Re: [Libvir] PATCH 2/2: Support QEMU (+KVM) in libvirt

On Tue, Jan 09, 2007 at 02:57:24PM +0000, Daniel P. Berrange wrote: > On Tue, Jan 09, 2007 at 09:44:44AM -0500, Daniel Veillard wrote: > > On Fri, Jan 05, 2007 at 09:18:53PM +0000, Daniel P. Berrange wrote: > > > The attached patch provides a new driver backend for libvirt which allows > > > management of QEMU instances by talking to the libvirt QEMU daemon. It > > > basically just marshalls libvirt API calls onto the wire & de-marshalls > > > the reply. All the interesting functionality stuff is in the daemon. > > > > Okay, but I'm getting a bit lost about the potential daemons running, > > there one can be autostarted, in the previous patch we also potentially > > fork(fork(daemon)) so I'm wondering how many process are actually running > > in the end, maybe I will need a couple of pictures, like in the current > > architecture page http://libvirt.org/architecture.html (which will have > > to be updated too :-) > > There's two ways its launched: > > - The session bus is auto-launched by libvirt. In this scenaro, libvirt > does the double fork() magic to dis-inherit the libvirt_qemud process > - The system bus is started manually. In this case, it runs in foreground > unless you use the --daemon command line argument to make it do the > double-fork() into background. okay, and the former auto exits while the latter sticks until stopped I there any way we can avoid /etc/init.d/libvirt <grin/> ?

> > > dom = "XML-RPC "; > > > break; > > > + case VIR_FROM_QEMUD: > > > + dom = "QEMUD "; > > > + break; > > > } > > > if ((err->dom != NULL) && (err->code != VIR_ERR_INVALID_DOMAIN)) { > > > domain = err->dom->name; > > > > I guess some new error code will need to be added too once quemud_internal.c > > is being updated ... Hum, how do we process errors provided by the server ? > > The libvirt_qemud daemon includes <libvirt/virterror.h> and sends back the > appropriate error codes over the wire, along with a message. This is used > to call __virRaiseError - see the qemudPacketError() function at the top > of the qemud_internal.c file - this function is called whenver the wire > protocol gives back an unexpected result So QEmu/KVM runtime generates no new errors ? Sounds surprizing to me ...