I'm trying to test some software on a big endian system to ensure compatibility.  My plan is to use qemu on Ubuntu 12.04 to emulate a MIPS system.  So far I've been able to create the quest system successfully, but I haven't been able to network it with the host system.  I can access the outside world from the guest system (e.g. wget or apt-get), but my attempts at setting up samba have failed.According to this, in QEmu 1.1 and newer the network bridge helper can set tun/tap up for you without the need for additional scripting.  I'm trying to use that since I've seen different versions of the scripts.  Right now qemu-system-mips -version reports the following:QEMU emulator version 1.0.50 (Debian 1.0.50-2012.03-0ubuntu2.1), Copyright (c) 2003-2008 Fabrice BellardI've compiled from the 1.4.1 source and used the version from apt-get.  Both report the same thing.  I'm working under the assumption that I have version 1.1 or later despite what -version is telling me.  Anyway, the next instruction was to turn on the setuid attribute for the default network helper:sudo chmod u+s /usr/local/libexec/qemu-bridge-helperNext I created a bridge.conf file in /etc/qemu/ and /usr/local/etc/qemu with -rw-r--r-- for permissions.  The contents of the file are:allow br0If I start QEmu with the following command:qemu-system-mips -M malta -kernel vmlinux-2.6.32-5-4kc-malta -hda disk.img -append root=/dev/sda1 console=ttyS0 -nographic -net nic -net bridge,br=br0 -smb /home/uli/sambaor with qemu-system-mips -M malta -kernel vmlinux-2.6.32-5-4kc-malta -hda disk.img -append root=/dev/sda1 console=ttyS0 -nographic -netdev bridge,id=hn0 -device virtio-net-pci,netdev=hn0,id=nic1or with qemu-system-mips -M malta -kernel vmlinux-2.6.32-5-4kc-malta -hda disk.img -append root=/dev/sda1 console=ttyS0 -nographic  -netdev tap,helper=/usr/local/libexec/qemu-bridge-helper,id=hn0 -device virtio-net-pci,netdev=hn0,id=nic1I get the following error:failed to get mtu of bridge `br0': No such devicefailed to launch bridge helperqemu-system-mips: -net bridge,br=br0: Device 'bridge' could not be initializedFair enough, I didn't create the br0 bridge.  I've tried creating one with a script I don't understand, but then my quest MIPS QEmu system no longer connects to anything.  It sees br0, but it doesn't get an IP address.  Clearly I'm doing something wrong here:ifconfig br0 downbrctl delbr br0ifconfig eth2 0.0.0.0 promisc upbrctl addbr br0brctl setfd br0 0brctl addif br0 eth2echo 1 > /proc/sys/net/ipv4/conf/br0/proxy_arpecho 1 > /proc/sys/net/ipv4/conf/eth2/proxy_arpecho 1 > /proc/sys/net/ipv4/ip_forwarddhclient br0ifconfig br0 upIs there an easier way to do this?  Personally, I would be fine just using the SMB server on \10.0.2.4\qemu that's described here, but that hasn't worked for me either (115 errors when I try to mount the share, presumably because of networking trouble).UpdateOnce I create the bridge, I see the following output from ifconfig on the host machine:br0       Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX:XX            inet addr:10.2.32.101  Bcast:10.2.32.255  Mask:255.255.255.0                    UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1          RX packets:85 errors:0 dropped:0 overruns:0 frame:0          TX packets:51 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:0           RX bytes:8235 (8.2 KB)  TX bytes:9227 (9.2 KB)eth2      Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX:XX            UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1          RX packets:196581 errors:0 dropped:0 overruns:0 frame:0          TX packets:44205 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000           RX bytes:139517339 (139.5 MB)  TX bytes:3365206 (3.3 MB)Checking the brctl show output, I see the following:bridge name     bridge id           STP enabled     interfacesbr0             8000.XXXXXXXXXXXX       no              eth2Now I start the quest system in QEmu.  If I run ifconfig, I see the following:eth0      Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX:XX            UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1          RX packets:536 errors:1 dropped:51 overruns:0 frame:0          TX packets:13 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000           RX bytes:55083 (53.7 KiB)  TX bytes:2862 (2.7 KiB)          Interrupt:10 Base address:0x1020And the bridge looks like this:bridge name     bridge id           STP enabled     interfacesbr0             8000.XXXXXXXXXXXX   no      eth2                                                        tap0Unfortunately with this setup, the quest system has lost the limited user mode networking it once had (i.e. wget and apt-get no longer work).  The only IP address I see is for the bridge, so I'm not sure how the quest will appear on the network.  The host still appears, at the same IP address as br0.UpdateHere is the output from iptables -LChain INPUT (policy ACCEPT)target     prot opt source               destination         Chain FORWARD (policy ACCEPT)target     prot opt source               destination         Chain OUTPUT (policy ACCEPT)target     prot opt source               destination   
Networking and Samba from a quest OS running on qemu
networking;samba;qemu;bridge;mips