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XEN machine on NetBSD 6.1.5

Important steps to have xen dom0 with HVM running:
(works also on raid1 disk mirror)

• Install xenkernel4.1 and xentools4.1
  and unpack then kernel to /.
  


• Downoad xen dom0 kernel from ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-6.1.5/amd64/binary/kernel/netbsd-XEN3_DOM0.gz
  or compile a kernel with dom0 from sources and place it to /.
  
  
• Modify bootloader by adding one line for xen
$ cat /boot.cfg
menu=Boot normally:rndseed /var/db/entropy-file;boot netbsd
menu=Boot Xen:load /netbsd.dom0 console=pc;multiboot /xen dom0_mem=1024M noreboot
menu=Boot single user:rndseed /var/db/entropy-file;boot netbsd -s
menu=Disable ACPI:rndseed /var/db/entropy-file;boot netbsd -2
menu=Disable ACPI and SMP:rndseed /var/db/entropy-file;boot netbsd -12
menu=Drop to boot prompt:prompt
default=1
timeout=5
clear=1


• Create a xen domU machine config file.
  
$ cat /usr/pkg/etc/xen/win7.cfg
name = "win7"
memory = "880"
# for windows we need HVM kind of xen - complete virtualization kernel = "hvmloader"
builder = 'hvm'
vcpus=1
pae=1
acpi=1
apic=1
# for some reason this is the best working network card vif = [ 'type=ioemu, mac=00:2d:ff:00:0d:03, 'bridge=bridge0' , model=e1000']
#specify disks, for me the cd0 did not work so I had to create an image of DVD #like this:# dd if=/dev/cd0a of=install_win7.iso disk = [ 'file:/home/robin/win.img,hda,w', 'file:/home/robin/install_win7.iso,hdc:cdrom,r' ]
usbdevice = 'tablet' #this makes mouse pointer more friendly
boot="adc"
# sequence of devices to boot domU sdl=0 #the default command line console will not appear
opengl=1
vnc=1 #this lets you open a vnc console
stdvga=0
soundhw='sb16' # this should bring up the sound
on_reboot = 'destroy' #This is good for possible debugging
on_crash = 'destroy'

  
• Networking for the Xen guest
  
  The simple way is to create bridge and connect Xen as a regular pc directly to the network: Provided your network card is wm0, create this bridge config file
$ cat /etc/ifconfig.bridge0
create
!brconfig $int add wm0 up
The harder, but network independent way is to nat over tap0. You have to do several system changes
  1. run dhcp server for the machines
  2. run nat with ipf or pf (pf needs to recompile kernel)
  That all can be done as follows:
  
  Configure tap0 before bridge0. Put these lines in /etc/rc.conf: auto_ifconfig=NO
net_interfaces="`/sbin/ifconfig -l` tap0 bridge0"

Create a tap0 interface and assign it e.g., 192.168.0.1. Put this in /etc/rc.conf:
  ifconfig_tap0="192.168.0.1 netmask 255.255.0.0"

Create /etc/ifconfig.bridge0 with this contents:
  create
!brconfig $int add tap0 up

  In order to allow IP routing between the tap interfaces connected to the bridge, append this to /etc/sysctl.conf:
  net.inet.ip.forwarding=1
  Probably setup a DHCP server for assigning IP addresses to emulated systems. The right interface to use for the DHCP server is tap0.
  
  If you wish emulated systems to access the Internet, setup a NAT, e.g., put
  ext_if=XXX
ext_addr=X.Y.Z.T
nat on $ext_if from 192.168.0.0/16 to any -> $ext_addr
in /etc/pf.conf and set pf=YES in /etc/rc.conf.
  Replace XXX with the host Ethernet interface of choice. Replace X.Y.Z.T with its IP address.
  
  
• Running Xen commands
# xm list   -    shows running guests and host VMs
# xm create /usr/pkg/etc/xen/win7.cfg   -   starts a VM configured in the file
# xm vcpus-list   -   shows usage of CPUs and virtual CPUs
# xm shutdown -F win7   -    acpi shutdown
# xm destroy win7   -    forced manual shutdown, may result in data loss