On 07/10/2012 07:00 AM, xuanmao_001 wrote:

Hi, all. I want to know when I press run button. start a domain. What is the procedure of libvirt internal. I know it will call virDomainCreate(),then qemuDomainStart() -> qemuDomainStartWithFlags(). what is the next?

I'm assuming you pushed the run button within virt-manager or some other gui. This makes a call into libvirt.so virDomainCreate(), which then bundles the arguments into an RPC call to pass to libvirtd using the code in src/remote. Then libvirtd (the code in daemon/) unbundles the RPC call, calls its own copy of virDomainCreate(), which then forwards into qemuDomainStart() (src/qemu). So you got that part correct. Within the body of qemuDomainStart() are calls to helper functions to build the command line (src/qemu/qemu_command.c) as well as creating the qemu process (src/qemu/qemu_process.c) and associated monitor connection (src/qemu/qemu_monitor.c). You can view the guest log to see the command line that was created. Beyond that, I'd suggest you compile your own version of libvirtd with CFLAGS=-O0, then step through virDomainCreate() under gdb if you really want to know what's happening. -- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org