NetBSD NVMM & QEMU: No ipv4 address for guest

sar3aphagus01

Hello, I'm using a VPS at a data center, it is running on kvm itself, I installed NetBSD 10.1 on it because I prefer this setup to the default debian linux that the provider offers, however, I find that virtualization is a bit trickier to set up on BSDs but it is just as performant as kvm. I have a need to set up an isolated guest OS because the host is currently running a Tor relay which I don't want any traffic to get intermingled with other services running on the server. First I tried haiku OS guest, mainly to test the qemu setup and nvmm performance but the graphics are so slow it was nearly unusable and no ipv4 address was assigned through the bridged connection (Haiku OS still does not have ipv6 support in 2026), then I installed a trisquel linux console system meant for use for a server and everything works except the ipv4 address, It does not appear to be possible to request it via dhcp from inside it, and I cannot use ipv6 only. the npf firewall is not blocking it and dhcpd is running on the host. here is the setup used for trisquel linux: qemu-system-x86_64 -hda trisquellinux-gnu.qcow2 -cdrom trisquel-netinst_11.0.1_amd64.iso -m 770M --accel nvmm -vnc :0 -netdev tap,id=tap0,ifname=tap0,script=no -device virtio-net-pci,netdev=tap0
Tried something similar with FreeBSD 15 guest to see if this was more compatible with BSD guests but similiar to linux only ipv6 worked. until the internet and its applications modernize I can't use ipv6 only. This is probably a simple oversight but want to see if anyone else had similar issues using this stack.

rvp

sar3aphagus01 Are you trying to run QEMU with -accel nvmm within a NetBSD instance running on KVM itself?

This is what I use for bare metal virtualization:

$ cat ~/tmp/qemu/qemu.sh
#!/bin/sh

# [ $(id -u) -eq 0 ] || exit 1
cd ~rvp/tmp/qemu || exit 1
modstat | fgrep -q nvmm || sudo sh -c 'umask 022; modload nvmm'
test -f netbsd.qcow2 || qemu-img create -f qcow2 netbsd.qcow2 4G
qemu-system-x86_64 -accel nvmm -machine q35 -cpu host -smp 2 -m 2G \
        -bios /usr/pkg/share/ovmf/OVMFX64.fd \
        -display sdl,gl=es -vga std \
        -usb -device usb-mouse,bus=usb-bus.0 \
        -drive file=netbsd.qcow2,if=none,id=hd0 -device virtio-blk-pci,drive=hd0 \
        -audiodev oss,id=oss,out.dev=/dev/audio,in.dev=/dev/audio -device ac97,audiodev=oss \
        -object rng-random,filename=/dev/urandom,id=viornd0 -device virtio-rng-pci,rng=viornd0 \
        -netdev tap,ifname=tap0,script=no,downscript=no,id=vioif0 -device virtio-net-pci,netdev=vioif0 \
        "$@"
        # -nographic \
        # -display none -serial mon:stdio \
        # -display none -vga vmware \
        # -display curses \
        # -cdrom /tmp/NetBSD-9.4_STABLE-amd64.iso \
rm -fv *.core
$

IPv4 works fine using this. (In fact, I disable IPv6 everywhere because my provider doesn't seem to supply any IPv6 address.)

sar3aphagus01

Thanks. For some reason the BIOS firmware file is needed by some OSes but not others. If it is simple console system it doesn't seem to need it. This problem was caused by IPV4 addresses being behind a NAT probably on the KVM hypervisor of my NetBSD VPS, IPv6 doesn't get affected by NAT so that's why it worked. There doesn't seem to be a performance drop in the nested virtualization I'm trying to use. Resource usage is great. I could probably run 3 to 5 small VMs on a host with 4GB of memory.