Re: [Xen-devel] Early ACPI events prevent subsequent ACPI functionality on xen 4.3 + HVM domU

[George Dunlap <george.dunlap@xxxxxxxxxxxxx>]

On 21/05/13 18:31, Sander Eikelenboom wrote:
> Tuesday, May 21, 2013, 6:09:33 PM, you wrote:
>
> > On 05/21/2013 04:59 PM, Alex Bligh wrote:
> > > George,
> > >
> > > --On 21 May 2013 16:23:00 +0100 George Dunlap
> > > <george.dunlap@xxxxxxxxxxxxx> wrote:
> > >
> > > > On 05/21/2013 04:16 PM, Alex Bligh wrote:
> > > > > George,
> > > > >
> > > > > --On 21 May 2013 14:39:55 +0100 George Dunlap
> > > > > <George.Dunlap@xxxxxxxxxxxxx> wrote:
> > > > >
> > > > > > So this appears to be an xl toolstack thing.  I managed to reproduce
> > > > > > your results using "xl shutdown -F [domain]"; but if you then do "xl
> > > > > > trigger [domian] power", the domain shuts down as normal.
> > > > > OK. But doesn't the power thing yank the power rather than send a
> > > > > clean shutdown?
> > > > No -- if you push the button just once on most modern hardware it will
> > > > send an ACPI "poweroff" event that the OS handles gracefully.  That's
> > > > what gets sent when you do "xl trigger [domain] power".  If the OS
> > > > ignores it (either on real hardware or virtual hardware) nothing happens.
> > > > On real hardware you have to then hold down the button for 5 seconds for
> > > > a hard-shutdown, with xl you have to do "xl destroy".
> > > OK, great. I am guessing the reason why 'xl shutdown' doesn't do
> > > that is to cope with (a) non-HVM domains, and (b) old fashioned
> > > HVM domains with PV support but not ACPI support. Correct?
> > >
> > > > > We are using libxl here (admittedly having looked carefully at
> > > > > the xl code for guidance) and get the same problem.
> > > > The relevant xl code is here:
> > > >
> > > >       rc=libxl_domain_shutdown(ctx, domid);
> > > >       if (rc == ERROR_NOPARAVIRT) {
> > > >           if (fallback_trigger) {
> > > >               fprintf(stderr, "PV control interface not available:"
> > > >                       " sending ACPI power button event.\n");
> > > >               rc = libxl_send_trigger(ctx, domid, LIBXL_TRIGGER_POWER, 0);
> > > >           } else {
> > > >               fprintf(stderr, "PV control interface not available:"
> > > >                       " external graceful shutdown not possible.\n");
> > > >               fprintf(stderr, "Use \"-F\" to fallback to ACPI power
> > > > event.\n");
> > > >           }
> > > >       }
> > > >
> > > > It looks like libxl_domain_shutdown() will only use the PV shutdown
> > > > method.  If that method is not available, then it will call
> > > > libxl_send_trigger().
> > > OK. Well if that's the case, why is it not working? i.e. how
> > > is using 'xl trigger power' a workaround? As our testing was
> > > on xl (as well as libxl). Perhaps libxl_domain_shutdown
> > > is returning an error other than ERROR_NOPARAVIRT or no error
> > > at all?
> > xl/libxl is working as designed. xl tried libxl_domain_shutdown() first.
> >    libxl saw that there were PV drivers available, so it sent the PV
> > shutdown signal over xenstore and returned success.  libxl and xl have
> > no way of knowing that the signal was never received, so it never falls
> > back to ACPI.
> At a sidenote ...
>
> This reminds me that there still is the issue that a HVM domain without PV 
> drivers doesn't shutdown properly with the standard init.d scripts.
BTW, if you want this to get attention, you should probably either reply 
to that thread, or start a new thread.  Starting a new topic on an 
unrelated thread is generally frowned upon. :-)
 -George


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel