Current status

Summary of the current status of QEMU hosted on a NetBSD host.

What works?

Quick summary:

Standard features matrix

Elementary features for NetBSD are probably well supported.

Name Description NetBSD status
python Python programming language should work
smbd Samba net/samba, untested
git GIT VCS should work
debug should work
sanitizers ASan, UBSan, ASan headers should work
sanitizers Fibers Asan headers with fibers Futue GCC/Clang should work
stack-protector Stack protector works
audio oss OSS audio backend should work
audio sdl SDL audio backend should work
coroutine ucontext should work
coroutine sigaltstack should work
coroutine windows N/A, Windows specific
slirp User networking works
tcg-interpreter Tiny Code Generator should work
malloc-trim GNU malloc(3) optimization N/A, Linux specific
gcov Test Coverage Program should work
gprof GNU profiling should work
profiler should work

Optional feature matrix

Additional features support various extensions, most of them are a matter of using the emulator with a 3rd party and are OS independent.

Part of features require OS specific extensions.

Name Description NetBSD status
system all system emulation targets works
user supported user emulation targets broken
linux-user all linux usermode emulation targets N/A
bsd-user all BSD usermode emulation targets broken (FreeBSD ships local patches)
docs build documentation should work
guest-agent build the QEMU Guest Agent unknown, probably broken
guest-agent-msi build guest agent Windows MSI installation package unknown, probably broken
pie Position Independent Executables should work
modules QEMU modules support (not kernel modules) unknown, should work
debug-tcg TCG debugging (default is disabled) should work
debug-info debugging information should work
sparse sparse checker should work
gnutls GNUTLS cryptography support should work
nettle nettle cryptography support should work
gcrypt libgcrypt cryptography support should work
sdl SDL UI should work
--with-sdlabi select preferred SDL ABI 1.2 or 2.0 should work, not imporant
gtk gtk UI should work
--with-gtkabi select preferred GTK ABI 2.0 or 3.0 should work, not important
vte vte support for the gtk UI should work
curses curses UI works with native NetBSD 8.0 curses(3)
vnc VNC UI support should work
vnc-sasl SASL encryption for VNC server should work
vnc-jpeg JPEG lossy compression for VNC server should work
vnc-png PNG compression for VNC server should work
cocoa Cocoa UI (Mac OS X only) N/A, Darwin specific
virtfs VirtFS probably broken
mpath Multipath persistent reservation passthrough unknown, problably not supported
xen xen backend driver support unknown
xen-pci-passthrough PCI passthrough support for Xen unknown, probably not supported
brlapi BrlAPI (Braile) unknown, should work
curl curl connectivity should work
membarrier membarrier system call (for Linux 4.14+ or Windows) not supported
fdt fdt device tree unknown, should work
bluez bluez stack connectivity unknown
kvm KVM acceleration support N/A , Linux specific kernel APIs required in userland
hax HAX acceleration support mostly works
hvf Hypervisor.framework acceleration support not ported, Darwin specific
whpx Windows Hypervisor Platform acceleration support N/A
rdma Enable RDMA-based migration and PVRDMA support unknown, probably not supported
vde support for vde network probably not supported and Linux specific as of today
netmap support for netmap network not supported (FreeBSD specific?)
linux-aio Linux AIO support not supported, Linux specific
cap-ng libcap-ng support not supported, Linux specific
attr attr and xattr support N/A, Linux specific ?
vhost-net vhost-net acceleration support not supported
vhost-crypto vhost-crypto acceleration support not supported
spice spice unknown, probably not supported
rbd rados block device (rbd) unknown
libiscsi iscsi support unknown
libnfs nfs support unknown
smartcard smartcard support (libcacard) unknown
libusb libusb (for usb passthrough) unknown
live-block-migration Block migration in the main migration stream unknown
usb-redir usb network redirection support unknown
lzo support of lzo compression library should work
snappy support of snappy compression library should work
bzip2 support of bzip2 compression library should work
seccomp seccomp support Linux specific (?)
coroutine-pool coroutine freelist (better performance) unknown
glusterfs GlusterFS backend unknown
tpm TPM support unknown
libssh2 ssh block device support should work
numa libnuma support not ported
libxml2 for Parallels image format should work
tcmalloc tcmalloc support should work
jemalloc jemalloc support works
replication replication support not ported, N/A ?, Linux specific
vhost-vsock virtio sockets device support not ported
opengl opengl support unknown
virglrenderer virgl rendering support unknown
xfsctl xfsctl support N/A / not ported
qom-cast-debug cast debugging support unknown
tools build qemu-io, qemu-nbd and qemu-image tools works (userland nbd only)
vxhs Veritas HyperScale vDisk backend support N/A ?
crypto-afalg Linux AF_ALG crypto backend driver N/A / not ported
vhost-user vhost-user support not ported
capstone capstone disassembler support should work

External features

  1. HQEMU

HQEMU is a retargetable and multi-threaded dynamic binary translator on multicores. It integrates QEMU and LLVM as its building blocks. The translator in the enhanced QEMU acts as a fast translator with low translation overhead. The optimization-intensive LLVM optimizer running on separate threads dynamically improves code for higher performance. With the hybrid QEMU+LLVM approach, HQEMU can achieve low translation overhead and good translated code quality. HQEMU supports process-level emulation and full-system virtualization. It provides translation modes of running the QEMU translator and LLVM optimizer in one process, or running the LLVM optimizer as a stand-alone optimization server (version 0.13.0).


  1. DPDK

DPDK is a set of libraries and drivers for fast packet processing.


  1. The ultimate CPU emulator

Unicorn is a lightweight multi-platform, multi-architecture CPU emulator framework.


Prioritized tasks

  1. Upstream remaining local pkgsrc patches, mostly (old?) NetBSD and SmartOS related ones.

  2. Make QEMU PaX MPROTECT safe.

  3. Develop NetBSD USER emulation, attempt to either share the code with FreeBSD (bsd-user, old broken, downstream patches) or with Linux (linux-user, recent, actively maintained). Preferred approach is to share as much code with linux-user as possible, regardless of the state of bsd-user.


HAXM is a cross-platform hardware-assisted virtualization engine (hypervisor), widely used as an accelerator for Android Emulator and QEMU. It has always supported running on Windows and macOS, and has been ported to other host operating systems as well, such as Linux and NetBSD.

HAXM runs as a kernel-mode driver on the host operating system, and provides a KVM-like interface to user space, thereby enabling applications like QEMU to utilize the hardware virtualization capabilities built into modern Intel CPUs, namely Intel Virtualization Technology.

More information on the porting process is available on The NetBSD blog:


A tutorial (outdated) by an early user of the support:


NetBSD/amd64 is the only supported host of the package, but it shouldn't be difficult to expand it to Darwin, Windows and Linux if there would be users and maintainers for these OSes.

NetBSD as host version 8.0 and HEAD (8.99.3x) tested. The minimal version that could work in theory is 6.x, but everything prior 8.0 is untested.

There is no longer need to keep a patched host kernel.

There is need to keep at least a copy of syssrc in /usr/src(/sys).

Guests known to work:

Other OSes are either broken or untested.


  1. Install emulators/haxm from pkgsrc
  2. Install emulators/qemu 3.1.0nb5 or newer from pkgsrc
  3. Use auxiliary scripts for HAXM (superuser privileges needed)
  4. Append HAXM option to qemu (qemu --accel hax)

Auxiliary scripts in the HAXM package:

Optionally grant access to the HAXM device nodes to user(s):