OpenBSD Host How To

[guy]

Seeing as I couldn’t find much help elsewhere, here’s the fruits of my endeavours. This briefly covers how to get an OpenBSD host running a Windows XP VM.

Download and install the qemu package with pkg_add

Create a disk image:

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# qemu-img create -f qcow virtual.hd 4G

OpenBSD Qemu appears to be incapable of booting a physical CDROM, so you’ll have to create a .iso of your install disk. After spending most of a day trying to figure this out using dd and OpenBSD, I gave up and stuck the CD in my FreeBSD workstation, dd’d it, and copied back over to the Open machine.

Networking wasn’t working using the layer 3 tunnelling offered by /dev/tun device, so you’ll need to configure a layer 2 tunnel. The following qemu-ifup script will do this for you:

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#!/bin/sh

guest_gw=”192.168.10.1″
guest_net=”192.168.10.0″
guest_mask=”255.255.255.0″

/sbin/ifconfig em0 alias $qemu_ip netmask $qemu_mask
/sbin/route add $guest_ip $guest_gw $guest_mask
/sbin/ifconfig $1 $guest_gw $guest_mask link0

You'll need to add IP forwarding:

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sysctl -w net.inet.ip.forwarding=1

Update /etc/sysctl.conf whilst you're at it.

NAT can be configured in /etc/pf.conf by adding the following:

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ext_if="em0"
table <qemu-net> persist { 192.168.10.0/24 }
nat on em0 inet from <qemu-net> to any -> em0


Use pfctl to load the pf ruleset:

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# pfctl -f /etc/pf.conf

You can check the NAT configuration of pf using the following:

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# pfctl -sn

Finally, launch your VM with:

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# qemu -m 256 -boot d -cdrom winxp.iso  -hda virtual.hd -n ./qemu-ifup

'256' refers to the RAM made available to the VM. Clearly, if you don't have 256MB to spare, specify less.


Now for the best bit... once you've done all that, built you shiny virtual XP machine and start using it, you'll quickly realise you might be better using a Linux host until we get a BSD port of the Qemu accelerator, KQEMU.

[Edgemaster]

The above is generally correct, but I found the following helpful:
QEmu under OpenBSD seems to be unable to use the cdrom device, no problem, make an image of the disk. For this , I used the readcd program in the cdrtools package:

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# readcd dev=/dev/cd0c f=xppro.iso

I found that the recommended tap network support worked well, with a couple of changes.
Copy the file /usr/local/share/examples/qemu/qemu-ifup to /etc/qemu-ifup
Edit the ETHER=trunk0 line to point to your network interface (eg sis0).

Then starting qemu with:

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# qemu -cdrom xppro.iso -boot d -soundhw all -net tap xp.img

Starts successfully and boots into Windows setup.
However, I find that since I have an upgrade version, I am required to swap disks in the virtual cd drive, this doesn't seem to work too often, since Windows only recognises a disk after several attempts with

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(qemu) switch cdrom win98.iso

A possible solution to this is installing Windows 98 first, then upgrading to XP.

[atlscrog]

I know this is an old thread, but I found it helpful and wanted to add my experience.

The biggest difference is I chose to not assign IP addresses to the tun0 (and tun1, tun2, tunX) interfaces.

Instead, I create a bridge and add them to the bridge along with a real nic.

I then assign an IP address to the interface withing the guest OS that follows my physical network addressing scheme.

For example, I use 192.168.1.1 as my default gateway.

Physical server NICs are assigned an address in a range, such as 192.168.1.20-29, while virtual NICs are assigned a separate range such as 192.168.1.30-39.

Granted, I'm running a very small home network with less than ten machines (including guest OS's), so this simple scheme works for me.

Here is my qemu-ifup script (it is simplified version of the stock script):

#! /bin/sh

_ETHER=nfe0
_BRIDGE=bridge0

# Let the environment over-ride this
[ "$BRIDGE" ] || BRIDGE=${_BRIDGE}
[ "$ETHER" ] || ETHER=${_ETHER}

if test `id -u` -ne 0; then
SUDO=sudo
fi

echo -n " {$1 ($BRIDGE <-> $ETHER)"

# Set the tun device into layer2 mode
$SUDO ifconfig $1 link0 up
$SUDO brconfig $BRIDGE add $1


The bridge is configured by the host machine in /etc/bridgename.bridge0 and includes the following:

add nfe0
up

And that's it. This seems to work well.

[Sunnz]

Just a heads up for those who haven't tried QEMU from the latest ports, they now have a very nice README.OpenBSD that explain exactly how to get networking the way you wanted and some tips on running it under a non-root user.

You can read it on the web: http://www.openbsd.org/cgi-bin/cvsweb/p ... web-markup

That's for 4.5 but the same idea apply to older versions of OpenBSD/ports.