Re: [Xen-devel] BUG: [?] host-only networking under HVM is broken with custom script

[Keir Fraser <keir.fraser@xxxxxxxxxxxxx>]

I doubt your script is getting executed. HVM guests have a script run by
qemu-dm: the default location of that is /etc/xen/qemu-ifup and I think xend
never overrides that. You probably need to do some command-line splicing in
tools/python/xen/xend/image.py -- we already extract the 'bridge' parameter
and pass that along to qemu-dm, but the same is not done for the 'script'
parameter.

 -- Keir

On 2/6/08 07:37, "Ray Barnes" <tical.net@xxxxxxxxx> wrote:

> Resending this to xen-devel since no one rendered a response on xen-users
> 
> ---
> 
> I'm bumping into a problem which looks like a bug.  Perhaps it's for
> lack of knowledge (and _documentation_ of HVM).  If I do the
> following:
> 
> brctl addbr bmette31
> ifconfig bmette31 1.2.3.249 netmask 255.255.255.248
> xm create bmette31
> 
> Where "bmette31" has a config file that has a vif entry like: vif = [
> 'type=ioemu, mac=00:16:3e:00:00:07, bridge=bmette31']  this works
> *just fine*.  I'm able to route through the host to the HVM domain
> which is set to 1.2.3.250.  However, whenever I use a script which is
> loosely based on a vif-bridge script that I got from /etc/xen/scripts
> running Xen 3.2.1 compiled from source, it does not work.
> Specifically, I can reach 1.2.3.249 from the outside but not
> 1.2.3.250.  As far as I can tell, the problem is that whenever 'brctl
> addbr bmette31' is invoked from outside the script, networking between
> the host and the HVM guest works fine, but when invoked from within
> the script, networking between the host and the HVM guest does not
> work.  Note that while the domain is running (and using the script
> below), 'brctl show' indicates that I have a bridge called bmette31
> and that 'ifconfig bmette31' shows the right IP.  So just to recap -
> if I comment out 'brctl addbr bmette31' from the script below and run
> it manually then start the HVM guest, networking is fine, but if I run
> that from within the script it does not work.
> 
> One thing I notice immediately is that when I create the bridge from
> the command-line, the bridge starts out with all zeros in the MAC
> address, and once the custom script runs upon starting the domU, it
> gets a MAC address like so:
> 
> bridge name     bridge id               STP enabled     interfaces
> bmette31                8000.8a10ff068f3f       no              vif61.0
> 
> That's the working scenario as seen by 'brctl show'.  The non-working
> scenario (invoking 'brctl addbr bmette31' from within the script) look
> like this:
> 
> bridge name     bridge id               STP enabled     interfaces
> bmette31                8000.feffffffffff       no              vif62.0
> 
> FYI, I only care about this because I'm trying to make my domUs
> extremely portable (relying only on a config file and a vif script),
> i.e. for live migration.  Staticly creating hundreds (thousands?) of
> bridges across all nodes isn't an option.  Any ideas?
> 
> 
> -Ray
> 
> 
> #!/bin/bash
> #
> #vif bridge script for HVMs
> #invoke like this:
> #
> #vif = [ 'type=ioemu, mac=00:16:3e:00:00:07, bridge=bmette31,
> script=vif-bmette31' ]
> 
> /usr/sbin/brctl addbr bmette31
> 
> dir=$(dirname "$0")
> . "$dir/vif-common.sh"
> 
> bridge=${bridge:-}
> bridge=$(xenstore_read_default "$XENBUS_PATH/bridge" "$bridge")
> 
> 
> RET=0
> ip link show $bridge 1>/dev/null 2>&1 || RET=1
> if [ "$RET" -eq 1 ]
> then
> #       do_without_error brctl addbr "$bridge"
>     fatal "Could not find bridge device $bridge"
> fi
> 
> case "$command" in
>     online)
>         setup_bridge_port "$vif"
>         add_to_bridge "$bridge" "$vif"
>         sleep 2
>         ifconfig "$bridge" 1.2.3.249 netmask 255.255.255.248
>         ;;
> 
>     offline)
>         do_without_error ifconfig "$bridge" down
>         do_without_error brctl delbr "$bridge"
>         ;;
> esac
> 
> 
> log debug "Successful vif-bridge $command for $vif, bridge $bridge."
> if [ "$command" == "online" ]
> then
>   success
> fi
> 
> _______________________________________________
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> http://lists.xensource.com/xen-devel



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