Hi,here is my problem
1 ./configure --enable-trace-backends=simple
    make
    make install
    echo virtio_notity > /tmp/events
    echo virtio_queue_notify >> /tmp/events
2  I use a xml file run a virtual machine
3  qemu-system_x86_64 -trace events=/tmp/events 
4   ./scripts/simpletrace.py trace-events trace-*


But do not get trace.log. and when i check trace-* using 'vim' i find the file is almost empty.
I tried many times, including reinstall qemu,but still don't work.
when i use qemu -trace -m 2048 ........... commandline create virtual machine ,the vm become very slow and still no trace.log.
I am a green hand, help!!!!!