[PATCH for-7.0] gitlab-ci: Add cirrus-ci based tests for NetBSD and OpenBSD

[Thomas Huth <thuth@redhat.com>]

Cirrus-CI provides KVM in their Linux containers, so we can also run
our VM-based NetBSD and OpenBSD build jobs there.
Since the VM installation might take a while, we only run the "help"
target on the first invocation to avoid timeouts, and then only check
the build during the next run, once the base image has been cached.
For the the build tests, we also only use very a limited set of target
CPUs since compiling in these VMs is not very fast (especially the
build on OpenBSD seems to be incredibly slow).
For the time being, the jobs are also marked as manually only, since
this double-indirect setup (with the cirrus-run script and VMs in
the Cirrus-CI containers) might fail more often than the other jobs.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 If you're interested, you can see some runs here:
 NetBSD: https://gitlab.com/thuth/qemu/-/jobs/1865965079
 OpenBSD: https://gitlab.com/thuth/qemu/-/jobs/1866116634

 .gitlab-ci.d/cirrus.yml           | 35 +++++++++++++++++++++++++++++++
 .gitlab-ci.d/cirrus/kvm-build.yml | 31 +++++++++++++++++++++++++++
 2 files changed, 66 insertions(+)
 create mode 100644 .gitlab-ci.d/cirrus/kvm-build.yml

diff --git a/.gitlab-ci.d/cirrus.yml b/.gitlab-ci.d/cirrus.yml
index 90bbe9f8ff..f2d4c0ca4f 100644
--- a/.gitlab-ci.d/cirrus.yml
+++ b/.gitlab-ci.d/cirrus.yml
@@ -64,3 +64,38 @@ x64-macos-11-base-build:
     PATH_EXTRA: /usr/local/opt/ccache/libexec:/usr/local/opt/gettext/bin
     PKG_CONFIG_PATH: /usr/local/opt/curl/lib/pkgconfig:/usr/local/opt/ncurses/lib/pkgconfig:/usr/local/opt/readline/lib/pkgconfig
     TEST_TARGETS: check-unit check-block check-qapi-schema check-softfloat check-qtest-x86_64
+
+
+# The following jobs run VM-based tests via KVM on a Linux-based Cirrus-CI job
+.cirrus_kvm_job:
+  stage: build
+  image: registry.gitlab.com/libvirt/libvirt-ci/cirrus-run:master
+  needs: []
+  timeout: 80m
+  allow_failure: true
+  script:
+    - sed -e "s|[@]CI_REPOSITORY_URL@|$CI_REPOSITORY_URL|g"
+          -e "s|[@]CI_COMMIT_REF_NAME@|$CI_COMMIT_REF_NAME|g"
+          -e "s|[@]CI_COMMIT_SHA@|$CI_COMMIT_SHA|g"
+          -e "s|[@]NAME@|$NAME|g"
+          -e "s|[@]CONFIGURE_ARGS@|$CONFIGURE_ARGS|g"
+          -e "s|[@]TEST_TARGETS@|$TEST_TARGETS|g"
+      <.gitlab-ci.d/cirrus/kvm-build.yml >.gitlab-ci.d/cirrus/$NAME.yml
+    - cat .gitlab-ci.d/cirrus/$NAME.yml
+    - cirrus-run -v --show-build-log always .gitlab-ci.d/cirrus/$NAME.yml
+  rules:
+    - when: manual
+
+x86-netbsd:
+  extends: .cirrus_kvm_job
+  variables:
+    NAME: netbsd
+    CONFIGURE_ARGS: --target-list=x86_64-softmmu,ppc64-softmmu,aarch64-softmmu
+    TEST_TARGETS: check
+
+x86-openbsd:
+  extends: .cirrus_kvm_job
+  variables:
+    NAME: openbsd
+    CONFIGURE_ARGS: --target-list=i386-softmmu,riscv64-softmmu,mips64-softmmu
+    TEST_TARGETS: check
diff --git a/.gitlab-ci.d/cirrus/kvm-build.yml b/.gitlab-ci.d/cirrus/kvm-build.yml
new file mode 100644
index 0000000000..4334fabf39
--- /dev/null
+++ b/.gitlab-ci.d/cirrus/kvm-build.yml
@@ -0,0 +1,31 @@
+container:
+  image: fedora:35
+  cpu: 4
+  memory: 8Gb
+  kvm: true
+
+env:
+  CIRRUS_CLONE_DEPTH: 1
+  CI_REPOSITORY_URL: "@CI_REPOSITORY_URL@"
+  CI_COMMIT_REF_NAME: "@CI_COMMIT_REF_NAME@"
+  CI_COMMIT_SHA: "@CI_COMMIT_SHA@"
+
+@NAME@_task:
+  @NAME@_vm_cache:
+    folder: $HOME/.cache/qemu-vm
+  install_script:
+    - dnf update -y
+    - dnf install -y git make openssh-clients qemu-img qemu-system-x86 wget
+  clone_script:
+    - git clone --depth 100 "$CI_REPOSITORY_URL" .
+    - git fetch origin "$CI_COMMIT_REF_NAME"
+    - git reset --hard "$CI_COMMIT_SHA"
+  build_script:
+    - if [ -f $HOME/.cache/qemu-vm/images/@NAME@.img ]; then
+        make vm-build-@NAME@ J=$(getconf _NPROCESSORS_ONLN)
+          EXTRA_CONFIGURE_OPTS="@CONFIGURE_ARGS@"
+          BUILD_TARGET="@TEST_TARGETS@" ;
+      else
+        make vm-build-@NAME@ J=$(getconf _NPROCESSORS_ONLN) BUILD_TARGET=help
+          EXTRA_CONFIGURE_OPTS="--disable-system --disable-user --disable-tools" ;
+      fi
-- 
2.27.0