From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42337) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1g8K8c-0007gG-Oy for qemu-devel@nongnu.org; Fri, 05 Oct 2018 03:03:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1g8K8Y-00009M-OT for qemu-devel@nongnu.org; Fri, 05 Oct 2018 03:03:02 -0400 Received: from proxmox-new.maurer-it.com ([212.186.127.180]:40615) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1g8K8Y-0008Vg-Fz for qemu-devel@nongnu.org; Fri, 05 Oct 2018 03:02:58 -0400 References: <20181003091344.24496-1-d.csapak@proxmox.com> <20181004135110.GQ3667@redhat.com> From: Dominik Csapak Message-ID: <3672933a-18c4-8283-1318-c7b57fdf08d7@proxmox.com> Date: Fri, 5 Oct 2018 08:56:27 +0200 MIME-Version: 1.0 In-Reply-To: <20181004135110.GQ3667@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 0/1] add exit-script option to qemu List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= Cc: qemu-devel@nongnu.org, pbonzini@redhat.com On 10/4/18 3:51 PM, Daniel P. Berrang=C3=A9 wrote: > On Wed, Oct 03, 2018 at 11:13:43AM +0200, Dominik Csapak wrote: >> this patch aims to execute a script when qemu exits >> so that one can do cleanups when using --daemonize without >> having to use the qmp monitor >=20 > IMHO the idea of cleanup scripts run by QEMU itself is flawed. > QEMU will inevitably crash before cleanup scripts can be run, > so whatever mgmt app is using QEMU needs to be able to do > cleanup without QEMU's help. >=20 > I think this can be done more reliably with a wrapper script, > that spawns QEMU, waits for it to exit and then calls the > cleanup script. On Linux at least you can use prctl() with > PR_SET_CHILD_SUBREAPER so you can detect exit'ing of QEMU > even after it has daemonized. >=20 > Perhaps we could have such a wrapper script put in the > contrib directory >=20 > Regards, > Daniel >=20 Hi, for cleaning up after qemu crashes, you are completely right, (ignoring that the downscript for tap devices also never gets executed then), but this series has another use. With it, a user can determine the reason of a graceful shutdown (e.g., if it was by a signal, qmp or from inside) of qemu, especially when using -no-reboot without using qmp and using qmp for that is not very practical for everyone, or is there another way for that which i am missing? Regards, Dominik