I'm trying to start a virtual machine by calling qemu-kvm directly but I am having issues with the vhost file descriptor (vhostfd). According to qemu's source code you must pass the file descriptor of the previously opened vhost_net device so, in order to do this, I am using a python script with something like this: os.open( "/dev/vhost-net", os.O_RDWR). Afterwards it passes this to qemu-kvm as a subprocess. I took this off the command that libvirt generates so I know this work and all kernel modules are enabled. Is there any workaround for this so that I can call qemu-kvm directly without libvirt? Error messages: qemu-kvm: -netdev tap,id=hostnet0,vhost=on,fd=3: TUNGETIFF ioctl() failed: Inappropriate ioctl for device qemu-kvm: -netdev tap,id=hostnet1,vhost=on,fd=4: TUNGETIFF ioctl() failed: Inappropriate ioctl for device Network device arguments passed to qemu-kvm (fd 3 and 4 are the fds that Python opened): -netdev tap,id=hostnet0,vhost=on,fd=3 3<>/dev/tap5,vhostfd=3 -device virtio-net pci,netdev=hostnet0,id=net0,mac=52:54:00:01:cb:a5,bus=pci.0,addr=0x3 -netdev tap,id=hostnet1,vhost=on,fd=4 4<>/dev/tap24,vhostfd=4 -device virtio-net pci,netdev=hostnet1,id=net1,mac=52:50:00:1b:ce:6e,bus=pci.0,addr=0x4 Version: QEMU emulator version 2.6.0 (qemu-kvm-ev-2.6.0-28.el7_3.3.1) Thank you.
