replace virtme with vimto

vimto is a lightweight wrapper around qemu with the sole purpose of
executing Go unit tests. Use it instead of virtme, which has not
had a reliable upstream for a while.

Signed-off-by: Lorenz Bauer <oss@lmb.io>
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>

.github/workflows/ci.yml

@@ -7,8 +7,8 @@ on:
 
 env:
   TMPDIR: /tmp
-  CI_MAX_KERNEL_VERSION: '6.6'
   CI_MIN_CLANG_VERSION: '11'
+  CGO_ENABLED: '0'
   go_version: '~1.21'
   prev_go_version: '~1.20'
   # This needs to match whatever Netlify supports.
@@ -108,7 +108,16 @@ jobs:
     runs-on: ubuntu-latest-4cores-16gb
     needs: build-and-lint
     timeout-minutes: 10
+    env:
+      CI_KERNEL_SELFTESTS: '/usr/src/linux/tools/testing/selftests/bpf'
     steps:
+      - name: Set up Go 1.21
+        uses: actions/setup-go@v4
+        with:
+          go-version: '~1.21'
+
+      - run: go install lmb.io/vimto@latest
+
       - uses: actions/checkout@v3
 
       - name: Set up Go
@@ -117,14 +126,14 @@ jobs:
           go-version: '${{ env.prev_go_version }}'
 
       - run: go install gotest.tools/gotestsum@v1.8.1
-      - run: sudo pip3 install https://github.com/amluto/virtme/archive/beb85146cd91de37ae455eccb6ab67c393e6e290.zip
       - run: sudo apt-get update && sudo apt-get install -y --no-install-recommends qemu-system-x86
+      - run: sudo chmod 0666 /dev/kvm
 
       - name: Test
-        run: gotestsum --raw-command --ignore-non-json-output-lines --junitfile junit.xml -- ./run-tests.sh $CI_MAX_KERNEL_VERSION -short -count 1 -json ./...
+        run: gotestsum --raw-command --ignore-non-json-output-lines --junitfile junit.xml -- go test -exec vimto -vm.kernel ghcr.io/cilium/ci-kernels:stable-selftests -short -count 1 -json ./...
 
       - name: Benchmark
-        run: go test -exec sudo -short -run '^$' -bench . -benchtime=1x ./...
+        run: go test -exec vimto -vm.kernel ghcr.io/cilium/ci-kernels:stable-selftests -short -run '^$' -bench . -benchtime=1x ./...
 
       - name: Upload Test Results
         if: always()
@@ -144,7 +153,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: '${{ env.prev_go_version }}'
+          go-version: '${{ env.go_version }}'
 
       - run: go install gotest.tools/gotestsum@v1.8.1
 
@@ -173,23 +182,33 @@ jobs:
     timeout-minutes: 10
     strategy:
       matrix:
-        version: ["6.7", "6.1", "5.15", "5.10", "5.4", "4.19", "4.14", "4.9"]
+        tag:
+          - "stable"
+          - "6.6"
+          - "6.1"
+          - "5.15"
+          - "5.10"
+          - "5.4"
+          - "4.19"
+          - "4.14"
+          - "4.9"
     env:
-      KERNEL_VERSION: "${{ matrix.version }}"
+      CI_MAX_KERNEL_VERSION: '6.6'
     steps:
       - uses: actions/checkout@v3
 
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version: '${{ env.prev_go_version }}'
+          go-version: '${{ env.go_version }}'
 
       - run: go install gotest.tools/gotestsum@v1.8.1
-      - run: sudo pip3 install https://github.com/amluto/virtme/archive/beb85146cd91de37ae455eccb6ab67c393e6e290.zip
+      - run: go install lmb.io/vimto@latest
       - run: sudo apt-get update && sudo apt-get install -y --no-install-recommends qemu-system-x86
+      - run: sudo chmod 0666 /dev/kvm
 
       - name: Test
-        run: gotestsum --raw-command --ignore-non-json-output-lines --junitfile junit.xml -- ./run-tests.sh $KERNEL_VERSION -short -count 1 -json ./...
+        run: gotestsum --raw-command --ignore-non-json-output-lines --junitfile junit.xml -- go test -exec vimto -vm.kernel ghcr.io/cilium/ci-kernels:${{ matrix.tag }} -short -count 1 -json ./...
 
       - name: Upload Test Results
         if: always()

.vimto.toml

@@ -0,0 +1,12 @@
+kernel="ghcr.io/cilium/ci-kernels:stable"
+smp="cpus=1,maxcpus=2"
+memory="768M"
+user="root"
+setup=[
+  "mount -t cgroup2 -o nosuid,noexec,nodev cgroup2 /sys/fs/cgroup",
+  "/bin/sh -c '! modprobe bpf_testmod'",
+  "dmesg --clear",
+]
+teardown=[
+  "dmesg --read-clear",
+]

docs/ebpf/contributing/index.md

@@ -9,30 +9,25 @@ a better understanding of the high-level goals.
 Many of the tests require privileges to set resource limits and load eBPF code.
 The easiest way to obtain these is to run the tests with `sudo`.
 
-To test the current package with your local kernel you can simply run:
-```
-go test -exec sudo ./...
-```
-
-To test the current package with a different kernel version you can use the [run-tests.sh] script.
-It requires [virtme], qemu and docker to be installed.
-Unfortunately virtme is not well maintained at the moment, so we recommend installing
-a known working version:
+Run all tests with the following command:
 
 ```shell-session
-pip3 install https://github.com/amluto/virtme/archive/beb85146cd91de37ae455eccb6ab67c393e6e290.zip
+go test -exec sudo ./...
 ```
 
-Once you have the dependencies you can run all tests on a different kernel:
+To test the current package with a different kernel version you can use [vimto].
+Once you have installed `vimto` and its dependencies you can run all tests on a
+different kernel:
 
 ```shell-session
-./run-tests.sh 5.4
+go test -exec vimto ./...
 ```
 
-Or run a subset of tests:
+Use one of the [precompiled kernels](https://github.com/cilium/ci-kernels/pkgs/container/ci-kernels/versions) like so:
+
 
 ```shell-session
-./run-tests.sh 5.4 -run TCX ./link
+go test -exec vimto -vm.kernel ghcr.io/cilium/ci-kernels:mainline ./...
 ```
 
 ## Regenerating testdata and source code
@@ -87,8 +82,7 @@ you as a code owner. Please create an issue in the repository.
     * Have ["Admin"][permissions] role
     * CODEOWNERS of last resort
 
-[virtme]: https://github.com/amluto/virtme
-[run-tests.sh]: https://github.com/cilium/ebpf/blob/main/run-tests.sh
+[vimto]: https://github.com/lmb/vimto
 [permissions]: https://docs.github.com/en/organizations/managing-user-access-to-your-organizations-repositories/repository-roles-for-an-organization#permissions-for-each-role
 [ebpf-go-contributors]: https://github.com/orgs/cilium/teams/ebpf-go-contributors/members
 [ebpf-go-reviewers]: https://github.com/orgs/cilium/teams/ebpf-go-reviewers/members

elf_reader_test.go

@@ -938,7 +938,7 @@ func TestIPRoute2Compat(t *testing.T) {
 }
 
 var (
-	elfPath    = flag.String("elfs", os.Getenv("KERNEL_SELFTESTS"), "`Path` containing libbpf-compatible ELFs (defaults to $KERNEL_SELFTESTS)")
+	elfPath    = flag.String("elfs", os.Getenv("CI_KERNEL_SELFTESTS"), "`Path` containing libbpf-compatible ELFs (defaults to $CI_KERNEL_SELFTESTS)")
 	elfPattern = flag.String("elf-pattern", "*.o", "Glob `pattern` for object files that should be tested")
 )
 

internal/version_test.go

@@ -52,7 +52,7 @@ func TestCurrentKernelVersion(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if evStr := os.Getenv("KERNEL_VERSION"); evStr != "" {
+	if evStr := os.Getenv("CI_KERNEL_VERSION"); evStr != "" {
 		ev, err := NewVersion(evStr)
 		if err != nil {
 			t.Fatal(err)