Qemu was released in 2003 and kvm in 2006 according to Wikipedia.
also: qemu tries to support all kinds of hardware and tons of features. bhyve is slick and does it's job for 95% of standard usecases. bhyves codebase is much smaller, and thus bears far fewer risks and technical debt.
summerofcode.withgoogle.com
.... Keep at it 
sh bench.sh # run all tests
sh bench.sh cpu # run individual test#!/bin/sh
#
# bench.sh — QEMU+bhyve VMM performance benchmark suite
#
# Reproduces the benchmark table from the FreeBSD QEMU+bhyve/vmm project.
# Run identically on the host (native) and inside the guest VM, then compare.
#
# Usage:
# sh bench.sh # run all benchmarks
# sh bench.sh cpu # run only CPU integer test
# sh bench.sh syscall # run only syscall overhead test
# sh bench.sh fork # run only process creation test
# sh bench.sh mem_dd # run only dd memory bandwidth test
# sh bench.sh mem_sysbench # run only sysbench memory test (requires sysbench)
# sh bench.sh disk # run only disk I/O test
# sh bench.sh all # run all (default)
#
# Requirements:
# - C compiler (cc or gcc)
# - dd (standard)
# - sysbench (optional, for mem_sysbench; install: pkg install sysbench)
# - /tmp with at least 256 MB free (for disk test)
#
# The script compiles small C test programs on the fly into /tmp, runs them,
# and prints results. No installation needed.
#
# Project: QEMU + bhyve/vmm accelerator on FreeBSD
# Author: marietto (with Claude Code)
# Date: 2026-06-09 (original benchmarks), 2026-06-23 (script)
# License: Public domain / CC0
#
set -e
TMPDIR="${TMPDIR:-/tmp}"
BENCH_DIR="${TMPDIR}/vmm-bench-$$"
mkdir -p "$BENCH_DIR"
# Find a C compiler
CC=""
for c in cc clang gcc; do
if command -v "$c" >/dev/null 2>&1; then CC="$c"; break; fi
done
if [ -z "$CC" ]; then
echo "ERROR: no C compiler found (tried cc, clang, gcc)" >&2
exit 1
fi
cleanup() {
rm -rf "$BENCH_DIR"
}
trap cleanup EXIT
# ── Helpers ──────────────────────────────────────────────────────────────────
print_header() {
echo ""
echo "================================================================================"
echo " VMM Benchmark Suite — $(date '+%Y-%m-%d %H:%M:%S')"
echo " Host: $(uname -srm)"
printf " CPU: "
sysctl -n hw.model 2>/dev/null || { cat /proc/cpuinfo 2>/dev/null | grep 'model name' | head -1 | sed 's/.*: //' || echo "unknown"; }
printf " RAM: "
if sysctl -n hw.physmem >/dev/null 2>&1; then
echo "$(( $(sysctl -n hw.physmem) / 1073741824 )) GB"
elif [ -f /proc/meminfo ]; then
awk '/MemTotal/{printf "%d GB\n", $2/1048576}' /proc/meminfo
else
echo "unknown"
fi
echo "================================================================================"
echo ""
}
# ── 1. CPU integer: 100M integer operations ──────────────────────────────────
bench_cpu() {
echo "── CPU integer (100M int ops) ──"
cat > "$BENCH_DIR/cpu_int.c" << 'CEOF'
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main(void)
{
struct timespec t0, t1;
volatile int x = 0;
int i;
clock_gettime(CLOCK_MONOTONIC, &t0);
for (i = 0; i < 100000000; i++)
x = x + i * 3 - i / 2 + 1;
clock_gettime(CLOCK_MONOTONIC, &t1);
long ms = (t1.tv_sec - t0.tv_sec) * 1000L
+ (t1.tv_nsec - t0.tv_nsec) / 1000000L;
/* machine-readable on stderr, human-readable on stdout */
fprintf(stderr, "%ld\n", ms);
printf(" 100M int ops: %ld ms\n", ms);
return 0;
}
CEOF
$CC -O2 -o "$BENCH_DIR/cpu_int" "$BENCH_DIR/cpu_int.c"
# warm up
"$BENCH_DIR/cpu_int" > /dev/null 2>/dev/null
# actual run (best of 3)
best=999999
for run in 1 2 3; do
ms=$("$BENCH_DIR/cpu_int" 2>&1 >/dev/null)
if [ "$ms" -lt "$best" ]; then best=$ms; fi
done
echo " 100M int ops: ${best} ms (best of 3 runs)"
echo ""
}
# ── 2. Syscall overhead: getpid() x 1M ──────────────────────────────────────
bench_syscall() {
echo "── Syscall overhead (getpid() x 1M) ──"
cat > "$BENCH_DIR/syscall_bench.c" << 'CEOF'
#include <stdio.h>
#include <time.h>
#include <unistd.h>
int main(void)
{
struct timespec t0, t1;
int i;
volatile pid_t p;
clock_gettime(CLOCK_MONOTONIC, &t0);
for (i = 0; i < 1000000; i++)
p = getpid();
clock_gettime(CLOCK_MONOTONIC, &t1);
long ns = (t1.tv_sec - t0.tv_sec) * 1000000000L
+ (t1.tv_nsec - t0.tv_nsec);
long ns_per = ns / 1000000;
fprintf(stderr, "%ld\n", ns_per);
printf(" getpid() x 1M: %ld ns/call\n", ns_per);
(void)p;
return 0;
}
CEOF
$CC -O2 -o "$BENCH_DIR/syscall_bench" "$BENCH_DIR/syscall_bench.c"
"$BENCH_DIR/syscall_bench" > /dev/null 2>/dev/null
best=999999
for run in 1 2 3; do
val=$("$BENCH_DIR/syscall_bench" 2>&1 >/dev/null)
if [ "$val" -lt "$best" ]; then best=$val; fi
done
echo " getpid() x 1M: ${best} ns/call (best of 3)"
echo ""
}
# ── 3. Process creation: fork()+wait x 200 ──────────────────────────────────
bench_fork() {
echo "── Process creation (fork()+wait x 200) ──"
cat > "$BENCH_DIR/fork_bench.c" << 'CEOF'
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <sys/wait.h>
int main(void)
{
struct timespec t0, t1;
int i, status;
clock_gettime(CLOCK_MONOTONIC, &t0);
for (i = 0; i < 200; i++) {
pid_t p = fork();
if (p < 0) { perror("fork"); exit(1); }
if (p == 0) _exit(0);
waitpid(p, &status, 0);
}
clock_gettime(CLOCK_MONOTONIC, &t1);
long us = (t1.tv_sec - t0.tv_sec) * 1000000L
+ (t1.tv_nsec - t0.tv_nsec) / 1000L;
fprintf(stderr, "%ld\n", us);
printf(" fork()+wait x 200: %ld us (%ld us/iter)\n", us, us / 200);
return 0;
}
CEOF
$CC -O2 -o "$BENCH_DIR/fork_bench" "$BENCH_DIR/fork_bench.c"
"$BENCH_DIR/fork_bench" > /dev/null 2>/dev/null
best=999999999
for run in 1 2 3; do
val=$("$BENCH_DIR/fork_bench" 2>&1 >/dev/null)
if [ "$val" -lt "$best" ]; then best=$val; fi
done
echo " fork()+wait x 200: ${best} us (best of 3)"
echo ""
}
# ── 4. Memory bandwidth: dd /dev/zero -> /dev/null ───────────────────────────
bench_mem_dd() {
echo "── Memory bandwidth (dd /dev/zero -> /dev/null, 256 MB) ──"
# warm up
dd if=/dev/zero of=/dev/null bs=1m count=256 2>/dev/null
for run in 1 2 3; do
# dd reports speed on stderr
bw=$(dd if=/dev/zero of=/dev/null bs=1m count=256 2>&1 | tail -1)
echo " run $run: $bw"
done
echo ""
}
# ── 5. Memory bandwidth: sysbench ────────────────────────────────────────────
bench_mem_sysbench() {
echo "── Memory bandwidth (sysbench, block 1M, 20 GB total) ──"
if ! command -v sysbench >/dev/null 2>&1; then
echo " SKIPPED: sysbench not installed (pkg install sysbench)"
echo ""
return
fi
for op in read write; do
for threads in 1 8; do
result=$(sysbench memory \
--memory-block-size=1M \
--memory-total-size=20G \
--memory-oper=$op \
--threads=$threads \
run 2>/dev/null | grep 'transferred' | grep -oE '[0-9]+\.[0-9]+' | tail -1)
printf " %-6s %d thread(s): %s MiB/s\n" "$op" "$threads" "${result:-N/A}"
done
done
echo ""
}
# ── 6. Disk I/O: sequential write+fsync and cached read ─────────────────────
bench_disk() {
echo "── Disk I/O (128 MB, /tmp) ──"
TF="$TMPDIR/vmm-bench-disktest-$$"
# Sequential write + fsync
cat > "$BENCH_DIR/disk_write.c" << 'CEOF'
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
const char *path = (argc > 1) ? argv[1] : "/tmp/vmm-bench-diskfile";
int fd = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0600);
if (fd < 0) { perror("open"); return 1; }
/* 128 MB in 1 MB chunks */
char *buf = malloc(1048576);
memset(buf, 0x55, 1048576);
struct timespec t0, t1;
clock_gettime(CLOCK_MONOTONIC, &t0);
for (int i = 0; i < 128; i++) {
if (write(fd, buf, 1048576) != 1048576) { perror("write"); return 1; }
fsync(fd);
}
clock_gettime(CLOCK_MONOTONIC, &t1);
close(fd);
free(buf);
long us = (t1.tv_sec - t0.tv_sec) * 1000000L
+ (t1.tv_nsec - t0.tv_nsec) / 1000L;
double mb_s = 128.0 * 1000000.0 / (double)us;
printf(" Seq write+fsync (128 MB): %.1f MB/s (%ld ms)\n", mb_s, us / 1000);
return 0;
}
CEOF
$CC -O2 -o "$BENCH_DIR/disk_write" "$BENCH_DIR/disk_write.c"
"$BENCH_DIR/disk_write" "$TF"
# Sequential read (cached) — file is now hot in page cache
cat > "$BENCH_DIR/disk_read.c" << 'CEOF'
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
const char *path = (argc > 1) ? argv[1] : "/tmp/vmm-bench-diskfile";
int fd = open(path, O_RDONLY);
if (fd < 0) { perror("open"); return 1; }
char *buf = malloc(1048576);
struct timespec t0, t1;
ssize_t n;
/* warm: read once to fill page cache */
while ((n = read(fd, buf, 1048576)) > 0) {}
lseek(fd, 0, SEEK_SET);
clock_gettime(CLOCK_MONOTONIC, &t0);
while ((n = read(fd, buf, 1048576)) > 0) {}
clock_gettime(CLOCK_MONOTONIC, &t1);
close(fd);
free(buf);
long us = (t1.tv_sec - t0.tv_sec) * 1000000L
+ (t1.tv_nsec - t0.tv_nsec) / 1000L;
double gb_s = 128.0 / 1024.0 * 1000000.0 / (double)us;
printf(" Seq read cached (128 MB): %.1f GB/s (%ld ms)\n", gb_s, us / 1000);
return 0;
}
CEOF
$CC -O2 -o "$BENCH_DIR/disk_read" "$BENCH_DIR/disk_read.c"
"$BENCH_DIR/disk_read" "$TF"
rm -f "$TF"
echo ""
}
# ── Main ─────────────────────────────────────────────────────────────────────
run_all=0
run_cpu=0
run_syscall=0
run_fork=0
run_mem_dd=0
run_mem_sysbench=0
run_disk=0
if [ $# -eq 0 ] || [ "$1" = "all" ]; then
run_all=1
else
for arg in "$@"; do
case "$arg" in
cpu) run_cpu=1 ;;
syscall) run_syscall=1 ;;
fork) run_fork=1 ;;
mem_dd) run_mem_dd=1 ;;
mem_sysbench) run_mem_sysbench=1 ;;
disk) run_disk=1 ;;
all) run_all=1 ;;
*) echo "Unknown benchmark: $arg"; exit 1 ;;
esac
done
fi
print_header
if [ $run_all -eq 1 ] || [ $run_cpu -eq 1 ]; then bench_cpu; fi
if [ $run_all -eq 1 ] || [ $run_syscall -eq 1 ]; then bench_syscall; fi
if [ $run_all -eq 1 ] || [ $run_fork -eq 1 ]; then bench_fork; fi
if [ $run_all -eq 1 ] || [ $run_mem_dd -eq 1 ]; then bench_mem_dd; fi
if [ $run_all -eq 1 ] || [ $run_mem_sysbench -eq 1 ]; then bench_mem_sysbench; fi
if [ $run_all -eq 1 ] || [ $run_disk -eq 1 ]; then bench_disk; fi
echo "================================================================================"
echo " Done. Run this script on both host and guest, then compare results."
echo "================================================================================"- ef8c9f048a — FreeBSD 15.0 guest support (boots to login)
- e21f571e56 — fix keyboard during the loader menu and FreeBSD login
- 5d1963528c — fix CR4.FSGSBASE per fork() (sshd, pkg are working)
- ba623258c0 — runtime fixes for FreeBSD 15.0 and Debian
- ee4e6b12b6 — SMP8 support
- d963e50e9a + bc208686df — GPU passthrough NVIDIA
- fbfa8be673 — LAPIC IRR scrubbing for MSI passthrough