From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NrXDn-0002AD-Aj for qemu-devel@nongnu.org; Tue, 16 Mar 2010 09:54:11 -0400 Received: from [199.232.76.173] (port=52995 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NrXDm-00029t-Md for qemu-devel@nongnu.org; Tue, 16 Mar 2010 09:54:10 -0400 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NrXDl-0000W3-53 for qemu-devel@nongnu.org; Tue, 16 Mar 2010 09:54:10 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26310) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NrXDk-0000Vx-PG for qemu-devel@nongnu.org; Tue, 16 Mar 2010 09:54:09 -0400 Date: Tue, 16 Mar 2010 10:53:58 -0300 From: Luiz Capitulino Subject: Re: [Qemu-devel] wake-on-lan & IPMI implementation; real power-off and -no-shutdown Message-ID: <20100316105358.0831df27@redhat.com> In-Reply-To: <20100315155526.GV26239@redhat.com> References: <2378452091-BeMail@laptop> <20100315155526.GV26239@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: =?UTF-8?B?RnJhbsOnb2lz?= Revol , qemu-devel@nongnu.org On Mon, 15 Mar 2010 15:55:26 +0000 "Daniel P. Berrange" wrote: > On Mon, Mar 15, 2010 at 04:01:27PM +0100, Fran?ois Revol wrote: > > Hello, > > while working on a demonstrator for a green-IT project, to show > > scheduled machine shutdown and powering depending on various > > conditions, I wondered if I could use QEMU with wake-on-lan > > transparently, but it seems it's not implemented at all. > > > > I though I could try to add support for it, and with -S it theorically > > should be doable at least for the first boot, but the network packets > > do not go much further until the NIC is actually initialized, as most > > network layers use qemu_can_send_packet() which returns 0 if the > > machine is stopped. > > Hacking this function to return 1 seems to push the packet upward, but > > I couldn't find a single point where I could check for WOL packets, > > different -net subsystems using different code paths. > > > > Also, it seems -no-shutdown doesn't actually "stop the emulation" as > > said in the manual, it actually keeps the vm running (and using cpu), > > despite the OS trying to shutdown via ACPI. At least I tested so with > > Haiku (and acpi=true in kernel config), which properly exits QEMU > > without -no-shutdown. > > Hmm, I think -no-shutdown should at least stop the CPUs executing. It is > not really useful on its own though. The app managing QEMU would want to > use the new JSON based monitor to listen for the SHUTDOWN event to be > emitted, so it can detect the shutdown completing & then take action it > wants either reset the guest, or kill QEMU, etc If I'm not missing something, -no-shutdown calls vm_stop(), which calls pause_all_vcpus().