ci: add vmtest as a reusable workflow

Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>

.github/workflows/test.yml

@@ -1,19 +1,17 @@
 name: libbpf-ci
 
-on: 
+on:
   pull_request:
   push:
   schedule:
     - cron:  '0 18 * * *'
 
-concurrency: 
+concurrency:
   group: ci-test-${{ github.head_ref }}
   cancel-in-progress: true
 
 jobs:
   vmtest:
-    runs-on: ${{ matrix.runs_on }}
-    name: Kernel ${{ matrix.kernel }} on ${{ matrix.arch }} + selftests
     strategy:
       fail-fast: false
       matrix:
@@ -21,15 +19,13 @@ jobs:
           - kernel: 'LATEST'
             runs_on: ubuntu-24.04
             arch: 'x86_64'
-    steps:
-      - uses: actions/checkout@v4
-        name: Checkout
-      - uses: ./.github/actions/setup
-        name: Setup
-      - uses: ./.github/actions/vmtest
-        name: vmtest
-        continue-on-error: false
-        timeout-minutes: 180
-        with:
-          kernel: ${{ matrix.kernel }}
-          arch: ${{ matrix.arch }}
+            llvm-version: '17'
+            pahole: 'master'
+    name: ${{ matrix.kernel }} kernel llvm-${{ matrix.llvm-version }} pahole@${{ matrix.pahole }}
+    uses: ./.github/workflows/vmtest.yml
+    with:
+      runs_on: ${{ matrix.runs_on }}
+      kernel: ${{ matrix.kernel }}
+      arch: ${{ matrix.arch }}
+      llvm-version: ${{ matrix.llvm-version }}
+      pahole: ${{ matrix.pahole }}

.github/workflows/vmtest.yml

@@ -0,0 +1,134 @@
+name: 'Build kernel and selftests/bpf, run selftests via vmtest'
+
+on:
+  workflow_call:
+    inputs:
+      runs_on:
+        required: true
+        default: 'ubuntu-24.04'
+        type: string
+      arch:
+        description: 'what arch to test'
+        required: true
+        default: 'x86_64'
+        type: string
+      kernel:
+        description: 'kernel version or LATEST'
+        required: true
+        default: 'LATEST'
+        type: string
+      pahole:
+        description: 'pahole rev or branch'
+        required: false
+        default: 'master'
+        type: string
+      llvm-version:
+        description: 'llvm version'
+        required: false
+        default: '17'
+        type: string
+jobs:
+  vmtest:
+    runs-on: ${{ inputs.runs_on }}
+    steps:
+
+      - uses: actions/checkout@v4
+
+      - name: Setup environment
+        uses: theihor/libbpf-ci/setup-build-env@run-vmtest-v2
+        with:
+          pahole: ${{ inputs.pahole }}
+          arch: ${{ inputs.arch }}
+          llvm-version: ${{ inputs.llvm-version }}
+
+      - name: Get checkpoint commit
+        shell: bash
+        run: |
+          cat CHECKPOINT-COMMIT
+          echo "CHECKPOINT=$(cat CHECKPOINT-COMMIT)" >> $GITHUB_ENV
+
+      - name: Get kernel source at checkpoint
+        uses: theihor/libbpf-ci/get-linux-source@run-vmtest-v2
+        with:
+          repo: 'https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git'
+          rev: ${{ env.CHECKPOINT }}
+          dest: '${{ github.workspace }}/.kernel'
+
+      - name: Patch kernel source
+        uses: theihor/libbpf-ci/patch-kernel@run-vmtest-v2
+        with:
+          patches-root: '${{ github.workspace }}/ci/diffs'
+          repo-root: '.kernel'
+
+      - name: Configure kernel build
+        shell: bash
+        run: |
+          cd .kernel
+          cat tools/testing/selftests/bpf/config \
+              tools/testing/selftests/bpf/config.${{ inputs.arch }} > .config
+          # this file might or mihgt not exist depending on kernel version
+          cat tools/testing/selftests/bpf/config.vm >> .config || :
+          make olddefconfig && make prepare
+          cd -
+
+      - name: Build kernel image
+        if: ${{ inputs.kernel == 'LATEST' }}
+        shell: bash
+        run: |
+          cd .kernel
+          make -j $((4*$(nproc))) all
+          cp vmlinux ${{ github.workspace }}
+          cd -
+
+      - name: Download prebuilt kernel
+        if: ${{ inputs.kernel != 'LATEST' }}
+        uses: theihor/libbpf-ci/download-vmlinux@run-vmtest-v2
+        with:
+          kernel: ${{ inputs.kernel }}
+          arch: ${{ inputs.arch }}
+
+      - name: Prepare to build selftests
+        shell: bash
+        env:
+          PREPARE_SCRIPT: ${{ github.workspace }}/ci/vmtest/prepare-selftests-build-${{ inputs.kernel }}.sh
+          SELFTESTS_BPF: ${{ github.workspace }}/.kernel/tools/testing/selftests/bpf
+        run: |
+          if [ -f "${PREPARE_SCRIPT}" ]; then
+            bash "${PREPARE_SCRIPT}"
+          fi
+
+      - name: Build selftests/bpf
+        uses: theihor/libbpf-ci/build-selftests@run-vmtest-v2
+        env:
+          MAX_MAKE_JOBS: 32
+          VMLINUX_BTF: ${{ github.workspace }}/vmlinux
+          VMLINUX_H: ${{ inputs.kernel != 'LATEST' && format('{0}/.github/actions/build-selftests/vmlinux.h', github.workspace) || '' }}
+        with:
+          arch: ${{ inputs.arch }}
+          kernel-root: ${{ github.workspace }}/.kernel
+          llvm-version: ${{ inputs.llvm-version }}
+
+      - name: Prepare to run selftests
+        env:
+          ALLOWLIST_FILE: /tmp/allowlist
+          DENYLIST_FILE: /tmp/denylist
+          ARCH: ${{ inputs.arch }}
+          KERNEL: ${{ inputs.kernel }}
+          SELFTESTS_BPF: ${{ github.workspace }}/.kernel/tools/testing/selftests/bpf
+          VMTEST_CONFIGS: ${{ github.workspace }}/ci/vmtest/configs
+        shell: bash
+        run: ${{ github.workspace }}/ci/vmtest/prepare-selftests-run.sh
+
+      - name: Run selftests
+        env:
+          ALLOWLIST_FILE: /tmp/allowlist
+          DENYLIST_FILE: /tmp/denylist
+          KERNEL: ${{ inputs.kernel }}
+          VMLINUX: ${{ github.workspace }}/vmlinux
+        uses: theihor/libbpf-ci/run-vmtest@run-vmtest-v2
+        with:
+          arch: ${{ inputs.arch }}
+          kbuild-output: ${{ github.workspace }}/.kernel
+          kernel-root: ${{ github.workspace }}/.kernel
+          kernel-test: ${{ env.KERNEL_TEST || '' }}
+          vmlinuz: ${{ inputs.arch }}/vmlinuz-${{ inputs.kernel }}