e2e: add a test that hotplugs and hotremoves CXL memory (CXL-3)

test/e2e/memory.test-suite/memory-policy/n4-cxl/kernel_config.var.sh

@@ -0,0 +1 @@
+qemu-cxl-kernel.config

test/e2e/memory.test-suite/memory-policy/n4-cxl/kernel_getsource.var.sh

@@ -0,0 +1 @@
+vanilla

test/e2e/memory.test-suite/memory-policy/n4-cxl/test00-build-cxl-kernel/code.var.sh

@@ -0,0 +1,65 @@
+# Test following features in the test framework.
+# - Create a virtual machine with hotpluggable CXL memories (none attached at boot time).
+# - Building and installing a custom kernel with custom configuration.
+# - Using udev-monitor for detecting hardware configuration changes.
+# - Hotplugging, onlining, offlining and hotremoving CXL memories.
+
+if [[ "$distro" != *"fedora"* ]]; then
+    echo "SKIP: this test runs only on fedora"
+    exit 0
+fi
+
+vm-kernel-pkgs-install
+
+vm-command "command -v cxl || dnf install -y /usr/bin/cxl numactl"
+
+vm-command "command -v udev-monitor" || {
+    HOST_UDEV_MONITOR=$OUTPUT_DIR/udev-monitor
+
+    [ -f "$HOST_UDEV_MONITOR" ] || \
+        GOARCH=amd64 go build -o "$HOST_UDEV_MONITOR" "${TEST_DIR%%/test/e2e/*}/scripts/udev-monitor/udev-monitor.go" || \
+        error "failed to build $HOST_UDEV_MONITOR"
+
+    vm-put-file "$HOST_UDEV_MONITOR" "/usr/local/bin/udev-monitor"
+}
+
+echo "launching udev-monitor in the background"
+vm-command-q "udev-monitor 2>&1 | tee udev-monitor.output" &
+
+sleep 2
+echo "next: hotplug CXL"
+vm-cxl-hotplug cxl_memdev0
+
+sleep 2
+vm-command "set -x
+           sh -c 'grep . /sys/devices/system/node/{online,possible} /sys/devices/system/memory/auto_online_blocks'
+           echo online_movable > /sys/devices/system/memory/auto_online_blocks
+           sh -c 'grep 0 /sys/devices/system/memory/memory*/online'
+           sleep 1
+           cxl enable-memdev mem0
+           sleep 1
+           cxl create-region -t ram -d decoder0.0 -m mem0
+           sleep 1
+           cxl enable-region region0
+           sleep 1
+           sh -c 'grep . /sys/devices/system/node/{online,possible}'
+           sh -c 'grep 0 /sys/devices/system/memory/memory*/online'
+           sh -c 'for f in /sys/devices/system/memory/memory*/online; do echo 1 > \$f; done'
+           sleep 1
+           sh -c 'grep 0 /sys/devices/system/memory/memory*/online'
+           "
+sleep 2
+echo "hotplugging more memories"
+sleep 2
+vm-cxl-hotplug cxl_memdev3
+vm-cxl-hotplug cxl_memdev1
+vm-cxl-hotplug cxl_memdev2
+sleep 5
+vm-command "cxl list"
+
+echo "hotremoving single memory"
+vm-cxl-hotremove cxl_memdev2
+sleep 5
+vm-command "cxl list"
+
+vm-command "pkill udev-monitor"

test/e2e/memory.test-suite/memory-policy/n4-cxl/topology.var.json

@@ -0,0 +1,7 @@
+[
+    {"mem": "4G", "threads":2, "cores": 2, "nodes": 1, "packages": 2},
+    {"cxl": [
+	      [{"switch": [{"mem": "256M", "present": false}, {"mem": "256M", "present": false}]}],
+	      [{"switch": [{"mem": "256M", "present": false}, {"mem": "256M", "present": false}]}]
+	    ]}
+]