socket: 0.755 network: 0.710 performance: 0.706 device: 0.662 graphic: 0.654 vnc: 0.602 semantic: 0.579 permissions: 0.536 files: 0.492 other: 0.486 PID: 0.466 debug: 0.428 boot: 0.352 KVM: 0.245 virtio serial doesn't work with virtio nic If virtio NIC is not used virtserialport works and delivers data written to /dev/vport0p1 to localhost:4444: qemu-system-x86_64 -enable-kvm -kernel mykernel -initrd myramdisk -device virtio-serial -chardev socket,host=localhost,port=4444,id=agent -device virtserialport,chardev=agent,name=hera.agent -net user -net nic If using virtio nic, write to /dev/vport0p1 succeeds, but no data is delivered to localhost:4444: qemu-system-x86_64 -enable-kvm -kernel mykernel -initrd myramdisk -device virtio-serial -chardev socket,host=localhost,port=4444,id=agent -device virtserialport,chardev=agent,name=hera.agent -net user -net nic,model=virtio This bug exists in 2.0 release, Debian's QEMU 1.7 package and b3706faf from git. Triaging old bug tickets... can you still reproduce this issue with the latest version of QEMU? Or could we close this ticket nowadays? I can't reproduce it now, I don't even remember this issue. Ok, thanks for your answer. Then let's assume that it has been fixed by one of the past releases.