I'm trying to solve a problem where bringing up a virtio network device in a KVM guest hangs the guest.
Start QEMU with these options: -net nic,model=virtio -net tap,script=/root/qemu-ifup The qemu-ifup script is pretty simple, just adds the interface passed in to a bridge: #!/bin/sh bridge=br0 guest_device=$1 ifconfig $guest_device up brctl addif $bridge $guest_device The guest kernel finds the virtio device, but when bringing up the virtio eth0 device in the guest the ifconfig hangs the guest. In the host, the bridge (br0) is able to send and receive packets. The tap device created by QEMU shows packets sent, but none received: tap0 Link encap:Ethernet HWaddr 0A:02:56:5A:72:C6 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:257 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:0 (0.0 B) TX bytes:17592 (17.1 KiB) Wondered if anyone had any ideas on how to further diagnose what might be going on. Thanks, Stuart