWindowSpec,
)
from vllm.v1.kv_offload.base import (
CanonicalKVCaches,
OffloadingHistogramMetadata,
OffloadingManager,
OffloadingSpec,
OffloadingWorker,
)
from vllm.v1.kv_offload.cpu.shared_offload_region import SharedOffloadRegion
from vllm.v1.kv_offload.cpu.spec import CPUOffloadingSpec
from vllm.v1.kv_offload.factory import OffloadingSpecFactory
from vllm.v1.kv_offload.tiering.spec import TieringOffloadingSpec
# ---------------------------------------------------------------------------
# Fixtures
# ---------------------------------------------------------------------------
@pytest.fixture(autouse=True)
def restore_registry():
"""Save and restore OffloadingSpecFactory._registry between tests."""
original = dict(OffloadingSpecFactory._registry)
yield
OffloadingSpecFactory._registry = original
def _get_extra_config(config: VllmConfig) -> dict:
assert config.kv_transfer_config is not None
return config.kv_transfer_config.kv_connector_extra_config
def _create_spec(config: VllmConfig, kv_cache_config: KVCacheConfig) -> OffloadingSpec:
return OffloadingSpecFactory.create_spec(
build_offloading_config(config, kv_cache_config)
)
def _make_vllm_config(
spec_name: str | None = "CPUOffloadingSpec",
cpu_bytes_to_use: int | None = None,
store_threshold: int = 0,
extra_config: dict | None = None,
):
"""Build a real VllmConfig with kv_transfer_config set for offloading."""
from vllm.config import (
CacheConfig,
DeviceConfig,
ModelConfig,
SchedulerConfig,
VllmConfig,
)
model_config = ModelConfig(
model="facebook/opt-125m",
trust_remote_code=True,
dtype="float16",
seed=42,
)
scheduler_config = SchedulerConfig(
max_num_seqs=16,
max_num_batched_tokens=64,
max_model_len=10000,
enable_chunked_prefill=True,
is_encoder_decoder=model_config.is_encoder_decoder,
)
cache_config = CacheConfig(
block_size=16,
gpu_memory_utilization=0.9,
cache_dtype="auto",
enable_prefix_caching=True,
)
cfg = extra_config or {}
if cpu_bytes_to_use is not None:
cfg["cpu_bytes_to_use"] = cpu_bytes_to_use
cfg["spec_name"] = spec_name
if store_threshold > 0:
cfg["store_threshold"] = store_threshold
kv_transfer_config = KVTransferConfig(
kv_connector="OffloadingConnector",
kv_role="kv_both",
kv_connector_extra_config=cfg,
)
return VllmConfig(
scheduler_config=scheduler_config,
model_config=model_config,
cache_config=cache_config,
kv_transfer_config=kv_transfer_config,
device_config=DeviceConfig("cpu"),
)
def _make_layout_vllm_config(
spec_name: str = "CPUOffloadingSpec",
cpu_bytes_to_use: int | None = None,
extra_config: dict | None = None,
tensor_parallel_size: int = 1,
pipeline_parallel_size: int = 1,
prefill_context_parallel_size: int = 1,
decode_context_parallel_size: int = 1,
) -> VllmConfig:
config = MagicMock()
config.cache_config.block_size = 16
config.cache_config.enable_prefix_caching = True
config.cache_config.prefix_match_unit = None
config.cache_config.cache_dtype = torch.float16
config.model_config.model = "test-model"
world_size = (
tensor_parallel_size * pipeline_parallel_size * prefill_context_parallel_size
)
with patch.object(current_platform, "device_count", return_value=world_size):
config.parallel_config = ParallelConfig(
tensor_parallel_size=tensor_parallel_size,
pipeline_parallel_size=pipeline_parallel_size,
prefill_context_parallel_size=prefill_context_parallel_size,
decode_context_parallel_size=decode_context_parallel_size,
)
config.kv_events_config = None
config.use_v2_model_runner = False
connector_extra_config = dict(extra_config or {})
connector_extra_config["spec_name"] = spec_name
if cpu_bytes_to_use is not None:
connector_extra_config["cpu_bytes_to_use"] = cpu_bytes_to_use
config.kv_transfer_config = KVTransferConfig(
kv_connector="OffloadingConnector",
kv_role="kv_both",
kv_connector_extra_config=connector_extra_config,
)
return cast(VllmConfig, config)
def _make_kv_cache_config():
"""Build a minimal KVCacheConfig with one KV cache tensor."""
num_blocks = 16
num_kv_heads = 1
head_size = 1
dtype = torch.float32
page_size = 2 * num_kv_heads * head_size * torch.finfo(dtype).bits // 8
kv_tensor = KVCacheTensor(
size=num_blocks * page_size, shared_by=["layer"], block_stride=0
)
return KVCacheConfig(
num_blocks=num_blocks,
kv_cache_tensors=[kv_tensor],
kv_cache_groups=[
KVCacheGroupSpec(
["layer"],
FullAttentionSpec(
block_size=16,
num_kv_heads=num_kv_heads,
head_size=head_size,
dtype=dtype,
),
)
],
)
def _make_sizing_kv_cache_config(packed: bool) -> KVCacheConfig:
num_blocks = 4
if packed:
kv_cache_tensors = [
KVCacheTensor(
size=64,
shared_by=[layer_name],
block_stride=16,
)
for layer_name in ("layer0", "layer1")
]
else:
kv_cache_tensors = [
KVCacheTensor(size=40, shared_by=["layer0"]),
KVCacheTensor(size=24, shared_by=["layer1"]),
]
return KVCacheConfig(
num_blocks=num_blocks,
kv_cache_tensors=kv_cache_tensors,
kv_cache_groups=[
KVCacheGroupSpec(
["layer0", "layer1"],
FullAttentionSpec(
block_size=16,
num_kv_heads=1,
head_size=1,
dtype=torch.float32,
),
)
],
)
def _make_hybrid_kv_cache_config() -> KVCacheConfig:
return KVCacheConfig(
num_blocks=4,
kv_cache_tensors=[
KVCacheTensor(size=40, shared_by=["full_layer"]),
KVCacheTensor(size=24, shared_by=["mla_layer"]),
],
kv_cache_groups=[
KVCacheGroupSpec(
["full_layer"],
FullAttentionSpec(
block_size=12,
num_kv_heads=1,
head_size=1,
dtype=torch.float32,
),
),
KVCacheGroupSpec(
["mla_layer"],
MLAAttentionSpec(
block_size=16,
num_kv_heads=1,
head_size=576,
dtype=torch.float32,
),
),
],
)
class SingleArgExternalOffloadingSpec(OffloadingSpec):
def get_manager(self) -> OffloadingManager:
raise NotImplementedError
def get_worker(self, kv_caches: CanonicalKVCaches) -> OffloadingWorker:
raise NotImplementedError
# ---------------------------------------------------------------------------
# Pre-registration integrity (CI sentinel)
# ---------------------------------------------------------------------------
def test_pre_registered_specs_can_be_imported():
"""If someone moves cpu/spec.py but forgets to update factory.py, CI fails."""
for name in OffloadingSpecFactory._registry:
cls = OffloadingSpecFactory._registry[name]()
assert issubclass(cls, OffloadingSpec)
def test_cpu_spec_registered():
"""CPUOffloadingSpec is registered and importable."""
cls = OffloadingSpecFactory._registry["CPUOffloadingSpec"]()
assert cls is CPUOffloadingSpec
def test_tiering_spec_registered():
"""TieringOffloadingSpec is registered and importable."""
cls = OffloadingSpecFactory._registry["TieringOffloadingSpec"]()
assert cls is TieringOffloadingSpec
# ---------------------------------------------------------------------------
# Normal path — get_spec_cls
# ---------------------------------------------------------------------------
def test_get_spec_cls_returns_registered_class():
"""Registered spec_name returns correct class."""
config = _make_vllm_config(spec_name="CPUOffloadingSpec")
spec_cls = OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
assert spec_cls is CPUOffloadingSpec
def test_get_spec_cls_default_to_cpu():
"""Default spec_name (absent from config) resolves to CPUOffloadingSpec."""
config = _make_vllm_config(spec_name=None)
config.kv_transfer_config.kv_connector_extra_config.pop("spec_name", None)
spec_cls = OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
assert spec_cls is CPUOffloadingSpec
# ---------------------------------------------------------------------------
# End-to-end — create_spec
# ---------------------------------------------------------------------------
def test_create_cpu_offloading_spec_end_to_end():
"""Full factory → spec construction with real VllmConfig/KVCacheConfig.
Verifies:
- cpu_bytes_to_use validation and num_blocks calculation
- block_size % tokens_per_hash assertion
- spec instance is CPUOffloadingSpec
"""
config = _make_vllm_config(cpu_bytes_to_use=65536)
kv_cache_config = _make_kv_cache_config()
spec = _create_spec(config, kv_cache_config)
assert isinstance(spec, CPUOffloadingSpec)
assert spec.num_blocks > 0
@pytest.mark.parametrize("packed", [False, True])
def test_cpu_spec_sizing_preserves_tensor_layout(packed: bool):
cpu_bytes_to_use = 1920
config = _make_layout_vllm_config(
cpu_bytes_to_use=cpu_bytes_to_use,
extra_config={"block_size": 32},
tensor_parallel_size=3,
pipeline_parallel_size=2,
)
spec = _create_spec(config, _make_sizing_kv_cache_config(packed))
assert isinstance(spec, CPUOffloadingSpec)
assert spec.cpu_page_size_per_worker == 32
assert spec.kv_bytes_per_chunk == 192
assert spec.num_blocks == cpu_bytes_to_use // 192
def test_cpu_spec_rejects_partially_packed_tensor_layout():
config = _make_layout_vllm_config(cpu_bytes_to_use=65536)
kv_cache_config = _make_sizing_kv_cache_config(packed=False)
kv_cache_config.kv_cache_tensors[0].block_stride = 16
with pytest.raises(AssertionError):
_create_spec(config, kv_cache_config)
def test_cpu_spec_zero_blocks_skips_tensor_layout_validation():
config = _make_layout_vllm_config(cpu_bytes_to_use=65536)
kv_cache_config = _make_sizing_kv_cache_config(packed=False)
kv_cache_config.num_blocks = 0
kv_cache_config.kv_cache_tensors[0].block_stride = 16
spec = _create_spec(config, kv_cache_config)
assert isinstance(spec, CPUOffloadingSpec)
assert spec.cpu_page_size_per_worker == 0
assert spec.kv_bytes_per_chunk == 0
assert spec.num_blocks == 0
def test_tiering_spec_aligns_row_size():
alignment = SharedOffloadRegion.BLOCK_SIZE_ALIGNMENT
cpu_bytes_to_use = alignment * 3
config = _make_layout_vllm_config(
spec_name="TieringOffloadingSpec",
cpu_bytes_to_use=cpu_bytes_to_use,
extra_config={"block_size": 32},
tensor_parallel_size=3,
pipeline_parallel_size=2,
)
spec = _create_spec(config, _make_sizing_kv_cache_config(packed=False))
assert isinstance(spec, TieringOffloadingSpec)
assert spec.cpu_page_size_per_worker == 32
assert spec.kv_bytes_per_chunk == alignment
assert spec.num_blocks == cpu_bytes_to_use // alignment
def test_offloading_spec_kv_sharding_ignores_prefill_context_parallel():
config = _make_layout_vllm_config(
cpu_bytes_to_use=65536,
extra_config={"block_size": 64},
prefill_context_parallel_size=2,
)
spec = _create_spec(config, _make_kv_cache_config())
assert spec.tokens_per_block == (16,)
assert spec.tokens_per_hash == 16
assert spec.blocks_per_chunk == 4
def test_offloading_config_preserves_data_parallel_index():
config = _make_layout_vllm_config()
config.parallel_config.data_parallel_index = 2
offloading_config = build_offloading_config(config, _make_kv_cache_config())
assert offloading_config.parallel.data_parallel_index == 2
def test_offloading_spec_resolves_heterogeneous_hybrid_block_sizes():
config = _make_layout_vllm_config(cpu_bytes_to_use=65536)
config.cache_config.block_size = 4
spec = _create_spec(config, _make_hybrid_kv_cache_config())
assert spec.tokens_per_block == (12, 16)
assert spec.tokens_per_hash == 4
assert spec.blocks_per_chunk == 1
def _full_attention_spec(block_size: int = 16) -> FullAttentionSpec:
return FullAttentionSpec(
block_size=block_size, num_kv_heads=4, head_size=128, dtype=torch.float32
)
def _parallelism_agnostic(kv_cache_groups: list[KVCacheGroupSpec]) -> bool:
config = _make_layout_vllm_config()
kv_cache_config = KVCacheConfig(
num_blocks=0, kv_cache_tensors=[], kv_cache_groups=kv_cache_groups
)
offloading_config = build_offloading_config(config, kv_cache_config)
return offloading_config.parallel.is_parallelism_agnostic
def test_parallelism_agnostic_for_single_full_attention_group():
assert _parallelism_agnostic([KVCacheGroupSpec(["l0"], _full_attention_spec())])
@pytest.mark.parametrize(
"kv_cache_groups",
[
# MLA latent KV is replicated per rank, never head-sharded.
[
KVCacheGroupSpec(
["l0"],
MLAAttentionSpec(
block_size=16, num_kv_heads=1, head_size=576, dtype=torch.float32
),
)
],
# Sliding window is not full attention.
[
KVCacheGroupSpec(
["l0"],
SlidingWindowSpec(
block_size=16,
num_kv_heads=4,
head_size=128,
dtype=torch.float32,
sliding_window=128,
),
)
],
# Hybrid model: more than one KV cache group.
[
KVCacheGroupSpec(["l0"], _full_attention_spec()),
KVCacheGroupSpec(["l1"], _full_attention_spec()),
],
],
)
def test_parallelism_agnostic_excluded(kv_cache_groups: list[KVCacheGroupSpec]):
assert not _parallelism_agnostic(kv_cache_groups)
def test_parallelism_agnostic_disabled_on_v2_model_runner():
config = _make_layout_vllm_config()
config.use_v2_model_runner = True
kv_cache_config = KVCacheConfig(
num_blocks=0,
kv_cache_tensors=[],
kv_cache_groups=[KVCacheGroupSpec(["l0"], _full_attention_spec())],
)
offloading_config = build_offloading_config(config, kv_cache_config)
assert not offloading_config.parallel.is_parallelism_agnostic
def test_create_dynamic_spec_receives_translated_config():
config = _make_layout_vllm_config(
spec_name="SingleArgExternalOffloadingSpec",
extra_config={
"spec_module_path": "tests.v1.kv_offload.test_factory",
},
)
kv_cache_config = _make_kv_cache_config()
offloading_config = build_offloading_config(config, kv_cache_config)
spec = OffloadingSpecFactory.create_spec(offloading_config)
assert isinstance(spec, SingleArgExternalOffloadingSpec)
assert spec.config is offloading_config
# ---------------------------------------------------------------------------
# Dynamic import via spec_module_path
# ---------------------------------------------------------------------------
def test_dynamic_load_via_spec_module_path():
"""External spec loaded via spec_module_path.
This is how external projects (e.g., llm-d-kv-cache SharedStorageOffloadingSpec)
integrate with vLLM without being pre-registered in the factory.
The fallback path: registry miss → spec_module_path → importlib.import_module.
"""
config = _make_vllm_config(spec_name="CPUOffloadingSpec")
# Delete from registry to force the dynamic import path
del OffloadingSpecFactory._registry["CPUOffloadingSpec"]
# spec_name not in registry → falls through to spec_module_path
config.kv_transfer_config.kv_connector_extra_config["spec_module_path"] = (
"vllm.v1.kv_offload.cpu.spec"
)
spec_cls = OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
assert spec_cls is CPUOffloadingSpec
# ---------------------------------------------------------------------------
# Error paths
# ---------------------------------------------------------------------------
def test_unregistered_spec_without_module_path_raises():
"""spec_name not in registry + no spec_module_path → ValueError."""
config = _make_vllm_config(spec_name="NonexistentSpec")
with pytest.raises(ValueError, match="Unsupported spec type"):
OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
# create_spec should also fail (calls get_spec_cls internally)
kv_cache_config = _make_kv_cache_config()
with pytest.raises(ValueError, match="Unsupported spec type"):
_create_spec(config, kv_cache_config)
def test_cpu_spec_missing_cpu_bytes_to_use_raises():
"""CPUOffloadingSpec requires cpu_bytes_to_use → Exception."""
config = _make_vllm_config(cpu_bytes_to_use=None)
config.kv_transfer_config.kv_connector_extra_config.pop("cpu_bytes_to_use", None)
kv_cache_config = _make_kv_cache_config()
with pytest.raises(Exception, match="cpu_bytes_to_use must be specified"):
_create_spec(config, kv_cache_config)
def test_duplicate_registration_raises():
"""register_spec with existing name → ValueError."""
with pytest.raises(ValueError, match="is already registered"):
OffloadingSpecFactory.register_spec(
"CPUOffloadingSpec", "some.module", "SomeClass"
)
# ---------------------------------------------------------------------------
# Downstream collaboration — build_metric_definitions
# ---------------------------------------------------------------------------
def test_build_metric_definitions_below_threshold():
"""store_threshold < 2 keeps stores_skipped disabled."""
from vllm.v1.kv_offload.cpu.common import CPUOffloadingMetrics
config = _make_vllm_config(store_threshold=1)
spec_cls = OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
metrics = spec_cls.build_metric_definitions(
config.kv_transfer_config.kv_connector_extra_config
)
assert CPUOffloadingMetrics.STORES_SKIPPED not in metrics
assert CPUOffloadingMetrics.CPU_ALLOCATION_SIZE in metrics
def test_build_metric_definitions_allocation_size_histogram():
"""CPU allocation size is always reported as a histogram."""
from vllm.v1.kv_offload.cpu.common import CPUOffloadingMetrics
config = _make_vllm_config(store_threshold=0)
spec_cls = OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
metrics = spec_cls.build_metric_definitions(
config.kv_transfer_config.kv_connector_extra_config
)
metadata = metrics[CPUOffloadingMetrics.CPU_ALLOCATION_SIZE]
assert isinstance(metadata, OffloadingHistogramMetadata)
assert metadata.buckets == (
1,
4,
16,
64,
256,
1024,
4096,
16384,
65536,
262144,
)
def test_build_metric_definitions_returns_counter_at_threshold():
"""store_threshold >= 2 → returns stores_skipped counter definition."""
from vllm.v1.kv_offload.cpu.common import CPUOffloadingMetrics
config = _make_vllm_config(store_threshold=2)
spec_cls = OffloadingSpecFactory.get_spec_cls(_get_extra_config(config))
metrics = spec_cls.build_metric_definitions(
config.kv_transfer_config.kv_connector_extra_config
)
assert CPUOffloadingMetrics.STORES_SKIPPED in metrics
def test_offloading_spec_accepts_blocks_per_chunk_for_heterogeneous_groups():
config = _make_layout_vllm_config(
cpu_bytes_to_use=65536,
extra_config={"blocks_per_chunk": 2},
)
spec = _create_spec(config, _make_hybrid_kv_cache_config())
assert spec.tokens_per_block == (12, 16)
assert spec.blocks_per_chunk == 2
def test_block_size_and_blocks_per_chunk_are_mutually_exclusive():
config = _make_layout_vllm_config(
cpu_bytes_to_use=65536,
extra_config={
"block_size": 64,
"blocks_per_chunk": 2,
},
)
with pytest.raises(ValueError, match="Specify only one"):
_create_spec(config, _make_kv_cache_config())
def test_blocks_per_chunk_must_be_positive():
config = _make_layout_vllm_config(
cpu_bytes_to_use=65536,
extra_config={
"blocks_per_chunk": 0,
},
)
with pytest.raises(ValueError, match="greater than 0"):
_create_spec(config, _make_kv_cache_config())