From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JmZie-0002DS-GQ for qemu-devel@nongnu.org; Thu, 17 Apr 2008 15:24:28 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JmZia-0002DG-Pv for qemu-devel@nongnu.org; Thu, 17 Apr 2008 15:24:27 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JmZia-0002DD-LQ for qemu-devel@nongnu.org; Thu, 17 Apr 2008 15:24:24 -0400 Received: from fmmailgate02.web.de ([217.72.192.227]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JmZia-00023F-71 for qemu-devel@nongnu.org; Thu, 17 Apr 2008 15:24:24 -0400 Received: from smtp08.web.de (fmsmtp08.dlan.cinetic.de [172.20.5.216]) by fmmailgate02.web.de (Postfix) with ESMTP id 8BA89D92F6A2 for ; Thu, 17 Apr 2008 21:24:23 +0200 (CEST) Received: from [88.64.31.1] (helo=[192.168.1.198]) by smtp08.web.de with asmtp (TLSv1:AES256-SHA:256) (WEB.DE 4.109 #226) id 1JmZiZ-0005nI-00 for qemu-devel@nongnu.org; Thu, 17 Apr 2008 21:24:23 +0200 Message-ID: <4807A3E2.4070203@web.de> Date: Thu, 17 Apr 2008 21:24:18 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <47EE86E0.4070703@reactos.org> <9C7667CB-2CF0-4AC0-843B-6EF442196CAC@csgraf.de> <47F0B445.4030806@suse.de> <4804D254.5040301@siemens.com> <4805F4B0.5020802@siemens.com> <4806009E.8060407@suse.de> <48060F42.3080709@codemonkey.ws> <48070533.5060405@siemens.com> <48074740.4000202@codemonkey.ws> <48075A4C.5050205@siemens.com> <4807972C.8030807@codemonkey.ws> In-Reply-To: <4807972C.8030807@codemonkey.ws> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigA4E862611EB4BAF815D94BC0" Sender: jan.kiszka@web.de Subject: [Qemu-devel] Re: [PATCH] x86: Reboot CPU on triple fault - Version 4 Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigA4E862611EB4BAF815D94BC0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Anthony Liguori wrote: > Jan Kiszka wrote: >> Anthony Liguori wrote: >> =20 >>> Jan Kiszka wrote: >>> You can always check within the guest to see if it's rebooted (vi= a >>> uptime for instance). >>> =20 >> >> But you won't find the CPU state on triple fault there. >> =20 >=20 > Nor will you with your patch. Provided "-d cpu_reset" with Kevin's last patch, they are. I tried it, it worked, that's why I acked it. >=20 >>> It's extremely unlikely you'll ever see an OS triple fault in the wil= d >>> unless you're doing kernel development. Triple faulting requires a b= ad >>> IDT or a really bad page table both of which are not something an OS = is >>> likely to do by accident. If your OS is triple faulting, I highly do= ubt >>> it's just going to reboot and everything's going to be okay. >>> =20 >> >> There are various OSes out there in the wild. Not all of them conform = to >> common assumptions about how OSes typically look like. And once you >> start moving things under a different roof (like QEMU), you are better= >> off logging such /potentially/ critical events (specifically if that >> roof is a bit smaller due to missing segment limit and type checks). >> That's at least our situation ATM. >> =20 >=20 > It's not a question of whether it's logged, it's a question of whether > it gets logged *specially*. That's the crux of the discussion here. M= y > argument is that triple faults are not sufficiently special that they > warrant *special* logging. Depends on the POV. But I really think we loose nothing with the latest patch, rather gain a useful feature for certain (granted) corner cases. Jan --------------enigA4E862611EB4BAF815D94BC0 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4-svn0 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFIB6PmniDOoMHTA+kRAkxCAJ9Vf+IY+MvLfcdm0yX5QHewiMG26QCfSEGv JRmPR59OBk6EtHY8d1syca8= =sZjA -----END PGP SIGNATURE----- --------------enigA4E862611EB4BAF815D94BC0--