You can find the trace-event files in the source tree, if you were talking about those. Anyway, this does not really sound like a bug, so I'm closing this ticket now. If you need general help, please use the qemu-discuss mailing list or the #qemu channel on OFTC IRC instead.
** Changed in: qemu Status: New => Invalid -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1910540 Title: where the trace file "trace-*" Status in QEMU: Invalid Bug description: I compile qemu-system-aarch64 with --enable-trace-backends=simple option, then start qemu with -trace nvme* , qemu start successful but I cann't find the trace file "trace-*" at qemu started directory. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1910540/+subscriptions