On Mon, Jan 12, 2009 at 04:37:50PM +0100, Guido G?nther wrote:
> On Mon, Jan 12, 2009 at 11:30:19AM +0000, Daniel P. Berrange wrote:
> > There's different needs for each file descriptor
> >
> > - stdin_fd - this is only ever used for incoming migration data
> > all other times it is hooked up to /dev/null. So we don't need
> > to keep this FD around at all
> Agreed.
>
> > - stdout_fd - AFAIK, the only time we get any data on stdout is
> > when we run qemu -help to check support args. Current code will
> > read & log all data on stdout, but I believe this is effectively
> > nothing and so we could just hook it to /dev/null & ignore it
> We can just dup that one too while at it in case qemu/kvm should dump
> anything else there.
>
> > - stderr_fd - libvirtd reads this FD & logs the data to the domain
> > logfile in /var/log/libvirt/qemu/$NAME.log. Instead of having
> > the daemon process this logging, we can just dup() the file straight
> > onto the logfile FD, so data will be logged even when libvirtd is
> > not running. The only minor complication is that we need to parse
> > the logfile to get the monitor TTY path.
> There's one more thing (which was my intial reason for asking): we also use
> this fd in qemudDispatchVMEvent() to detect vm shutdown:
>
> if (events & VIR_EVENT_HANDLE_READABLE) {
> if (qemudVMData(driver, vm, fd) < 0)
> failed = 1;
> } else {
> quit = 1;
> }
> }
>
> if (failed || quit) {
> event = virDomainEventNewFromObj(vm,
> VIR_DOMAIN_EVENT_STOPPED,
> quit ?
> VIR_DOMAIN_EVENT_STOPPED_SHUTDOWN
> :
> VIR_DOMAIN_EVENT_STOPPED_FAILED);
> qemudShutdownVMDaemon(NULL, driver, vm);
> if (!vm->persistent) {
> virDomainRemoveInactive(&driver->domains,
> vm);
> vm = NULL;
> }
>
> Using the monitor fd for this instead should work. Would that be o.k.?
Yeah, I thought it was already using the monitor FD for this !
Daniel
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