On Thu, 2013-05-16 at 11:40 +0300, Michael S. Tsirkin wrote: > On Thu, May 16, 2013 at 09:20:55AM +0100, Nicholas Thomas wrote: > > Hi, > > > > On Thu, 2013-05-16 at 09:27 +0300, Michael S. Tsirkin wrote: > > > On Thu, May 16, 2013 at 09:24:05AM +0300, Michael S. Tsirkin wrote: > > > > Is this with or without vhost-net in host? > > > > > > never mind, I see it's without. > > > Try to enable vhost-net (you'll have to switch to -netdev syntax > > > for that to work) and see if this help. > > > If it does it's likely a qemu bug if not probably a guest bug. > > > > Switching to -netdev is non-trivial for me, unfortunately. > > Interesting. Why is that?
Our setup is bond0 <-> vlanX <-> bridgeX <-> [ tap devices ] and we do all that outside of qemu at the moment, specifying -net tap,ifname=... - we also run some processes on the TAP interface and insert a bunch of ebtables rules between creating it and starting qemu. Duplicating that with -net bridge seemed close to impossible, and -netdev tap was throwing EBUSY from /dev/net/tun. I guess our external magic should be using ,fd= instead. > > Anyway, it's > > definitely a qemu bug - it happens on kernels 3.2 and 3.9 with 1.4.1, > > but doesn't happen with qemu 0.15.0 or 1.5.0rc1. > > > > I'll have a dig through git to see if I can identify the patch that > > resolves it. It feels-like qemu sometimes stops reading from the tap > > file descriptor between ipxe exiting and the linux kernel bringing up > > the network interface, and never recovers from that. > > > > /Nick > > You can try to bisect, yes. Work have decided to accept 1.5.0 when it arrives instead, so I'm afraid I won't be working on this after all. /Nick