From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [Regression] kvm-userspace: VM freezes after booting FreeDOS Date: Thu, 10 Jul 2008 23:22:59 +0200 Message-ID: <48767DB3.7090701@web.de> References: <52d4a3890807100847q5aef1a69hbd7179b018cb02ad@mail.gmail.com> <48763963.3010406@codemonkey.ws> <52d4a3890807101252h13c24b0ej35b4af71ac6b5b58@mail.gmail.com> <48766AE0.2050400@codemonkey.ws> <52d4a3890807101332v2cfe5604g78dc2d225e3c67d9@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig790C6D423E234A2DF08907B5" Cc: Anthony Liguori , kvm@vger.kernel.org, Avi Kivity , Rik van Riel To: Mohammed Gamal Return-path: Received: from fmmailgate03.web.de ([217.72.192.234]:56963 "EHLO fmmailgate03.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751653AbYGJVXF (ORCPT ); Thu, 10 Jul 2008 17:23:05 -0400 In-Reply-To: <52d4a3890807101332v2cfe5604g78dc2d225e3c67d9@mail.gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig790C6D423E234A2DF08907B5 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Mohammed Gamal wrote: > On Thu, Jul 10, 2008 at 11:02 PM, Anthony Liguori wrote: >> Mohammed Gamal wrote: >>> On Thu, Jul 10, 2008 at 7:31 PM, Anthony Liguori >>> wrote: >>> >>>> Mohammed Gamal wrote: >>>> >>>>> After updating my kvm-userspace tree to the latest git tree. I am n= o >>>>> more able to run FreeDOS. The VM freezes after choosing any of the >>>>> boot options. I am running both latest kvm.git and kvm-userspace.gi= t >>>>> >>>>> >>>> Can you bisect to the commit that broke it? >>>> >>>> Regards, >>>> >>>> Anthony Liguori >>>> >>> I did, it seems that commit 04c3265c95c12e7c6e73cfd07357c05db6a1bda8 >>> caused it. Everything works fine after I reverted it. >>> >> Thats: >> >> commit 04c3265c95c12e7c6e73cfd07357c05db6a1bda8 >> Author: Jan Kiszka >> Date: Fri May 16 09:21:47 2008 +0200 >> >> kvm: qemu: consolidate kvm_eat_signal >> With the io thread signals are rare. Remove looping over >> kvm_eat_signal and fold everything into kvm_main_loop_wait. >> Signed-off-by: Jan Kiszka >> Signed-off-by: Avi Kivity >> >> >> Hrm, that's disturbing. Unfortunately, the patch is a bit more than j= ust >> code motion. It does change the number of times the lock is released = and >> makes some minor changes to the code. Nothing obvious that would caus= e the >> breakage without digging into it. >> >> How did you create your freedos image? I'd like to try and figure out= what >> the problem is here since it may be causing other issues. >> >=20 > The image is a 500M image created using qemu-img (not using qcow). > FreeDOS was installed using the base CD image which you can get from > here: http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distribut= ions/1.0/fdbasecd.iso >=20 > After booting FreeDOS, there are a number of boot options with > different memory extenders, after selecting any option the system > freezes and I get [Stopped] in thr QEMU title bar. "Stopped" - interesting. Seems like something causes QEMU to stop the guest as if some breakpoint was injected. I just downloaded that image and gave it a try against vanilla kvm-70 and my own tree which is augment with guest debugging related patches. The former shows your observed behavior (Boot from CD, provide an empty HD image -> press '1' + ENTER -> press '1' -> "Stopped"). The latter kvm tree made QEMU leave with a #GP in the guest. That may point to a debug register related issue, and that patch you identified just happen to make it visible. However, will try to investigate. Jan --------------enig790C6D423E234A2DF08907B5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkh2fbMACgkQniDOoMHTA+ld5gCeI3ojJDYDjHac0PK1tEsWvSjW /FsAn32FrtnSLl1a+cfJdkiiojmr7+XK =q3z+ -----END PGP SIGNATURE----- --------------enig790C6D423E234A2DF08907B5--