From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MRSHE-0004qY-4U for qemu-devel@nongnu.org; Thu, 16 Jul 2009 10:49:40 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MRSH9-0004ou-AJ for qemu-devel@nongnu.org; Thu, 16 Jul 2009 10:49:39 -0400 Received: from [199.232.76.173] (port=38499 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MRSH9-0004or-2F for qemu-devel@nongnu.org; Thu, 16 Jul 2009 10:49:35 -0400 Received: from mx2.redhat.com ([66.187.237.31]:44000) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MRSH8-0005Az-FA for qemu-devel@nongnu.org; Thu, 16 Jul 2009 10:49:34 -0400 Date: Thu, 16 Jul 2009 20:19:19 +0530 From: Amit Shah Subject: Re: [Qemu-devel] [PATCH][RESEND] Add monitor command for system_reboot Message-ID: <20090716144919.GA32176@amit-x200.redhat.com> References: <20090707192631.GQ11590@us.ibm.com> <20090708075601.GJ28046@redhat.com> <4A549990.2060205@us.ibm.com> <20090708132623.GN26640@redhat.com> <4A54A367.3010603@us.ibm.com> <20090708135607.GO26640@redhat.com> <20090708154349.GT11590@us.ibm.com> <4A54C308.8060307@redhat.com> <20090716085843.GA14243@amit-x200.redhat.com> <20090716143959.GC16461@shareable.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090716143959.GC16461@shareable.org> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jamie Lokier Cc: Anthony Liguori , Ryan Harper , Avi Kivity , Gleb Natapov , qemu-devel@nongnu.org On (Thu) Jul 16 2009 [15:39:59], Jamie Lokier wrote: > Amit Shah wrote: > > On (Wed) Jul 08 2009 [19:02:16], Avi Kivity wrote: > > > On 07/08/2009 06:43 PM, Ryan Harper wrote: > > >>> That suffers from the same problem as a system_reboot command in that > > >>> the guest may never start the shutdown. If that's an acceptable > > >>> limitation, then we might as well implement it directly in QEMU as > > >>> system_reboot so its easily available to everyone. Make 'system_reboot' > > >>> take an optional timeout arg (default to 60 seconds) after which it > > >>> cancels its plans. > > >>> > > >> > > >> This seems the most reasonable thing to me. As already mentioned, > > >> system_powerdown already is non-deterministic since the guest could > > >> ignore the ACPI event. > > >> > > > > > > It could also send the guest to sleep or initiate the self destruct > > > sequence. I don't think we should press the power button unless the > > > user explicitly asked us to. This means we'll need a guest agent like > > > Xen. > > > > This is another use-case for vmchannel (or virtio-serial) where the user > > exists within qemu. > > What happens then the guest is non-responsive because it crashed, or > the agent isn't working, or the guest doesn't support virtio? In the first two cases it has to be forced (as for a physical machine). The last case can be detected before using any virtio-serial functionality. > Some way to override the guest is needed for all reboot/powerdown options. Sure, just that a PV reboot/powerdown option is more reliable if the guest ignores the ACPI events. > "kill -9 $(pidof kvm)" is really unacceptable, but I've had to do it > on several occasions unfortunately. > > Ideally, an option to those commands "--force" to ignore the guest and > just do it, and an option like "--timeout-force=5" to behave like > holding down the power button on a real computer. > > (It would be nice to be able to change the value of -no-shutdown and > -no-reboot from the monitor, too.) > > -- Jamie Amit