<fix>[vm]: verify dest state in migrate flow

[MatheMatrix]

Root Cause

When the hypervisor migration call reports failure, the VM may already be running on the destination host. Treating that response as a hard migration failure can roll back management state even though the data plane migration has completed.

Solution

• In VmMigrateOnHypervisorFlow, check the VM state on the destination host when the hypervisor migration call fails.
• If the destination host reports Running, continue the normal migration flow with chain.next().
• If the destination host reports any other state or the state check fails, keep the original failure path with chain.fail(originalError).
• Keep migration success cleanup on the existing normal flow path.

Test

• git diff --check
• Remote integration case on root@172.20.13.237:/root/zstack-workspace/zstack:
  mvn -q -Dtest=org.zstack.test.integration.kvm.KvmTest -DsubCaseCollectionStrategy=Designated -DcaseFilePath=/tmp/zstac83894-main-cases.txt -DsurefireArgLine="-noverify" test
• Result: Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

sync from gitlab !9902

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Configuration used: Path: http://open.zstack.ai:20001/code-reviews/zstack-cloud.yaml (via .coderabbit.yaml)

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📥 Commits

Reviewing files that changed from the base of the PR and between c394379 and 6736c47.

📒 Files selected for processing (4)

• compute/src/main/java/org/zstack/compute/vm/VmMigrateOnHypervisorFlow.java
• test/src/test/groovy/org/zstack/test/integration/kvm/vm/VmLastHostUuidCase.groovy
• test/src/test/groovy/org/zstack/test/integration/kvm/vm/migrate/MigrateVmFailureCheckTargetHostCase.groovy
• test/src/test/groovy/org/zstack/test/integration/storage/primary/local_nfs/MaintainHostMultiTypePsCase.groovy

🚧 Files skipped from review as they are similar to previous changes (2)

• compute/src/main/java/org/zstack/compute/vm/VmMigrateOnHypervisorFlow.java
• test/src/test/groovy/org/zstack/test/integration/kvm/vm/migrate/MigrateVmFailureCheckTargetHostCase.groovy

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Walkthrough

当迁移请求到目标主机失败时，新增逻辑向目标主机发送 CheckVmStateOnHypervisorMsg 查询 VM 状态；仅当目标主机返回 VM 为 Running 时继续迁移流程，否则以原始迁移错误结束。新增集成测试覆盖回滚与成功场景及相关 mocks。

Changes

VM 迁移故障恢复与状态验证

Layer / File(s)	Summary
迁移故障状态验证实现 compute/src/main/java/org/zstack/compute/vm/VmMigrateOnHypervisorFlow.java	添加 CheckVmStateOnHypervisorMsg/Reply 导入和 CollectionDSL.list 静态导入；在迁移目标服务回调中先判定取消错误，若为迁移失败错误码则调用 checkVmStateOnDestinationHost()；该方法向目的主机查询 VM 状态并仅在返回 Running 时调用 chain.next()，否则以原迁移错误失败。
集成测试框架与 Mock 设置 test/src/test/groovy/org/zstack/test/integration/kvm/vm/migrate/MigrateVmFailureCheckTargetHostCase.groovy (1-130, 178-213), test/src/test/groovy/org/zstack/test/integration/storage/primary/local_nfs/MaintainHostMultiTypePsCase.groovy	新增 MigrateVmFailureCheckTargetHostCase 测试类，构建 EnvSpec 并实现 mockMigrateVmFailure()（模拟 KVM 迁移 API 返回错误）与 mockVmState()（拦截 CheckVmStateOnHypervisorMsg，按入参返回各主机 VM 状态并收集 checkedHosts）；在另一路测试中新增 KVM_VM_CHECK_STATE 模拟器以返回特定 VM 的 Shutdown/Running 状态。
测试场景：回滚与成功迁移 test/src/test/groovy/org/zstack/test/integration/kvm/vm/migrate/MigrateVmFailureCheckTargetHostCase.groovy (131-176)	两个用例：当目标主机报告 VM 非 Running 时断言迁移回滚且 VM 保留在源主机；当目标主机报告 VM Running 时断言迁移成功并更新 hostUuid，并验证 checkedHosts 内容。

Sequence Diagram

sequenceDiagram
  participant Flow as VmMigrateOnHypervisorFlow
  participant CloudBus as CloudBus
  participant DestHost as 目标主机

  Flow->>DestHost: MigrateVmOnHypervisorMsg (迁移请求)
  DestHost-->>Flow: 错误响应（迁移失败）
  Flow->>CloudBus: CheckVmStateOnHypervisorMsg (请求 vmInstanceUuids)
  CloudBus->>DestHost: 转发查询请求
  DestHost-->>CloudBus: 返回 VM 状态映射
  CloudBus-->>Flow: CheckVmStateOnHypervisorReply (states)
  alt states[vmUuid] == Running
    Flow->>Flow: chain.next() (继续迁移流程)
  else
    Flow->>Flow: chain.fail(migrateError) (以原错误结束)
  end

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Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

诗歌

迁移路途遇波折，兔子不急忙，
先问彼岸可安康，若已运行便放行，
若非彼方心未定，归还故里莫慌张，
模拟与测皆相随，检查名单一一详，
代码走通测试好，兔儿鼓掌喜洋洋。 🐰✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	标题完全关联主要变更：检查目标主机上的VM状态以处理迁移失败场景，符合 [scope]: 格式且不超过72字符。
Description check	✅ Passed	描述与变更集相关，明确说明根本原因、解决方案、测试方法和结果，与代码变更内容一致。
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

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• Commit unit tests in branch sync/shan.wu/fix/5.5.22/ZSTAC-83894

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[coderabbitai]

Actionable comments posted: 1

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Verify each finding against current code. Fix only still-valid issues, skip the
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Inline comments:
In `@compute/src/main/java/org/zstack/compute/vm/VmMigrateOnHypervisorFlow.java`:
- Around line 87-89: The code reads the VM state without null checks which can
NPE when states is absent; update the block in VmMigrateOnHypervisorFlow to
null-check CheckVmStateOnHypervisorReply#getStates() and the looked-up state
(r.getStates() and r.getStates().get(spec.getVmInventory().getUuid())) before
comparing to VmInstanceState.Running.toString(), and if either is null treat it
as a failure path and invoke chain.fail(migrateError) (keep the existing
migrateError handling and logging).

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Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: http://open.zstack.ai:20001/code-reviews/zstack-cloud.yaml (via .coderabbit.yaml)

Review profile: CHILL

Plan: Pro

Run ID: 2bc0dd2d-1b7e-4ffb-b185-e5bba819b173

📥 Commits

Reviewing files that changed from the base of the PR and between f83c595 and 1e49d9d.

📒 Files selected for processing (2)

• compute/src/main/java/org/zstack/compute/vm/VmMigrateOnHypervisorFlow.java
• test/src/test/groovy/org/zstack/test/integration/kvm/vm/migrate/MigrateVmFailureCheckTargetHostCase.groovy

[zstack-robot-2]

Comment on compute/src/main/java/org/zstack/compute/vm/VmMigrateOnHypervisorFlow.java:

Comment from shan.wu:

Fixed in c39437913e.

CheckVmStateOnHypervisorReply#getStates() is now checked for null/empty before reading the VM state. Missing state data falls back to chain.fail(migrateError), preserving the original migration error path.

Validation:

• git diff --check
• Remote integration case: Tests run: 1, Failures: 0, Errors: 0, Skipped: 0