[Qemu-devel] Redundant VDE network

[Dmitry Antipov <dmantipov@yandex.ru>]

(This is a partial repost from qemu-discuss@ list since I'm suspecting a bug)

I'm using QEMU 2.1.1 to emulate SPARC system and have vde network between two
VMs and host system, organized as shown:

               host
               tap0
         + 192.168.100.254 +
         |                 |
         |                 |
         vm0               vm1
         eth0              eth0
     192.168.100.1 --- 192.168.100.2

On host, I'm running vde_switch and extra stuff as:

vde_switch -tap tap0 -daemon -mod 660 -group [group]
ip addr add 192.168.100.254/24 dev tap0
ip link set tap0 up
echo 1 > /proc/sys/net/ipv4/ip_forward
iptables -t nat -A POSTROUTING -s 192.168.100.0/24 -o [external network iface] -j MASQUERADE

VMs are running with:

qemu-system-sparc -m 256 -net nic -net vde -hda vm0.img
qemu-system-sparc -m 256 -net nic -net vde -hda vm1.img

Everything looks good, but...

...the problem: I need to build redundant network by using the same method, i.e.
improve the network shown above with:

               host
               tap1
         + 192.168.101.254 +
         |                 |
         |                 |
         vm0               vm1
         eth1              eth1
     192.168.101.1 --- 192.168.101.2

I'm trying to run two vde switches:

vde_switch -sock /tmp/vde0 -tap tap0 -daemon -mod 660 -group [group]
vde_switch -sock /tmp/vde1 -tap tap1 -daemon -mod 660 -group [group]

and run VMs with:

qemu-system-sparc -m 256 -net nic,vlan=0 -net vde,sock=/tmp/vde0,vlan=0 -net nic,vlan=1 -net vde,sock=/tmp/vde1,vlan=1 -hda vm0.img

but the result is:

Warning: hub port hub1port0 has no peer
Warning: vlan 1 with no nics
Warning: netdev hub1port0 has no peer
Warning: requested NIC (anonymous, model unspecified) was not created (not supported by this machine?)

Is this a bug? In general, what's the best method to build redundant network?

Thanks in advance,
Dmitry