From patchwork Fri Nov 15 16:13:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sergio Lopez X-Patchwork-Id: 1195726 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="PR0sXXMe"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47F3ND4Bzpz9s4Y for ; Sat, 16 Nov 2019 03:15:08 +1100 (AEDT) Received: from localhost ([::1]:41340 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iVeFW-0007XK-Du for incoming@patchwork.ozlabs.org; Fri, 15 Nov 2019 11:15:06 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:49964) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iVeEI-0006UI-Uc for qemu-devel@nongnu.org; Fri, 15 Nov 2019 11:13:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iVeEH-0002kr-Na for qemu-devel@nongnu.org; Fri, 15 Nov 2019 11:13:50 -0500 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:44039 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iVeEH-0002j9-Jx for qemu-devel@nongnu.org; Fri, 15 Nov 2019 11:13:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573834427; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aJ8AgVP7ItkR5Ul/UyuU0SvDmcwXtFrRgDShktO4bLk=; b=PR0sXXMeMesGfP+mdde8TvtBdpIbx7cHGlnrFUMt8u3cAQYpgZHA8/b848VS1bImYzVA81 Ru8YwHejIuxoPWRwT6coPy1u6bd1Hll9D+z1r9/6SecnjnU549gYCoLXQrumuxJmiAqFqv rmEHI2qPkO1vbF2yLbM2AwIr6DTs6PY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-320-aT8f6FSvPE6hhFDDbNdb1w-1; Fri, 15 Nov 2019 11:13:46 -0500 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B0A4C10832A5 for ; Fri, 15 Nov 2019 16:13:45 +0000 (UTC) Received: from dritchie.redhat.com (unknown [10.33.36.15]) by smtp.corp.redhat.com (Postfix) with ESMTP id ADEF15ED29; Fri, 15 Nov 2019 16:13:44 +0000 (UTC) From: Sergio Lopez To: qemu-devel@nongnu.org Subject: [PATCH 2/2] docs/microvm.rst: add instructions for shutting down the guest Date: Fri, 15 Nov 2019 17:13:38 +0100 Message-Id: <20191115161338.42864-3-slp@redhat.com> In-Reply-To: <20191115161338.42864-1-slp@redhat.com> References: <20191115161338.42864-1-slp@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-MC-Unique: aT8f6FSvPE6hhFDDbNdb1w-1 X-Mimecast-Spam-Score: 0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 205.139.110.61 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Sergio Lopez Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Add a new section explaining the particularities of the microvm machine type for triggering a guest-initiated shut down. Signed-off-by: Sergio Lopez --- docs/microvm.rst | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/docs/microvm.rst b/docs/microvm.rst index 4cf84746b9..fcf41fc1f6 100644 --- a/docs/microvm.rst +++ b/docs/microvm.rst @@ -106,3 +106,24 @@ disabled:: -device virtio-blk-device,drive=test \ -netdev tap,id=tap0,script=no,downscript=no \ -device virtio-net-device,netdev=tap0 + + +Triggering a guest-initiated shut down +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +As the microvm machine type includes just a small set of system +devices, some x86 mechanisms for rebooting or shutting down the +system, like sending a key sequence to the keyboard or writing to an +ACPI register, doesn't have any effect in the VM. + +The recommended way to trigger a guest-initiated shut down is by +generating a ``triple-fault``, which will cause the VM to initiate a +reboot. Additionally, if the ``-no-reboot`` argument is present in the +command line, QEMU will detect this event and terminate its own +execution gracefully. + +Linux does support this mechanism, but by default will only be used +after other options have been tried and failed, causing the reboot to +be delayed by a small number of seconds. It's possible to instruct it +to try the triple-fault mechanism first, by adding ``reboot=t`` to the +kernel's command line.