I found an issue where the libvirt-generated qemu command line uses the 'script' parameter incorrectly in combination with -net. It turns out it does not lead to a failure today but could later if qemu behaviour changes. The F11 virtualization host has its primary interface configured as a bridge. When using virt-manager to set up the guest, therefore, I made use of the host bridged interface and that is reflected in the qemu-kvm command line. This is the command line that ended up being used: /usr/bin/qemu-kvm -S -M pc -m 2048 -smp 8 -name f11-test -uuid 41ed0f4f-cb0d-7d6a-ffb6-b33106d519ef -monitor pty -pidfile /var/run/libvirt/qemu//f11-test.pid -boot c -drive file=/var/lib/libvirt/images/f11-test-1.img,if=virtio,index=0,boot=on -drive file=/dev/sdb,if=virtio,index=1 -net nic,macaddr=54:52:00:4a:ee:0e,vlan=0,model=virtio -net tap,fd=21,script=,vlan=0,ifname=vnet0 -serial pty -parallel none -usb -usbdevice tablet -vnc 127.0.0.1:0 -soundhw es1370 The important part with respect to this bug is: -net tap,fd=21,script=,vlan=0,ifname=vnet0 As far as I can tell in the documentation and my own by-hand runs of this, 'script=' is not correct. It should be 'script=no' It turns out that this doesn't generate an error. When I was trying my own runs of qemu-kvm based on the libvirt-generated command line, I added my own tap interface with tunctl and tried to point qemu-kvm at that. Because I did it this way, I did not have the 'fd=x' piece in there. In that scenario, qemu-kvm refused to start with this syntax error: /etc/qemu-ifup: could not launch network script Could not initialize device 'tap' This was the FAILING attempted command line: /usr/bin/qemu-kvm -M pc -m 2048 -smp 8 -name f11-test -uui41ed0f4f-cb0d-7d6a-ffb6-b33106d519ef -pidfile /var/run/libvirt/qemu//f11-test.pid -boot c -drive file=/var/lib/libvirt/images/f11-test-1.img,if=virtio,index=0,boot=on -drive file=/dev/sdb,if=virtio,index=1,cache=none -net nic,macaddr=54:52:00:4a:ee:0e,vlan=0,model=virtio -net tap,script=,vlan=0,ifname=tap0 -parallel none -usb -usbdevice tablet -soundhw es1370 And this is the important part with respect to this bug: -net tap,script=,vlan=0,ifname=tap0 The final command line I used was this, and it worked (replacing the script= with script=no): /usr/bin/qemu-kvm -M pc -m 2048 -smp 8 -name f11-test -uuid 41ed0f4f-cb0d-7d6a-ffb6-b33106d519ef -pidfile /var/run/libvirt/qemu//f11-test.pid -boot c -drive file=/var/lib/libvirt/images/f11-test-1.img,if=virtio,index=0,boot=on -drive file=/dev/sdb,if=virtio,index=1,cache=none -net nic,macaddr=54:52:00:4a:ee:0e,vlan=0,model=virtio -net tap,script=no,vlan=0,ifname=tap0 -parallel none -usb -usbdevice tablet -soundhw es1370 And this is the important part with respect to this bug: -net tap,script=no,vlan=0,ifname=tap0 So I've filed this minor bug just in case, if qemu-kvm changes so that script= isn't ignored entirely when fd=x is supplied, that libvirt doesn't start tripping on this. Not a show-stopper by any means. qemu-kvm-0.10.4-4.fc11.x86_64 libvirt-0.6.2-11.fc11.x86_64 virt-manager-0.7.0-5.fc11.x86_64
Thanks Erik, try libvirt-0.6.2-12.fc11 from updates-testing *** This bug has been marked as a duplicate of bug 503275 ***
Hello. Looks like this showed up as a released update. I cranked up a virtual machine. I can confirm that the qemu command line doesn't use the script parameter any more for the use case I reported on. [root@nada1 ~]# ps -ef | grep qemu root 3189 1 33 13:39 ? 00:00:02 /usr/bin/qemu-kvm -S -M pc -m 2048 -smp 8 -name f11-test -uuid 41ed0f4f-cb0d-7d6a-ffb6-b33106d519ef -monitor pty -pidfile /var/run/libvirt/qemu//f11-test.pid -boot c -drive file=/var/lib/libvirt/images/f11-test-1.img,if=virtio,index=0,boot=on -drive file=/dev/sdb,if=virtio,index=1 -net nic,macaddr=54:52:00:4a:ee:0e,vlan=0,model=virtio -net tap,fd=19,vlan=0 -serial pty -parallel none -usb -usbdevice tablet -vnc 127.0.0.1:0 -soundhw es1370 root 3222 3111 0 13:39 pts/0 00:00:00 grep qemu [root@nada1 ~]# rpm -q libvirt libvirt-0.6.2-12.fc11.x86_64 Looks good. thanks.