Hi Stefan, Prerna, I pulled down QEMU tracing code from git://repo.or.cz/qemu/stefanha.git and tried to use it to trace something in virtio-9p code. I don't have any knowledge of how traces are implemented and I just went with the documentation. With help from Prerna, I was able to insert a trace point and observe it getting hit from the QEMU monitor. However, I have a few questions about this. Could you please help me out?
*) My understanding is the traces are dumped to a file only when the trace buffer gets filled. Is there a way to: a) Forcibly dump the contents of the buffer when needed. b) When QEMU exits it should dump the buffer. Doesn't seem to be doing this now. c) A way to specify the file into which it writes the traces. *) Is QEMU monitor the only way to enable/disable trace points? Is it possible to programmatically enable/disable trace points from within QEMU code? If that is not possible, is it possible to specify all trace points to be enabled in a text file and ask QEMU to read the file when it starts up? *) Is it possible to enable/disable a bunch of trace points at one shot? Can trace points be grouped in some way? Can I say "enable all trace points in a particular .c file" or "enable all trace points in these 2 functions"? Thanks a lot for your help. -Sripathi.
