Hi, i have this problem with every network model and also using the newest release 0.12.3, which states that this problem is fixed for virtio-net :-/
host system is slackware64 13.0, guest too! kernel 126.96.36.199 on qemu-kvm-0.12.3
network is bridged using tap and virtio (copy performance around 60MB/s until stall
copying large files via scp from the host to vm's /dev/null works! but copying e.g. the slackware-installiso from a mounted nfs share stalls the network of the virtual machine completely!!
also transfering a few hundret megs via ftp/ftps stalls the network completely!
no network response from the vm (ssh, icmp, etc..)
i can only shutdown and restart the vm using qemu monitor since i am running headless servers!
when using another NIC model the amount of transferable data decreases to only a few megs untill the network stalls :-/
error logs simply say nothing that indcate the problem :-/
anyone some hints or a possible solution for this defect?