gitlab CI: add support for DRM-backend tests

In order to run DRM-backend tests, a DRM-device is needed. As we
do not necessarily have control of the hardware that is going to
run our tests in GitLab CI, DRM-backend tests were being skipped.
This patch add support to run the tests using VKMS (virtual KMS).
To achieve this, virtualization is needed, as we need to run a
custom kernel during the CI job. We've decided to go with virtme,
as it is simpler to setup and works good for our use case.

Signed-off-by: Leandro Ribeiro <leandro.ribeiro@collabora.com>

.gitlab-ci/debian-install.sh

@@ -2,6 +2,14 @@
 
 set -o xtrace -o errexit
 
+# These get temporary installed for building Linux and then force-removed.
+LINUX_DEV_PKGS="
+	bc
+	bison
+	flex
+	libelf-dev
+"
+
 # These get temporary installed for building Mesa and then force-removed.
 MESA_DEV_PKGS="
 	bison
@@ -74,6 +82,8 @@ apt-get -y --no-install-recommends install \
 	pkg-config \
 	python3-pip \
 	python3-setuptools \
+	qemu-system \
+	sysvinit-core \
 	xwayland \
 	$MESA_RUNTIME_PKGS
 
@@ -85,6 +95,37 @@ pip3 install sphinx==2.1.0 --user
 pip3 install breathe==4.13.0.post0 --user
 pip3 install sphinx_rtd_theme==0.4.3 --user
 
+apt-get -y --no-install-recommends install $LINUX_DEV_PKGS
+git clone --depth=1 --branch=drm-next-2020-06-11-1 https://anongit.freedesktop.org/git/drm/drm.git linux
+cd linux
+make x86_64_defconfig
+make kvmconfig
+./scripts/config --enable CONFIG_DRM_VKMS
+make oldconfig
+make -j8
+cd ..
+mkdir /weston-virtme
+mv linux/arch/x86/boot/bzImage /weston-virtme/bzImage
+mv linux/.config /weston-virtme/.config
+rm -rf linux
+
+# Link to upstream virtme: https://github.com/amluto/virtme
+#
+# The reason why we are using a fork here is that it adds a patch to have the
+# --script-dir command line option. With that we can run scripts that are in a
+# certain folder when virtme starts, which is necessary in our use case.
+#
+# The upstream also has some commands that could help us to reach the same
+# results: --script-sh and --script-exec. Unfornutately they are not completely
+# implemented yet, so we had some trouble to use them and it was becoming
+# hackery.
+#
+git clone https://github.com/ezequielgarcia/virtme
+cd virtme
+git checkout -b snapshot 69e3cb83b3405edc99fcf9611f50012a4f210f78
+./setup.py install
+cd ..
+
 git clone --branch 1.17.0 --depth=1 https://gitlab.freedesktop.org/wayland/wayland
 export MAKEFLAGS="-j4"
 cd wayland
@@ -104,7 +145,6 @@ meson build -Dauto_features=disabled \
 ninja -C build install
 cd ..
 rm -rf mesa
-apt-get -y --autoremove purge $MESA_DEV_PKGS
 
-mkdir -p /tmp/.X11-unix
-chmod 777 /tmp/.X11-unix
+apt-get -y --autoremove purge $LINUX_DEV_PKGS
+apt-get -y --autoremove purge $MESA_DEV_PKGS

.gitlab-ci/virtme-scripts/run-weston-tests.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# folders that are necessary to run Weston tests
+mkdir -p /tmp/tests
+mkdir -p /tmp/.X11-unix
+chmod -R 0700 /tmp
+
+# set environment variables to run Weston tests
+export XDG_RUNTIME_DIR=/tmp/tests
+export WESTON_TEST_SUITE_DRM_DEVICE=card0
+
+# ninja test depends on meson, and meson itself looks for its modules on folder
+# $HOME/.local/lib/pythonX.Y/site-packages (the Python version may differ).
+# virtme starts with HOME=/tmp/roothome, but as we installed meson on user root,
+# meson can not find its modules. So we change the HOME env var to fix that.
+export HOME=/root
+
+# run the tests and save the exit status
+ninja test
+TEST_RES=$?
+
+# create a file to keep the result of this script:
+#   - 0 means the script succeeded
+#   - 1 means the tests failed, so the job itself should fail
+TESTS_RES_PATH=$(pwd)/tests-res.txt
+echo $TEST_RES > $TESTS_RES_PATH
+
+# shutdown virtme
+sync
+poweroff -f