Allow for gracefull shutdows

NOTE: This only works on fresh installs. If you want to convert an existing installation to use this feature, you need to update /usr/local/bin/agent.sh on the guest and /storage/agent.ver on the host.

install.sh

@@ -137,6 +137,9 @@ fi
 
 rm -rf $MOUNT
 
+# Store agent version
+echo "2" > "$IMG"/agent.ver
+
 mv -f "$BOOT" "$IMG"/"$BASE".boot.img
 mv -f "$SYSTEM" "$IMG"/"$BASE".system.img
 

power.sh

@@ -5,36 +5,64 @@ set -eu
 
 QEMU_MONPORT=7100
 QEMU_POWERDOWN_TIMEOUT=30
+_QEMU_PID=/run/qemu.pid
+_QEMU_SHUTDOWN_COUNTER=/run/qemu.counter
 
-_graceful_shutdown() {
+# Allows for troubleshooting signals sent to the process
+_trap(){
+    func="$1" ; shift
+    for sig ; do
+        trap "$func $sig" "$sig"
+    done
+}
+
+_graceful_shutdown(){
 
-  local COUNT=0
   local QEMU_MONPORT="${QEMU_MONPORT:-7100}"
   local QEMU_POWERDOWN_TIMEOUT="${QEMU_POWERDOWN_TIMEOUT:-120}"
 
   set +e
-  echo "Trying to shutdown gracefully.."
+  echo "Trapped $1 signal"
+  echo 0 > "${_QEMU_SHUTDOWN_COUNTER}"
 
-  # Send a NMI interrupt which will be detected by the agent
-  # echo 'nmi' | nc -q 1 localhost "${QEMU_MONPORT}">/dev/null 2>&1
-
-  echo 'system_powerdown' | nc -q 1 localhost "${QEMU_MONPORT}">/dev/null 2>&1
-  echo ""
-
-  while echo 'info version'|nc -q 1 localhost "${QEMU_MONPORT:-7100}">/dev/null 2>&1 && [ "${COUNT}" -lt "${QEMU_POWERDOWN_TIMEOUT}" ]; do
-    (( COUNT++ )) || true
-    echo "Shutting down, waiting... (${COUNT}/${QEMU_POWERDOWN_TIMEOUT})"
-    sleep 1
-  done
-
-  if echo 'info version'|nc -q 1 localhost "${QEMU_MONPORT:-7100}">/dev/null 2>&1; then
-    echo "Killing the VM.."
-    echo 'quit' | nc -q 1 localhost "${QEMU_MONPORT}">/dev/null 2>&1 || true
+  FILE="${IMG}/agent.ver"
+  if [ ! -f "$FILE" ]; then
+    AGENT_VERSION="1"
+    echo "$AGENT_VERSION" > "$IMG"/agent.ver
+  else
+    AGENT_VERSION=$(cat "${FILE}")
   fi
 
-  echo "Exiting..."
+  # Don't send the powerdown signal because Synology ignores it
+  # echo 'system_powerdown' | nc -q 1 -w 1 localhost "${QEMU_MONPORT}">/dev/null
+
+  if (($AGENT_VERSION < 2)); then
+     echo "Please update the agent to allow gracefull shutdowns..."
+     pkill -f qemu-system-x86_64
+  else
+     # Send a NMI interrupt which will be detected by the agent
+     echo 'nmi' | nc -q 1 -w 1 localhost "${QEMU_MONPORT}">/dev/null
+  fi
+
+  while [ "$(cat ${_QEMU_SHUTDOWN_COUNTER})" -lt "${QEMU_POWERDOWN_TIMEOUT}" ]; do
+
+    # Increase the counter
+    echo $(($(cat ${_QEMU_SHUTDOWN_COUNTER})+1)) > ${_QEMU_SHUTDOWN_COUNTER}
+
+    # Try to connect to qemu
+    if echo 'info version'| nc -q 1 -w 1 localhost "${QEMU_MONPORT:-7100}">/dev/null; then
+
+      sleep 1
+      #echo "Shutting down, waiting... ($(cat ${_QEMU_SHUTDOWN_COUNTER})/${QEMU_POWERDOWN_TIMEOUT})"
+
+    fi
+  done
+
+  echo 'quit' | nc -q 1 -w 1 localhost "${QEMU_MONPORT}">/dev/null || true
+
+  return
 }
 
-trap _graceful_shutdown SIGINT SIGTERM SIGHUP
+_trap _graceful_shutdown SIGTERM SIGHUP SIGINT SIGABRT SIGQUIT
 
 KVM_MON_OPTS="-monitor telnet:localhost:${QEMU_MONPORT:-7100},server,nowait,nodelay"

run.sh

@@ -36,6 +36,14 @@ fi
 EXTRA_OPTS="-nographic -object rng-random,id=rng0,filename=/dev/urandom -device virtio-rng-pci,rng=rng0 -device virtio-balloon-pci,id=balloon0,bus=pcie.0,addr=0x4"
 ARGS="-m ${RAM_SIZE} -smp ${CPU_CORES} -machine type=q35${KVM_ACC_OPTS} ${EXTRA_OPTS} ${KVM_MON_OPTS} ${KVM_SERIAL_OPTS} ${KVM_NET_OPTS} ${KVM_DISK_OPTS}"
 
-qemu-system-x86_64 ${ARGS} &
+set -m
+(
+  for _SIGNAL in {1..64}; do trap "echo Caught trap ${_SIGNAL} for the QEMU process" "${_SIGNAL}"; done
+  qemu-system-x86_64 ${ARGS} & echo $! > ${_QEMU_PID}
+)
+set +m
 
-wait $!
+# Since we have to start the process with -m, we need to poll every intervall if it's still running
+while [ -d "/proc/$(cat ${_QEMU_PID})"  ]; do
+  sleep 1
+done

serial.sh

@@ -7,7 +7,6 @@
 permanent="DSM"
 serialstart="2000"
 
-IMG="/storage"
 [ ! -d "$IMG" ] && echo "Storage folder (${IMG}) not found!" && exit 69
 
 #If environment variabele not set fall back to file