Re: running NetBSD under UTM (with QEMU) on macOS....

[RVP <rvp%SDF.ORG@localhost>]

On Thu, 27 Feb 2025, Greg A. Woods wrote:

> So I reverted to IDE, which has been reliable, but seems about 1/3 the
> speed of the SCSI emulation.

Don't use any emulated HW at all, is my recommendation. Use virtio wherever
you can, instead.

> So, my main question is with the device emulations available in QEMU,
> which do people have the most luck and performance with?

I use this for QEMU on Ubuntu:

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

set -eu
cd ~/tmp/qemu
test -f netbsd.qcow2 || qemu-img create -f qcow2 netbsd.qcow2 10G
kvm -enable-kvm -machine ubuntu-q35,accel=kvm -device intel-iommu -m 4g \
        -cpu host -smp cpus=4,cores=2,threads=2 -bios /usr/share/ovmf/OVMF.fd \
        -drive file=netbsd.qcow2,if=none,id=hd0 -device virtio-blk-pci,drive=hd0 \
        -object rng-random,filename=/dev/urandom,id=viornd0 -device virtio-rng-pci,rng=viornd0 \
        -netdev user,id=net0,hostfwd=tcp::5555-:22 -device virtio-net-pci,netdev=net0 \
        "$@"
        # -device virtio-gpu OR -device virtio-vga \
        # -nographic -cdrom /tmp/NetBSD-10.1_STABLE-amd64.iso \
$
```

Since you're on -HEAD, also look at the MICROVM kernel:

https://github.com/NetBSD/src/blob/trunk/sys/arch/amd64/conf/MICROVM#L11

-RVP