Re: [Qemu-devel] [PATCH 0/5] Add some tracepoints for clarification of the cause of troubles

[Paolo Bonzini <pbonzini@redhat.com>]

> > Wouldn't you get the same information from the command line?
> 
> I think the information you said is different from what I meant. The
> information I wanted to know is whether QEMU creates/deletes a device
> successfully or not.

Failing to create a device will always exit QEMU.  If you cannot assume
that, you're really in debugging territory and your tools should
be the "info" monitor commands (info qtree, info pci) or gdb...


> We cannot get it from the command line.
> I was sure I specified a NIC device for the guest, but the Windows
> guest didn't have it when it booted.  There were two possibilities.  One
> was QEMU failed to create the NIC device, and the other was QEMU created
> it successfully and the Windows guest failed to detect it.  Since QEMU
> output limited message at the moment, it was difficult to prove that
> it was not QEMU's issue.  I took a coredump of the QEMU and proved
> the QEMU must have a valid structures for the NIC device.  I believe the
> tracepoints could have allowed me to figure out where the issue
> existed a lot faster and easier. 

Had you tried "info qtree" or "info pci"?

Paolo