On Tue, Apr 08, 2008 at 04:45:23AM -0400, Daniel Veillard wrote:
Then what happen if you pass a wrong string ? Is there any way to get a meaningful error back from qemu and report it. Thet would IMHO be quite better than tracking the evolution of the emulation in QEmu, plus the added benefit of not being tied to a strict version of QEmu,
The error handling in this part of the code seems a bit confused at the moment. For example: if (virExecNonBlock(conn, argv, &vm->pid, vm->stdin, &vm->stdout, &vm->stderr) == 0) { /* [add new qemu to list of VMs] */ } /* [free up various resources] */ if (virEventAddHandle(vm->stdout, POLLIN | POLLERR | POLLHUP, qemudDispatchVMEvent, driver) < 0) { qemudShutdownVMDaemon(conn, driver, vm); return -1; } /* [another call to virEventAddHandle] */ if (qemudWaitForMonitor(conn, driver, vm) < 0) { qemudShutdownVMDaemon(conn, driver, vm); return -1; } return 0; If virExecNonBlock fails, because one of the system calls such as fork(2) or pipe(2) fails, then vm->stdout may be uninitialized. I think it will assume the value 0 in this case and virEventAddHandle will quite happily register a handler for fd 0. On the other hand it is tricky to know what to do when launching a process. In the case where KVM doesn't understand part of the command line arguments, the fork & exec will both succeed and the earliest point where we will see any error will be at qemudWaitForMonitor (because the monitor won't come up -- note this code is synchronous). Rich. -- Richard Jones, Emerging Technologies, Red Hat http://et.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top