updating netbsd-7 with kvm

KVM commandline (on host):
 screen -S qemu06 /usr/local/bin/qemu-system-x86_64 -enable-kvm -cpu host -smp 4,cores=4,maxcpus=8 -m 2048 -net nic,model=e1000 -net tap,ifname=tap5,script=no -hda /home/random/qemu/x86/n7cde/cde.vdi -nographic
====
build command (inside VM):
time ./build.sh -x -r -j4 release iso-image

=====
make iso-image started at:  Tue Jan 19 18:56:17 AKST 2016
make iso-image finished at: Tue Jan 19 18:57:22 AKST 2016
===> Successful make iso-image
===> build.sh ended:      Tue Jan 19 18:57:22 AKST 2016
===> Summary of results:
         build.sh command:    ./build.sh -x -r -j4 release iso-image
         build.sh started:    Tue Jan 19 17:11:58 AKST 2016
         NetBSD version:      7.0.0_PATCH
         MACHINE:             amd64
         MACHINE_ARCH:        x86_64
         Build platform:      NetBSD 7.0 amd64
         HOST_SH:             /bin/sh
         No $TOOLDIR/bin/nbmake, needs building.
         Bootstrapping nbmake
         MAKECONF file:       /etc/mk.conf
         TOOLDIR path:        /usr/src/obj/tooldir.NetBSD-7.0-amd64
         DESTDIR path:        /usr/src/obj/destdir.amd64
         RELEASEDIR path:     /usr/src/obj/releasedir
         Removing /usr/src/obj/tooldir.NetBSD-7.0-amd64
         Removing /usr/src/obj/destdir.amd64
         Created /usr/src/obj/tooldir.NetBSD-7.0-amd64/bin/nbmake
         Updated makewrapper: /usr/src/obj/tooldir.NetBSD-7.0-amd64/bin/nbmake-amd64  
         Successful make release
         Successful make iso-image
         build.sh ended:      Tue Jan 19 18:57:22 AKST 2016
===> .
     6324.10 real     12894.15 user      4787.03 sys

Qemu bridging sorted

My original idea was to put a script in $HOME/bin which would start tap interfaces on demand.

That ran into snags when the echo 1 >/proc commands would give me permission errors.

Then I had the idea -make everything permanent and throw it all into /etc/rc.local.

Not the most elegant solution -but at least now I have six guarenteed tap interfaces to work with!

here's the code to put in /etc/rc.local (warning, make sure your distro supports /etc/rc.local..many newer ones may not);

 echo 1 > /proc/sys/net/ipv4/ip_forward
 echo 1 > /proc/sys/net/ipv4/conf/wlan0/proxy_arp

for x in {0..5}
 do
  tunctl -u random 
  sudo ip link set tap$x up
  echo 1 > /proc/sys/net/ipv4/conf/tap$x/proxy_arp
  route add -host 192.168.200.2$x dev tap$x
done

exit 0
===
Rebooted, works for me! So far, at least.

My next problem to work out involves figuring out how to kill headless qemu sessions (x86 doesn't give any output when done with -nographic).

struggling with qemu bridging

I think I almost have this figured out.

I read these two blogs:
https://shanetomlinson.com/2009/bridging-a-wireless-card-in-kvmqemu/
and
http://blog.bodhizazen.net/linux/bridge-wireless-cards/

Basically I'm creating a new route on a new interface (tap*) and connecting through that.


router=192.168.200.1
Host=192.168.200.100

So, I install everything I need and might need

sudo apt-get install uml-utils bridge-utils

from bodhi's blog;

C : Tap. We do not assign a ip address to the tap, rather we assign a route on the host. This route will become the ip address of the guest.
route = 192.168.0.20

This is important to note.
So far it seems that what that means is that for each virtual machine you want to make, you'll need to make a new tun device and add it's IP to the host machine's routing table.

On the host after each reboot the tun device(s) ..one for each vm.. need to be remade.

So, the important numbers for my configuration;
router: 192.168.200.1
host:192.168.200.100
tap0:192.168.200.20
tap1:192.168.200.21
and so on (tap2 .22;tap3 .23 etc)

So we take the following steps to make a tap device
sudo -s
tunctl -u $USERNAME (note; use your actual username, not "$USERNAME")
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/conf/wlan0/proxy_arp
echo 1 > /proc/sys/net/ipv4/conf/tap0/proxy_arp
ip link set tap0 up
route add -host 192.168.200.20 dev tap0

Then in the virtual machine you can use 192.168.200.20 as the IP, 192.168.200.100 as the gateway and 192.168.200.1 as the nameserver.

For example, I have an openbsd/sparc64 VM I've configured thusly;

/etc/hostname.ne0 contains:
inet 192.168.200.20 255.255.255.0
/etc/mygate contains:
192.168.200.100
/etc/resolv.conf contains:
lookup file bind
nameserver 192.168.200.1 (note, on netbsd I had to change this to 8.8.8.8 in order to work)

to make additional tap interfaces you simply re-run the tunctl command, echo 1 to a new /proc.../tapX/proxy_arp, ip link set tapX up and then add the IP you want the new interface to have to the routing table.

For instance, assuming you've already set up tap0, to set up tap1 to have the IP of 192.168.200.30 you'd run the following commands;

sudo -s
tunctl -u $USERNAME
echo 1 > /proc/sys/net/ipv4/conf/tap0/proxy_arp
ip link set tap1 up
route add -host 192.168.200.30 dev tap1

...and bob's your uncle; your tap1 is ready to use.

After you've set up your interface you can invoke it in qemu by adding the following to your qemu invocation;

-net nic -net  tap,ifname=tap0,script=no