[Qemu-devel] qemu-2.2 using trace event

[??????]

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!!!!!