I was wondering about the status of OpenBSD's vmm(4) hypervisor. Is it ready for some limited use, say, testing a port in an i386 VM on an amd64 host?
(TL;DR: nope.) There's little information, so I decided to give it a try after reading the various vmm(4), vm.conf(5), vmd(8), vmctl(8), virtio(4), etc. man pages. First, you need to build a kernel with vmm(4). It is not enabled in GENERIC yet. You also need an up-to-date /dev since vmd opens /dev/vmm and /dev/tap0. Next: Start vmd, create a disk image (can you use a raw partition instead?), spin up a VM with an amd64 bsd.rd kernel I had at hand. # /etc/rc.d/vmd -f start # vmctl create /home/bardioc.img -s 4G # vmctl start -c -k /bsd.rd -m 1G -d /home/bardioc.img -i 1 Something's happening! There's a copyright message. And that's it... I was about to give up when the bsd.rd kernel continued, successfully booted, and allowed to drop me into a (S)hell. Observation: vmd completely hogs one CPU core even if the guest isn't doing anything. Next step: networking. As expected, a vio0 interface showed up inside the VM, but the man pages don't explain how to connect this to the outside. Since I had noticed that vmd opens tap0, I created a bridge on the host and added tap0 and a real interface. I don't know if that's the intended way, but after manually configuring an IP address on vio0, I could ping other machines from the guest. \o/ ping also showed that time was running three times slower in the VM than on the outside. Uh-oh. I deleted the inet configuration from vio0 and started the installer. I got as far as the network configuration, when the guest kernel died with an UVM error--and my patience along with it. So, yeah, interesting but not useful yet. -- Christian "naddy" Weisgerber [email protected]
