From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MOZP2-0000DT-Sb for qemu-devel@nongnu.org; Wed, 08 Jul 2009 11:49:48 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MOZOy-0000Ao-5c for qemu-devel@nongnu.org; Wed, 08 Jul 2009 11:49:48 -0400 Received: from [199.232.76.173] (port=39573 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MOZOx-0000Ag-VQ for qemu-devel@nongnu.org; Wed, 08 Jul 2009 11:49:44 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:58305) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1MOZOx-0002Ra-It for qemu-devel@nongnu.org; Wed, 08 Jul 2009 11:49:43 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e3.ny.us.ibm.com (8.13.1/8.13.1) with ESMTP id n68FiBP1006563 for ; Wed, 8 Jul 2009 11:44:11 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n68Fngps250000 for ; Wed, 8 Jul 2009 11:49:42 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n68FlBvD008651 for ; Wed, 8 Jul 2009 11:47:11 -0400 Message-ID: <4A54C012.2080003@us.ibm.com> Date: Wed, 08 Jul 2009 10:49:38 -0500 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH][RESEND] Add monitor command for system_reboot 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> In-Reply-To: <20090708154349.GT11590@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ryan Harper Cc: qemu-devel@nongnu.org, Gleb Natapov 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's a different class of non-determinism though. With system_powerdown, you make a request to the guest. You don't know whether the guest will comply with the request. The same level of non-determinism exists with ballooning. With system_reboot, you're taking an action (system_reset) and what's not deterministic is whether you're taking that action based on what someone requested on the monitor (system_reboot) verses whether you're taking that action based on something the user did (shutdown). In the later case, you're action is functionally incorrect. -- Regards, Anthony Liguori