static uint32_t virtio_net_bad_features(VirtIODevice *vdev) { uint32_t features = 0; /* Linux kernel 2.6.25. It understood MAC (as everyone must), * but also these: */ features |= (1 << VIRTIO_NET_F_MAC); features |= (1 << VIRTIO_NET_F_GUEST_CSUM); features |= (1 << VIRTIO_NET_F_GUEST_TSO4); features |= (1 << VIRTIO_NET_F_GUEST_TSO6); features |= (1 << VIRTIO_NET_F_GUEST_ECN); return features & virtio_net_get_features(vdev); }