adding cold boot time benchmark measurement script

docs/benchmark.md

@@ -0,0 +1,105 @@
+# Benchmark Tool
+
+The benchmark script measures VM boot time by capturing a boot completion message via Unix socket.
+
+## Usage
+
+```bash
+./scripts/benchmark.sh [OPTIONS] [KERNEL_PATH] [DRIVE_PATH]
+```
+
+### Options
+
+- `-q, --quiet`: Quiet mode - outputs only the boot time in seconds (useful for scripting)
+- `-c, --cores NUM`: Number of CPU cores to allocate to the VM (default: 1)
+- `-m, --mem SIZE`: Memory size in MB to allocate to the VM (default: 256)
+
+### Arguments
+
+- `KERNEL_PATH`: Path to the kernel file (default: `kernels/netbsd-SMOL`)
+- `DRIVE_PATH`: Path to the disk image (default: `images/benchmark-amd64.img`)
+
+## Examples
+
+### Basic Usage (Verbose Mode)
+
+```bash
+$ ./scripts/benchmark.sh
+Kernel: kernels/netbsd-SMOL
+Drive: images/benchmark-amd64.img
+Starting VM at Thu Oct 30 09:45:13 PM CET 2025
+Socket ready: measure_boot.sock
+VM PID: 35983
+Waiting for boot message...
+
+=========================================
+Boot time: 0.143655123 seconds
+=========================================
+
+Message received:
+BOOT_COMPLETE
+```
+
+### Quiet Mode
+
+```bash
+$ ./scripts/benchmark.sh -q
+0.140307116
+```
+
+### Custom Kernel and Drive
+
+```bash
+# Custom kernel only (uses default drive)
+$ ./scripts/benchmark.sh kernels/custom-kernel
+
+# Custom kernel and drive
+$ ./scripts/benchmark.sh kernels/custom-kernel images/custom.img
+
+# Quiet mode with custom paths
+$ ./scripts/benchmark.sh -q kernels/custom-kernel images/custom.img
+
+# With custom CPU and RAM
+$ ./scripts/benchmark.sh -c 2 -m 512
+
+# Combining options
+$ ./scripts/benchmark.sh -q -c 4 -m 1024 kernels/custom-kernel
+```
+
+### Scripting Examples
+
+```bash
+# Run multiple benchmarks and calculate average
+total=0
+runs=10
+for i in $(seq 1 $runs); do
+  time=$(./scripts/benchmark.sh -q)
+  total=$(echo "$total + $time" | bc)
+  echo "Run $i: $time seconds"
+done
+avg=$(echo "scale=9; $total / $runs" | bc)
+echo "Average: $avg seconds"
+
+# Compare two different configurations
+echo "Configuration A:"
+time_a=$(./scripts/benchmark.sh -q kernels/netbsd-SMOL images/config-a.img)
+echo "Configuration B:"
+time_b=$(./scripts/benchmark.sh -q kernels/netbsd-SMOL images/config-b.img)
+diff=$(echo "$time_b - $time_a" | bc)
+echo "Difference: $diff seconds"
+```
+
+## Requirements
+
+- `qemu` with KVM support
+- `socat` for Unix socket communication
+- `bc` for floating-point arithmetic
+
+## How It Works
+
+1. Creates a Unix socket for communication with the VM
+2. Starts a `socat` server listening on the socket
+3. Launches QEMU with the specified kernel and drive
+4. The VM sends "BOOT_COMPLETE" message via virtio console to the socket
+5. Measures the time between VM launch and message receipt
+6. Cleans up processes and temporary files

scripts/benchmark.sh

@@ -0,0 +1,56 @@
+#!/bin/sh
+
+# Define log function based on quiet flag
+log() {
+    [ "$QUIET" != "true" ] && echo "$@"
+}
+
+setup_benchmark() {
+    SOCKET="measure_boot.sock"
+    FIFO="/tmp/boot_fifo_$$"
+
+    rm -f "./$SOCKET" "$FIFO"
+    mkfifo "$FIFO"
+
+    # Start socat server FIRST - listening and ready before QEMU starts
+    timeout 10 socat UNIX-LISTEN:"./$SOCKET" - 2>/dev/null > "$FIFO" &
+    SOCAT_PID=$!
+
+    log "Socket ready: $SOCKET"
+
+    START_TIME=$(date +%s.%N)
+    log "Starting VM at $(date)"
+
+    # Export variables for parent script
+    export BENCHMARK_SOCKET="$SOCKET"
+    export BENCHMARK_FIFO="$FIFO"
+    export BENCHMARK_START_TIME="$START_TIME"
+    export BENCHMARK_SOCAT_PID="$SOCAT_PID"
+}
+
+finish_benchmark() {
+    # Read from FIFO (blocks until data arrives)
+    head -1 < "$BENCHMARK_FIFO" > /dev/null
+
+    END_TIME=$(date +%s.%N)
+    BOOT_TIME=$(printf "%.9f" $(echo "$END_TIME - $BENCHMARK_START_TIME" | bc))
+
+    if [ "$QUIET" = "true" ]; then
+        echo "$BOOT_TIME"
+    else
+        log ""
+        log "========================================="
+        log "Boot time: ${BOOT_TIME} seconds"
+        log "========================================="
+        log ""
+    fi
+
+    # Force kill QEMU and cleanup the socket
+    kill $BENCHMARK_SOCAT_PID $BENCHMARK_VM_PID 2>/dev/null || true
+    rm -f "./$BENCHMARK_SOCKET" "$BENCHMARK_FIFO"
+}
+
+benchmark_extra_chardev() {
+    echo "-chardev socket,path=${BENCHMARK_SOCKET},server=off,id=measure0 \
+-device virtconsole,chardev=measure0,name=measure0"
+}

service/benchmark/etc/rc

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+. /etc/include/basicrc
+
+cd /dev && /bin/sh /etc/MAKEDEV ttyVI01
+
+# Send boot complete immediately
+echo "BOOT_COMPLETE" > /dev/ttyVI01
+
+ksh
+
+. /etc/include/shutdown

service/benchmark/etc/sysctl.conf

@@ -0,0 +1,2 @@
+# this takes ages
+net.inet6.ip6.dad_count=0

startnb.sh

@@ -6,7 +6,7 @@ usage()
 Usage:	${0##*/} -f conffile | -k kernel -i image [-c CPUs] [-m memory]
 	[-a kernel parameters] [-r root disk] [-h drive2] [-p port]
 	[-t tcp serial port] [-w path] [-x qemu extra args]
-	[-b] [-n] [-s] [-d] [-v] [-u]
+	[-b] [-n] [-s] [-d] [-v] [-u] [-B] [-q]
 
 	Boot a microvm
 	-f conffile	vm config file
@@ -27,6 +27,8 @@ Usage:	${0##*/} -f conffile | -k kernel -i image [-c CPUs] [-m memory]
 	-d		daemonize
 	-v		verbose
 	-u		non-colorful output
+	-B		benchmark mode (measure boot time)
+	-q		quiet mode (with -B, output only boot time)
 	-h		this help
 _USAGE_
 	# as per https://www.qemu.org/docs/master/system/invocation.html
@@ -40,7 +42,7 @@ if pgrep VirtualBoxVM >/dev/null 2>&1; then
 	exit 1
 fi
 
-options="f:k:a:p:i:m:n:c:r:l:p:uw:x:t:hbdsv"
+options="f:k:a:p:i:m:n:c:r:l:p:uw:x:t:hbdsvBq"
 
 export CHOUPI=y
 
@@ -52,6 +54,7 @@ do
 	case $opt in
 	a) append="$OPTARG";;
 	b) bridgenet=yes;;
+	B) BENCHMARK=yes;;
 	c) cores="$OPTARG";;
 	d) DAEMON=yes;;
 	# first load vm config file
@@ -69,6 +72,7 @@ do
 	m) mem="$OPTARG";;
 	n) max_ports=$(($OPTARG + 1));;
 	p) hostfwd=$OPTARG;;
+	q) QUIET=true;;
 	r) root="$OPTARG";;
 	s) sharerw=yes;;
 	t) serial_port=$OPTARG;;
@@ -82,6 +86,13 @@ done
 
 . service/common/choupi
 
+# Benchmark mode setup
+if [ -n "$BENCHMARK" ]; then
+	. scripts/benchmark.sh
+	setup_benchmark
+	max_ports=2
+fi
+
 # envvars override
 kernel=${kernel:-$KERNEL}
 img=${img:-$NBIMG}
@@ -223,6 +234,8 @@ if [ -n "$max_ports" ]; then
 		echo "host socket ${v}: ${sockpath}"
 	done
 fi
+# Benchmark mode: add measurement socket
+[ -n "$BENCHMARK" ] && viosock="$viosock $(benchmark_extra_chardev)"
 # QMP is available
 [ -n "${qmp_port}" ] && extra="$extra -qmp tcp:localhost:${qmp_port},server,wait=off"
 
@@ -238,4 +251,11 @@ cmd="${QEMU} -smp $cores \
 
 [ -n "$VERBOSE" ] && echo "$cmd" && exit
 
-eval $cmd
+if [ -n "$BENCHMARK" ]; then
+	eval $cmd > /dev/null 2>&1 &
+	BENCHMARK_VM_PID=$!
+	export BENCHMARK_VM_PID
+	finish_benchmark
+else
+	eval $cmd
+fi