Anthony Liguori writes: > On 04/20/2011 10:33 PM, Jason Wang wrote: > > Krishna Kumar2 writes: > > > Thanks Jason! > > > > > > So I can use my virtio-net guest driver and test with this patch? > > > Please provide the script you use to start MQ guest. > > > > > > > Yes and thanks. Following is a simple script may help you start macvtap mq > > guest. > > > > qemu_path=./qemu-system-x86_64 > > img_path=/home/kvm_autotest_root/images/mq.qcow2 > > vtap_dev=/dev/tap104 > > mac=96:88:12:1C:27:83 > > smp=2 > > mq=4 > > > > for i in `seq $mq` > > do > > vtap+=" -netdev tap,id=hn$i,fd=$((i+100)) $((i+100))<>$vtap_dev" > > So you are basically dup()'ing the tap device. > > Does this actually improve performance at all? >
The script maybe not clear. It works only for macvtap (tap does not have multiqueue support and I plan to add it). A macvtap device needs to be created first by ip command. The multiqueue was achieved by opening the macvtap device many times. Each time the user open to macvtap device, a new queue (sock) was created. Then macvtap device then can forward the packets to different sock/fd based on their RX queue of physical nics. So the fd could be used to registered as a backend for vhost/qemu. Performance improvement is expected when using smp guest with mq virtio-net and mq nic. > Regards, > > Anthony Liguori > -- Jason Wang
