From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ludovic =?UTF-8?Q?Court=C3=A8s?= <ludo@gnu.org>
Subject: bug#34276: =?UTF-8?Q?=E2=80=98guix?= system disk-im
 =?UTF-8?Q?age=E2=80=99?= successfully builds a bad image
Date: Sat, 21 Mar 2020 16:58:02 +0100
Message-ID: <875zex1z05.fsf@gnu.org>
References: <877eejfqmb.fsf@nckx>
 <7a36cb1fc7c68f5d63a324df49170cdc@waegenei.re>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable
Return-path: <bug-guix-bounces+gcggb-bug-guix=m.gmane-mx.org@gnu.org>
Received: from eggs.gnu.org ([2001:470:142:3::10]:45054)
 by lists.gnu.org with esmtp (Exim 4.90_1)
 (envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1jFgWd-0001nz-5F
 for bug-guix@gnu.org; Sat, 21 Mar 2020 11:59:04 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
 (envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1jFgWc-00078k-1t
 for bug-guix@gnu.org; Sat, 21 Mar 2020 11:59:03 -0400
Received: from debbugs.gnu.org ([209.51.188.43]:41858)
 by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16)
 (Exim 4.71) (envelope-from <Debian-debbugs@debbugs.gnu.org>)
 id 1jFgWb-00078c-Uh
 for bug-guix@gnu.org; Sat, 21 Mar 2020 11:59:02 -0400
Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2)
 (envelope-from <Debian-debbugs@debbugs.gnu.org>) id 1jFgWb-0005au-U6
 for bug-guix@gnu.org; Sat, 21 Mar 2020 11:59:01 -0400
Sender: "Debbugs-submit" <debbugs-submit-bounces@debbugs.gnu.org>
Resent-Message-ID: <handler.34276.B34276.158480629321412@debbugs.gnu.org>
In-Reply-To: <7a36cb1fc7c68f5d63a324df49170cdc@waegenei.re> (Brice
 Waegeneire's message of "Thu, 19 Mar 2020 20:05:08 +0000")
List-Id: Bug reports for GNU Guix <bug-guix.gnu.org>
List-Unsubscribe: <https://lists.gnu.org/mailman/options/bug-guix>,
 <mailto:bug-guix-request@gnu.org?subject=unsubscribe>
List-Archive: <https://lists.gnu.org/archive/html/bug-guix>
List-Post: <mailto:bug-guix@gnu.org>
List-Help: <mailto:bug-guix-request@gnu.org?subject=help>
List-Subscribe: <https://lists.gnu.org/mailman/listinfo/bug-guix>,
 <mailto:bug-guix-request@gnu.org?subject=subscribe>
Errors-To: bug-guix-bounces+gcggb-bug-guix=m.gmane-mx.org@gnu.org
Sender: "bug-Guix" <bug-guix-bounces+gcggb-bug-guix=m.gmane-mx.org@gnu.org>
To: Brice Waegeneire <brice@waegenei.re>
Cc: 34276@debbugs.gnu.org

Hi Brice,

Brice Waegeneire <brice@waegenei.re> skribis:

>> I investigated a bit.  I managed to get our code to cause a kernel=20
>> panic
>> upon failure (patch below).  However I fail to turn that guest kernel
>> panic into a different QEMU exit code.
>>=20
>> I tried to use the =E2=80=9Cpvpanic=E2=80=9D paravirtualized device (the=
 =E2=80=98pvpanic.ko=E2=80=99
>> module in the guest, and =E2=80=9C-device pvpanic=E2=80=9D on the QEMU c=
ommand line),
>> but unfortunately that thing is almost undocumented and I can=E2=80=99t =
get it
>> to turn the panic into a non-zero exit code, nor do I know if it=E2=80=
=99s
>> possible.
>>=20
>> Thoughts anyone?
>
> I looked a little into it and I have found how to use pvpanic.
> Unfortunately it's not as straight forward as getting a non-zero exit
> code form qemu. When pvpanic is loaded in a VM=CC=A3, as you did with=20
> =E2=80=9C-device
> pvpanic=E2=80=9D, generate events[0] on the QMP interface when a crash ha=
ppen
> and qemu either shutdown or pause when using --no-shutdown[1].
>
> (gnu build marionette) which use the =E2=80=9C-monitor=E2=80=9D interface=
 could be
> recycled to use =E2=80=9C-qmp=E2=80=9D a machine interface using JSON.
>
> Following is log of a QMP session where the guest panicked[2]:

Oooh, I see, thanks for digging into this!

Any idea how to implement it?  Is QMP a request/reply kind of interface
like the monitor?

Ludo=E2=80=99.